KR20080039537A - Method and apparatus for selecting delay values for a rake receiver - Google Patents

Abstract

Multipath components of transmitted data symbols are received with individual delays and processed by a RAKE having a number of fingers. A delay profile (31) indicating magnitudes for a first number of delay values is provided. Estimated magnitudes for a second number of delay values located between the first number of delay values are calculated by interpolation, and a combined delay profile (32) is provided by combining the magnitudes for the first and second number of delay values. Delay values for peaks in the combined delay profile are determined, and a number of peak delay values (P1, P2, P) comprising the largest peak are selected from the combined delay profile. At least some of the selected peak delay values are provided to the RAKE and assigned to the fingers. This allows a reduction of current consumption and dye area, while still providing delay values with sufficient resolution for the RAKE.

Description

METHOD AND APPARATUS FOR SELECTING DELAY VALUES FOR A RAKE RECEIVER}

The present invention relates to a method for receiving digital data symbols from at least two transmitters over a transmission channel of a communication network, wherein each multipath component of the transmitted data symbols is received with an individual delay, and the received signals are multiple Processed by a RAKE unit having a finger of the method, the method comprising providing a delay profile for each transmitter from a series of received pilot signals, the delay profile being at least one Indicative of the magnitude of the received signal level for each of the first number of delay values, resulting from the results of path search < RTI ID = 0.0 > The invention also relates to a receiver of coded digital data symbols and a corresponding computer program and computer readable medium.

In a wireless communication system, the physical channel between the transmitter and the receiver is generally formed by a wireless link. By way of example, the transmitter may be a base station and the receiver may be a mobile station or vice versa. In most cases, the transmit antenna is not narrowly focused towards the receiver. This means that the transmitted signal may be propagated through multiple paths. In addition to possible direct paths from the transmitter to the receiver, there are many other propagation paths caused by reflections from objects in the surrounding environment. Thus, a receiver may receive multiple instances of the same signal at different times, with different delays, where different parts of the signal may be various objects, such as buildings, moving vehicles or landscape details. Because it is reflected from.

These different parts of the signal are the source of the interference at the receiver. Depending on the time resolution and instantaneous phase relationship of the transmission system, parts having similar propagation distances are combined at the receiver to form separate multipath components. The effect of this coupling depends on the instantaneous relationship of carrier wavelength and distance difference, so this effect can be either enhancement or destructive for a given multipath component. In the case of attenuation interference, this combination significantly reduces the magnitude of the path gain for that path, i.e. there is fading. Thus, the gain of the actual path may temporarily decrease significantly due to fading.

Many transmission systems attempt to reduce the effects of multipath propagation and fading by using a receiver that combines data symbol energy from all multipath components. In Code Division Multiple Access (CDMA) and Wideband Code Division Multiple Access (WCDMA) systems, the energy of the different receiving portions of the signal can be used at the receiver by using a so-called RAKE receiver.

In these systems, spreading and despreading are used. Data is transmitted from the transmitter side using a spread spectrum modulation technique in which data is spread over a wide range of frequencies. Each channel is assigned a unique spreading code that is used to spread data over a frequency range. This spreading code is a pseudo-random noise code and consists of a binary sequence of ones and zeros called "chips", for example, distributed in a pseudo-random manner and having noise-like properties. The number of chips used to spread one data bit, ie chips / bits, may vary, depending at least in part on the data rate of the channel and the chip rate of the system. The duration of the chip is also used as a time unit at the receiver.

At the receiver, the received signal must be despread and demodulated with the same spreading code using the same chip rate to recover the transmitted data. In addition, the timing of the demodulation must be synchronized, i.e. the despreading code must be applied to the received signal at the correct moment, which can be difficult due to the multipath effect described above. The performance of a CDMA receiver is improved using a RAKE receiver, where each multipath component is assigned a despreader whose reference copy of the spreading code is delayed equal to the path delay of the corresponding multipath component. The outputs of the despreaders, ie, the fingers of the RAKE receiver, are then coherently combined to produce a symbol estimate.

Thus, the RAKE receiver needs to know the value of the multipath delay and channel impulse response for all paths. In order to achieve the best possible signal-to-noise ratio (SNR) at the output of the RAKE combiner, signal energy from as many physical paths as possible must be collected. The fluctuating delays of all known multipath components must be tracked and these paths must be discovered soon after new paths appear. This is generally accomplished using a path searcher unit having an observation window that is shorter than the full search area. In an actual delay estimation system, a path searcher unit is used periodically to rescan the delay range to detect a new path.

The performance of a CDMA receiver is highly dependent on the quality of the multipath delay detection unit. If the detected delay of the multipath is outside the correct value, the transmit power delivered by those paths is at least partially lost, and the noise level is increased, thus degrading the performance of the receiver.

In the case of a WCDMA system, detection of multipath delay is usually done as a two-step process.

First, a wide search is done to identify the location of the multipath delay. The resolution of this search, i.e. the distance between delays, can generally be on the order of one chip or less, and the time delays are usually evenly spaced apart. The device that does this search is referred to herein as a path searcher, and the set of delays processed by the path searcher is called a path searcher window. The number of time delays processed in the path finder window may be approximately 60 to 150. Usually, the received power or signal to interference ratio (SIR) for a particular delay is used as a reference for the quality of the delay. The resolution of the path finder is generally lower than that required by RAKE.

Then, a localized search is thus performed over the selected delay range, where the number of time delays can be approximately 20-50. The resolution of this search is usually on the order of 1/2 to 1/8 chips. As before, SIR or power is used as a quality measure. From the results of the localized search, a decision is made as to which delay to use to despread the data in the RAKE.

When calculating entries in the delay profile based on power or SIR values, a despreader needs to be assigned. Despreader operation is often done in hardware. As in the path finder, a series of despreaders that describe a series of equispaced time delays often consume much less die area, especially if the time delays have nothing to do with each other. Less current consumption than no. Localized retrieval uses a despreader with independent time delays. Generally speaking, wide area search and localized search consume the same amount of die area, but there are more despreaders in wide area search.

Thus, this two-stage solution with a significant number of despreaders has a correspondingly high current consumption and a large die area is occupied by the despreader. This is a disadvantage because there is a continuing need to reduce current consumption as well as die area of mobile terminals.

As an alternative to the two-stage solution, a high resolution wide area search can of course be done frequently to find the delay, but this solution requires much larger die area and has much higher current consumption, thus this solves this problem. Not the right way to do it.

US Patent Publication 2005/0047485 discloses a finger placement method and apparatus in a RAKE receiver. The fingers at the RAKE receiver may be placed using a delay resolution that is independent of the delay resolution used to generate the multipath delay profile, for example, in the path finder. Interpolation between measurement sample points in the delay profile can be used to determine the point quality of a finger placement grid point that is inconsistent with the retriever measurement. When the mobile terminal receives transmissions from two or more transmit antennas, finger placement may be jointly applied at the receiver based on the union of qualities from different transmit signals, but the scheduling of the corresponding path finder execution may be Not mentioned.

It is therefore an object of the present invention to provide a method for detecting multipath components from at least two transmitters, in which path searcher execution can be efficiently scheduled, wherein each transmitter is equally capable over a long period of time. A positive measurement time is given.

It is a further object of the present invention to provide a multipath component that allows for reduction of die area and current consumption required for the despreader in a two stage solution while at the same time providing a delay value with sufficiently high resolution for the RAKE. To provide a method of detection.

Summary of the Invention

According to the present invention, the method associates a counter with each of said transmitters, each time a digital data symbol is received from a given transmitter until the counter reaches a maximum counter value. Incrementing the counter by one, requesting a path search to be performed for the given transmitter when the associated counter reaches a first predefined value, and routing path search requests first-in-first-out ) Queuing the queue, activating the path search in the order in which the path searches are placed in the FIFO queue, and when the path search for the transmitter is activated, the counter associated with the transmitter is second predefined. The object is achieved in that it further comprises the step of decreasing by a value. As such, over a long period of time, an efficient way of scheduling path finder execution is achieved while ensuring that all transmitters to be measured are given the same amount of measurement time.

The method includes calculating, by interpolation, an estimated magnitude of a received signal level for a second number of delay values located between at least some of the first number of delay values, the first number of delay values. And providing a combined delay profile by combining magnitudes of received signal levels for the second number of delay values, determining delay values for peaks detected in the combined delay profile, the combined Selecting a plurality of peak delay values from among the peak delay values determined for the delay profile, wherein the selected peak delay values comprise at least a delay value representing the largest peak detected in the combined delay profile; and Provide at least some of the selected peak delay values to the RAKE unit and assign each provided peak delay value to a finger of the RAKE unit. It further comprises the step of being hit.

By using interpolation to estimate the intermediate signal level, sufficient resolution for RAKE can be achieved from wide path search in a relatively simple manner without increasing the current consumption or die area required for the despreader. Thus, this method relies only on global search to search and monitor the propagation channel time delay and to select a time delay for despreading data in the RAKE.

In one embodiment, at least some of the first number of delay values are equidistantly spaced, in which case each of the second number of delay values is two of the first number of delay values. It may be located in the middle of neighboring delay values.

The step of calculating the estimated magnitudes of the second number of delay values may be performed using polynomial interpolation.

In one embodiment, the step of selecting a plurality of peak delay values comprises: selecting a delay value representing the largest peak detected in the combined delay profile, the predetermined minimum interval of the delay value just selected. Excluding from the consideration all delay values within a strictly smaller distance, and repeatedly selecting a delay value representing the largest peak detected among the remaining delay values, until a given number of delay values are selected or combined Excluding all delay values within the distance that are strictly smaller than the predefined minimum interval of the delay value just selected, until all delay values of the selected delay profile have been selected or excluded from consideration. As such, delay values associated with weak power values can be eliminated, and a subset of delay values corresponding to the strongest power values are selected for use in the RAKE, so that a given minimum interval exists between the delay values. .

In an alternative embodiment, the step of selecting a plurality of peak delay values comprises: preselecting all delay values of the combined delay profile that represent magnitudes of the received signal level higher than a predefined threshold; Selecting a delay value representing the largest peak among the delay values, except for the delay values located at the predefined minimum intervals from the just selected delay values, Excluding from consideration consideration of delay values within a distance strictly less than twice the predetermined minimum interval, if a delay located at the predefined minimum interval from a previously selected delay value belongs to the preselected delay values, Select this value repeatedly and select the predefined maximum from the just selected delay value. Excluding from consideration the delay values within a distance that are strictly less than twice the predefined minimum interval of the just-selected delay value, except for the delay values located at small intervals, and given Repeating these steps for the remaining preselected delay values until a number of delay values are selected or until all preselected delay values are selected or excluded from consideration. Further, in this embodiment, delay values associated with weak power values can be eliminated and a subset of delay values corresponding to the strongest power values are selected for use in the RAKE, and thus the minimum given between the delay values. There is a gap. This embodiment also ensures that the selected delay values are as uniform as possible.

The method comprises generating a combined set of peak delay values from the selected peak delay values for each transmitter, the reduced peak delay value by selecting a plurality of largest peak delay values from the combined set of peak delay values. Generating a set, wherein no peak delay from a given transmitter is included in the reduced set of peak delay values and at least one peak delay from the given transmitter indicates a peak above a predefined threshold Generating a modified set of peak delay values by replacing the peak delay value of the weakest peak from the reduced set of peak delay values with the peak delay value of the largest peak from the given transmitter, and the modified peak delay. Provide a set of values to the RAKE unit and set each peak delay value of the modified set. Assigning to a finger of the RAKE unit. As such, the receiver may use information from two or more transmitters or cells. If different transmitters are not correlated at all, contributions from different transmitters are important.

In addition, an activated path search for a transmitter may provide a new search delay profile for that transmitter, in which case the method may include a plurality of largest peak delay values and the new search delay profile for the transmitter. Extracting the nearest neighbor delay values of these peaks from among them, and adding the percentage of the difference between the previously calculated magnitude and the corresponding magnitude from the new search delay profile to the previously calculated magnitude. By obtaining the previous magnitude provided for the transmitter by calculating the updated magnitude of the received signal level for that delay value for each delay value represented in the extracted delay values as well as in the previous delay profile. The step of updating the delay profile of the method further comprises. By updating the old delay profile to account for the new search delay profile instead of just using the new search delay profile, it is ensured that short noise peaks do not change the profile much.

When the percentage depends on comparing the magnitude from the new search delay profile with the previously calculated magnitude, there may be a bias in maintaining that delay if the delay is indicated as a high peak in the previous delay profile. On the other hand, a new high peak in the new search delay profile is also considered.

The method includes selecting a delay value representing the largest peak detected in the updated delay profile, excluding from consideration all delay values within a distance that is strictly smaller than a predefined minimum interval of the just selected delay value. Step, repeatedly selecting the delay value representing the largest peak detected among the remaining delay values, and until a given number of delay values are selected or when all delay values of the updated delay profile are selected or excluded from consideration. Excluding all delay values within a distance strictly less than a predefined minimum interval of the just selected delay value from consideration, and their nearest neighbor delay value among the selected delay values and the updated delay profile. Providing a monitored delay profile comprising a. As such, the delay values associated with the weak power value in the updated delay profile are selected as the monitored data profile, so that a given minimum interval exists between the delay values.

Each time the method receives a predetermined number of frames of digital data symbols, providing a combined delay profile and selecting a plurality of peak delay values from among the peaks of the combined delay profile. When further included-the monitored delay profile is used as the delay profile provided for the transmitter-it is ensured that new delay values based on the monitored delay profile can be provided to the RAKE at well defined intervals.

As mentioned, the present invention also relates to a receiver for receiving digital data symbols from at least two transmitters over a transmission channel of a communication network, wherein individual multipath components of the transmitted data symbols are received with individual delays. The receiver comprises a RAKE unit having a plurality of fingers for processing the received signals, the receiver providing a delay profile for each transmitter from a series of received pilot signals. Wherein the delay profile is generated from the results of at least one path search and indicates the magnitude of the received signal level for each of the first number of delay values.

When the receiver is configured to generate a delay profile provided for the transmitter from the results of at least one path search, the receiver also associates a counter with each of the transmitters, until the counter reaches a maximum counter value. Increments the counter associated with the given transmitter by one each time a digital data symbol of one frame is received from a given transmitter, and the path to be performed for the given transmitter when the associated counter reaches a first predefined value. Request a search, list path search requests in a first-in-first-out (FIFO) queue, enable path search in the order in which the path searches are put in the FIFO queue, and the path search for the transmitter And is further configured to decrement the counter associated with the transmitter by a second predefined value when activated. When, while ensuring an efficient way to give to receive an amount of measurement time all transmitters to be measured is the same throughout the period of long-term scheduling the path searcher runs is achieved.

The receiver also calculates, by interpolation, an estimated magnitude of the received signal level for a second number of delay values located between at least some of the first number of delay values, and the first number of delay values. And the magnitudes of the received signal level for the second number of delay values to provide a combined delay profile, determine delay values for peaks detected in the combined delay profile, and determine the combined delay. Select a plurality of peak delay values from among the peak delay values determined for the profile, wherein the selected peak delay values comprise at least a delay value representing the largest peak detected in the combined delay profile; Provide at least some of the values to the RAKE unit and assign each provided peak delay value to a finger of the RAKE unit. It may consist of. As such, a receiver is achieved that detects a multipath component that enables the reduction of die area and current consumption required for the despreader in a two-step solution while at the same time providing delay values with sufficiently high resolution for the RAKE.

In one embodiment, the receiver is configured to provide a delay profile for the transmitter such that at least some of the first number of delay values are equidistantly spaced, in which case the receiver is configured to provide the second profile. Each of the number of delay values may be configured to find in the middle of two neighboring delay values of the first number of delay values.

The receiver may be configured to calculate an estimated magnitude for the second number of delay values using polynomial interpolation.

In one embodiment, the receiver selects a delay value representing the largest peak detected in the combined delay profile, and all delay values within a distance that is strictly smaller than a predefined minimum interval of the delay value just selected. Are taken into account, and the delay value representing the largest peak detected among the remaining delay values is repeatedly selected, and all delay values of the combined delay profile are selected or taken into account until a given number of delay values are selected. It is configured to select a plurality of peak delay values by excluding all delay values within a distance that is strictly smaller than the predefined minimum interval of the delay value just selected, until excluded from. As such, delay values associated with weak power values can be eliminated, and a subset of delay values corresponding to the strongest power values are selected for use in the RAKE, so that a given minimum interval exists between the delay values. .

In an alternative embodiment, the receiver preselects all delay values of the combined delay profile that represent magnitudes of the received signal level higher than a predefined threshold and indicates the largest peak among the preselected delay values. Select a delay value, more than twice the predetermined minimum interval of the just-selected delay value and the just-selected delay value, excluding delay values located at the predefined minimum interval from the just-selected delay value; Except for taking into account delay values within a smaller distance, if a delay located at the predefined minimum interval from a previously selected delay value belongs to the preselected delay values, this value is selected repeatedly, and is now selected. Excluding the delay values located at the predefined minimum interval from the delay value, Delays in the distance that are strictly less than twice the predefined minimum interval of the just-selected delay value and the just-selected delay value are excluded from consideration, until a given number of delay values are selected or all preselected It is configured to select multiple peak delay values by repeating these steps for the remaining preselected delay values until the delay values are selected or excluded from consideration. Also in this embodiment, the delay values associated with the weak power value can be eliminated, and a subset of the delay values corresponding to the strongest power value is selected for use in the RAKE, so that the given minimum interval is between the delay values. Exists in This embodiment also ensures that the selected delay values are spaced at as uniform intervals as possible.

The receiver generates a combined peak delay value set from the peak delay values selected for each transmitter and reduces the peak delay value set by selecting a plurality of largest peak delay values from the combined peak delay value set. And if no peak delay from a given transmitter is included in the reduced set of peak delay values and at least one peak delay from the given transmitter indicates a peak that is higher than a predefined threshold, Replacing the peak delay value of the weakest peak from the reduced set of peak delay values with the peak delay value of the largest peak from the given transmitter to generate a modified set of peak delay values, and And provide each peak delay value of the modified set to the RAKE unit. It is further configured to assign to a finger. As such, the receiver may use information from two or more transmitters or cells. Since different transmitters are not correlated at all, contributions from different transmitters are important.

In addition, the receiver may be configured to provide a new search delay profile for the transmitter in response to an activated path search for the transmitter, in which case the receiver may be configured to provide the delay values of the plurality of largest peaks and the transmitter. Extract the nearest neighbor delay value of these peaks from the new search delay profile for and add the percentage of the difference between the previously calculated magnitude and the corresponding magnitude from the new search delay profile to the previously calculated magnitude. Thereby obtaining an updated delay profile, for each delay value represented in the extracted delay values as well as the previous delay profile, by calculating the updated magnitude of the received signal level for that delay value, Additionally to update the previous delay profile provided for the transmitter It can be generated. By updating the old delay profile to account for the new search delay profile instead of just using the new search delay profile, it is ensured that short noise peaks do not change the profile too much.

When the percentage depends on comparing the magnitude from the new search delay profile with the previously calculated magnitude, there may be a bias in maintaining that delay if the delay is indicated as a high peak in the previous delay profile. On the other hand, a new high peak in the new search delay profile is also considered.

The receiver selects a delay value representing the largest peak detected in the updated delay profile and excludes from consideration all delay values within a distance that is strictly smaller than a predefined minimum interval of the just selected delay value, Among the remaining delay values, the delay value representing the largest peak detected is repeatedly selected, and a given number of delay values are selected or until all delay values of the updated delay profile are selected or excluded from consideration. A monitoring including the selected delay values and their nearest neighbor delay values, except for taking into account all delay values within a distance that is strictly smaller than the predefined minimum interval of the just selected delay value. It may be further configured to provide a delay profile. As such, the delay values associated with the weak power value in the updated delay profile may be eliminated, and a subset of the delay values corresponding to the largest power value is selected as the monitored delay profile, such that the given minimum interval is the delay values. Exists in between.

The receiver provides a combined delay profile each time a predetermined number of digital data symbols are received, selects a plurality of peak delay values from among the peaks of the combined delay profile, and selects the monitored delay profile. If further configured to use as a delay profile provided for the transmitter, new delay values based on the monitored delay profile may be provided to the RAKE at well defined intervals.

In some embodiments, the receiver can be a WCDMA receiver.

The invention also relates to a computer program and a computer readable medium having a program code means for performing the above method.

The present invention is now described in more detail with reference to the drawings.

1 is a diagram illustrating an example of multiple paths between a base station and a mobile station.

FIG. 2 is a diagram illustrating a power delay profile for the paths illustrated in FIG. 1.

3 is a diagram illustrating a sampled delay profile corresponding to the profile shown in FIG. 2.

4 is a diagram illustrating an outline of a RAKE receiver.

5 shows how the counter for scheduling route finder execution is incremented and decremented.

6 is a flow diagram illustrating an overview of route finder scheduling.

7 and 8 illustrate a series of delay profiles illustrating updating of monitored delay profiles.

9 is a flowchart illustrating the selection of delay values for RAKE.

10 illustrates a series of delay profiles illustrating the selection of delay values for RAKE.

1 shows a situation in which a base station 1 and a mobile station 2 in a wireless communication system communicate with each other. As an example, the signal transmitted from the base station 1 is received by the mobile station 2. However, the transmitted signal travels along a number of paths from the base station to the mobile station. In this case, there is a propagation path 3 without direct obstacles, but in addition to this direct path, there are a number of indirect paths due to reflections from objects in the surrounding environment. Two such paths are shown in the figure. One indirect path 4 is reflected from the house 5, while another path 6 is due to reflection from another building 7.

Since part of the signal transmitted through one of the indirect paths 4, 6 must travel a longer distance to reach the mobile station 2 compared to the part of the signal traveling through the direct path 3. , Multiple instances of the same signal are received by the mobile station 2 at different times, ie with different time delays.

Thus, when the pilot signal is transmitted from the base station 1, the power P received as a function of time t at the mobile station 2 may appear as illustrated in FIG. 2 showing an example of a power delay profile. . This power delay profile shows all signals received at the mobile station, including noise and interference signals. However, only the peaks in the power delay profile correspond to the multipath component of the transmission signal. These peaks together form the impulse response of the channel. In FIG. 2, the peak P ₃ received at time t ₃ corresponds to the direct path 3 in FIG. 1, while the peaks P ₄ , P ₆ received at time t ₄ , t ₆ . Respectively correspond to the indirect paths 4 and 6 in FIG. 1. Thus, as an example, it can be seen that the delay of the path 6 (corresponding to the peak P ₆ ) is greater than the delay of the path 3 (corresponding to the peak P ₃ ).

(단,

, 즉 가능한 전체 지연 범위)에 대해, 대응하는 전력값

이 나타내어져 있다. 이 경우에, 전력 지연 프로파일의 이용가능한 추정치는 똑같은 간격있는 샘플들

의 연속적인 시퀀스를 구성하며, 여기서

는 지연축(delay axis)의 0 위치의 가능한 시프트(shifting)이다.In general, the delay profile of the received signal is not available as a continuous curve as shown in FIG. Instead, this delay profile consists of multiple sample values. This is shown in FIG. 3, which shows a sampled power delay profile corresponding to the continuous delay profile shown in FIG. 2. Each delay value

(only,

, I.e., the total possible range of delay,

Is shown. In this case, the available estimate of the power delay profile is equally spaced samples.

Constitute a continuous sequence of, where

Is a possible shift of the zero position of the delay axis.

The mobile station 2 and the base station 1 may, for example, be configured for use in a Code Division Multiple Access (CDMA) system or a Wideband Code Division Multiple Access (WCDMA) system, in which case the mobile station 2 Can use a RAKE receiver that can identify and track various multipath signals for a given channel. As such, the energy or power of several multipath components may be used at the receiver. At the RAKE receiver, each multipath component is assigned a despreader with a reference copy of the spreading code that is delayed equally to the path delay of the corresponding multipath component. The despreaders, i.e., the outputs of the fingers of the RAKE receiver, are then coherently combined to produce a symbol estimate. Thus, the RAKE receiver must know the values of the multipath delay and channel impulse response for all paths. Signal energy from as many physical paths as possible must be collected. This information can be obtained from the delay profiles.

Although reference is made here to a RAKE receiver in a mobile station, it should be noted that the algorithm described below can be used in any CDMA receiver, i.e., in a mobile station or a base station, and the transmission direction is uplink or downlink. It can be.

Since the structure of the propagation channel does not remain constant over time, the delay of the existing path changes, the old paths disappear and new paths appear. The changing delays of all known multipath components should be tracked and they should be discovered soon after the new path appears. Thus, in some implementations, a limited-range path searcher, which is rarely activated to redetect existing paths that are temporarily fading, is generally used. This is illustrated in FIG. 4, which shows an overview of the RAKE receiver 10.

At the receiver 10, the received spread data signal is provided to the path finder 11 and the RAKE unit 12. The path searcher 11 is a device that periodically calculates an instantaneous impulse response estimate (complex value or power, signal to interference ratio) over a range of delays, also called a path search window. The complex or power value for a given delay value can be estimated, for example, by correlating the received data for the pilot symbol with a properly delayed copy of the spreading sequence. Since the path finder 11 is conventionally only used to detect the presence of a path, its output resolution is generally lower than that required by the RAKE unit 12. Detected path delays, ie delays representing peaks in the delay profile, are then processed in delay processing 13 and passed to RAKE unit 12 and channel estimator 14. In the same figure, there is a feedback signal from the delay process 13 to the path finder 11. This is to adjust the center of the path finder window to resolve changes in the propagation channel time delay profile.

The received signals are then despread in RAKE unit 12, where each reported delay is assigned a RAKE finger, and each RAKE finger provides a complex despread data symbol. In channel estimator 14, the channel estimate for each path is calculated from the despread data symbol provided by RAKE unit 12 and the detected delays provided by path finder 11. At combiner 16, the despread data symbols provided by RAKE unit 12 are multiplied by the conjugate channel estimate, and the result is used for further decoding at decoder 17.

는 총 전송 전력에 대한 CPCH의 PN 칩별 수신 에너지의 비율이다, 즉

이다. 상세하게는,

및 RSCP가 네트워크에 주어진 셀의 품질을 알려준다. 실제로, RSCP 및 RSSI가 계산되고, 이 계산이 이어서

를 제공한다.In a WCDMA network, measurements of signal quality from neighboring cells are generally reported periodically, for example based on pilot signals from the Common Pilot Channel (CPICH). Three signal quality measurements are performed for the Common Pilot Channel (CPICH). Received Signal Strength Indicator (RSSI) is defined as total received power, including signal and interference, measured at the antenna connector, and is received signal code power (RSCP). Is the received power from the CPCH,

Is the ratio of the received energy per PN chip of the CPCH to the total transmit power, i.e.

to be. Specifically,

And RSCP informs the quality of a given cell in the network. In practice, RSCP and RSSI are calculated, which is followed by

To provide.

에 대한 누적된 신호의 강도는 이 시간 지연에 포함된 전력

을 반영한다. 이 강도가 지정된 노이즈 플로어(noise floor)보다 높은 것으로 판정되는 경우, 이는 다중 경로를 나타내는 것으로 말해지고, 그의 전력이 RSCP에 기여한다.The path finder 11 and the delay process 13 calculate the RSCP and RSSI. The received signal is correlated with the scrambling code and the CPICH channelization code for the cell, i.e., the CPICH symbols are despread and then accumulated. This is done for a given number of time delays. Given delay

The accumulated signal strength for is the power included in this time delay.

Reflects. If it is determined that this intensity is higher than the specified noise floor, it is said to represent a multipath, and its power contributes to the RSCP.

In the case of a WCDMA system, detection of multipath delay has conventionally been done as a two-step process. First, a wide and relative coarse path search of a wide area is performed to identify the location of the multipath delay. The resolution of this search, i. The series of delays handled by the path finder in this search is called the path finder window. The number of time delays handled in the path finder Winduo is approximately 60 to 150. Usually, the received power or signal to interference ratio (SIR) for a particular delay is used as a reference for the quality of the delay.

As mentioned, since the resolution of this first search is generally lower than that required by RAKE, a localized and finer search has conventionally been performed over a selected range of delays, The number of time delays here is approximately 20-50. The resolution of this search is usually on the order of 1/2 to 1/8 chips. As before, SIR or power is used as a quality measure. From the results of the localized search, it is determined which delay to use to despread the data in the RAKE.

Since the two-step solution requires a significant number of despreaders, it would be beneficial if localized searches could be avoided. Thus, in the following, the search for and propagation of the propagation channel time delay, the selection of the time delay to despread the data, the adjustment of the path finder window, and the calculation of the radio link measurement quality value from the monitored cells A method of relying only on wide search is described.

In the following description, it is assumed that the resolution of the global search is 1/2 chip. However, the same reasoning can be used for a path finder operating at 3/4 chip or chip resolution. The accuracy of the delays chosen to despread the data is given by the resolution of 1/4 chip. In other words, the method described below is easily adjusted to solve finer or more coarse resolution.

를 제공하는 것으로 가정한다.The function of the route finder itself is known and is not described in further detail here. The path finder 11 or delay processing 13, as described above, receives the received signal strength indicator RSSI ^samp , ie the total received power and cell c for the frequency we are at when we are running the path finder. And d, provided that d is taken from a series of time delays spaced at equal intervals in time.

Assume to provide.

First, we describe how to schedule path searcher activation for different cells and in what order the post-processing of the results of the path searcher should be done. Although the proposed scheduling scheme is easy to implement, it is flexible enough to cope with dynamic path finder activation time scheduling.

The delay for despreading data in RAKE is assumed to be selected every T _{delay selection} frame. This is a parameter that can vary depending on the speed of the mobile and the frequency at which the new propagation channel delay occurs. Measurement information such as received signal code power RSCP and received signal strength indicator RSSI is collected every T _measurement frame. The value of T _measurement depends on the cell mode in which we are specified by higher layer scheduling. For example, T _measurement is 20 frames in Cell DCH (Dedicated CHannel) mode.

For example, a frame counter n _c initialized to zero is associated with every cell c. This counter increments by one every frame to its maximum value N _c . This counter is decremented by Δn _c each time the path finder for the cell is activated. Counter (n _c ) is T _delay As soon as _selection is reached, this cell is placed in a first-in-first-out (FIFO) queue or list that will run the path finder for the cell in question. In general, we select Nc as the 1.5 T _{delay selection} and Δnc as the T _{delay selection} . Note that the counter n _c continues to increment its value whether or not the cell is in the queue. In the proposed parameter setting, we know that if the cell has to wait for some time in the queue before receiving the service, this is remembered since the counter n _c may reach its maximum. In this case, new path finder activation for the cell is queued within the 0.5 T _{delay selection} frame. Thus, the reason N _c is greater than T _{delay selection} is due to any unexpected delay (due to the use of the path detector's higher priority) in the path finder activation for the cell from the time the cell is queued until the cell is executed. This is to cope with. Over time, we run the path finder on average every T _{delay selection} frame. Here, we assume that on average it is possible to schedule all required path finder activations, ie T _{delay selection} is not too small. If each path finder activation is 4 slots long, the T _{delay selection} may be 6 frames or more.

This is shown in FIG. It can be seen that the counter for a given cell is reset to _zero at time t ₀ . After one frame, the counter is incremented by _one , and this is repeated until the counter at time t ₁ reaches T _{delay selection} (which is set to six frames here), and the cell is queued for the path search to be performed. Is placed. In this situation, it is assumed that the path search for the cell can be activated within a short time. Thus, within the next frame, at time t ₂ , the counter value is reduced by Δn _c (where T _{delay selection} , ie equal to 6 frames) by activation of the path finder, and thus the counter value is again zero. The counter continues to increment by 1 after each frame.

Next, a situation is shown in which activation of a cell is delayed a few frames after being placed in a queue for cell path search. In other words, at time t ₃ , the counter reaches T _{delay selection} and the cell is placed in the queue. However, since the path search is not actually activated until a few frames later, the counter is still incremented two or more times before the counter value is decreased by Δn _c at time t ₃ by activation of the path searcher. However, at this time the counter value is only reduced to the value 2, so that already at time t ₅ , the counter reaches T _{delay selection} again and the cell is placed in the queue. Thus, although the actual activation of the path finder was delayed, it can be seen that after the T _{delay selection} the cell is placed in the queue after the cell was previously placed in the queue.

Finally, a situation with a longer delay is shown. At time t ₆ , the counter reaches its maximum value N _c (which is set here to the value 9 (equivalent to 1.5 T _{delay selection} )), and the counter remains until the path finder is last activated at time t ₇ . Stay at the value. At this time, the counter value is reduced only to the value 3, so that already at time t ₈ , the counter reaches T _{delay selection} again and the cells are placed in the queue. Thus, from the values used in this example, it can be seen that even after a long delay, the cell is queued again within 0.5 T _{delay selection} after activation of the path finder.

Regarding the measurement, the series of cells we measure or receive data from is updated every T _measurement . Knowing how many cells we are processing during the measurement interval gives a clue as to how many RSSI ^samp samples we can average or filter during the measurement interval to reduce noise in the RSSI estimation. At the frequencies we are dealing with, let's denote the total number of cells in N _RSSI . The filter parameter in the filtering of RSSI ^samp values will then depend on the N _RSSI . This is used below.

We now describe how delay selection, measurement, and path finder window placement are interconnected. 6 shows a flowchart 100 that provides an overview of the flow of operations. Note that, in the two rhombus boxes 106 and 108, it is queried whether there is a request for measuring information or for updating the delay used to despread the data in the RAKE. When such a request comes in is determined by the scheduling assumption described above. Note that the request may not be processed immediately if other blocks are currently being processed. Then, we deal with the details of each step of the flowchart.

Step 101 polls a list of pending path finder activations, that is, said queue for the path search to be performed, and selects the next item in the list or queue. This step activates path finder activation as soon as it can find the contiguous slots needed to execute path finder activation. We can always assume that we know the transmission pattern at least one frame ahead. Once we have activated the Path Finder activation, we start processing the information from the just completed Path Finder activation (i.e. after step 103) (step 102).

As another alternative, we can schedule the route finder to perform a predetermined number (ie, four at a time) activation while processing the completed results. In step 102, for the latter implementation, we then check whether all completed path retriever activations have been processed, and if so, construct a sequencer that controls the path retriever with another set of path retriever activations. The process then proceeds to process or continue with the completed path retriever results.

First, in step 103, the RSSI value is updated. The RSSI ^samp sample value, calculated over the length of the path locator activation, is provided by the path locator hardware block. The filtered received signal strength indicator RSSI _filt can thus be updated as follows.

는 상기한 N_RSSI의 함수이다. 보다 정확하게는,

는 다음과 같이 정의될 수 있다.Where filtering factor

Is a function of N _RSSI described above. More precisely,

May be defined as follows.

Here, the floor function rounds to the next nearest small integer value.

는 1로 설정될 수 있다. 다른 대안으로서, 우리는 측정 기간에 걸쳐 저장된 RSSI 샘플들의 이동 평균을 계산하고 이를 RSSI_filt로서 저장할 수 있다.By selecting the filtering factor in this way, we basically approximate the average of all RSSI ^samp samples over the measurement interval T _{delay selection} . If this is the first sample,

May be set to one. As another alternative, we can calculate the moving average of RSSI samples stored over the measurement period and store them as RSSI _filt .

Then, in step 104, the monitored time delay and corresponding power value are updated. Note that the monitored time delays are usually stored and handled in software. Thus, despite the fact that the path finder calculates a fixed number of quality values for delays that are spaced at equal intervals, there is a point of interest to minimize the number of monitored time delays for each cell. . Selecting the entire path finder window as the monitored delay set is therefore not a suitable option, so that, for example, multiple delays with the largest power value are selected as the monitored delay set. In step 104, these monitored time delays and corresponding power values are updated to account for the path search just performed. Thus, instead of just using the delay of the new path search, the already monitored delays are updated taking into account the previous values. This can be done by a delay update function which will now be described.

, 그의 전력값

, 및 그의 새로운 샘플

이다. 게다가, 아마도 새로운 시간 지연의 세트

과 그의 전력값

, 및 노이즈 레벨

이다. 이 함수의 출력은 갱신된 모니터링된 시간 지연 세트

및 그의 전력값

이다. 이 함수에 의해 사용되는 파라미터들은 전력값

, 새로 발견된 지연들에 대한 페널티 파라미터(penalty parameter)

, 필터링 파라미터

, 및 적어도 1/4 칩 4개 간격으로 떨어져 있어야만 하는 피크들의 최대수 N_Peaks을 비교할 때 사용되는 문턱값 세트이다.The delay update function is a function that updates a set of monitored delays given a set of monitored delays and a possible new set of delays. Inputs to this function are the set of monitored time delays

, Its power value

, And his new sample

to be. Besides, perhaps a set of new time delays

And its power value

, And noise levels

to be. The output of this function is an updated set of monitored time delays.

And its power value

to be. The parameters used by this function are power values

Penalty parameter for newly discovered delays

, Filtering parameters

, And a threshold value set to be used when comparing the maximum number N of peaks _Peaks at least 1/4 must be apart into four chip intervals.

In the present situation, a delay update function can be used with the following inputs.

는 τ_c와 같고(단, τ_c는 셀 c에 대한 모니터링된 지연 세트임),-

It is equal to τ _c (stage, τ _c is the monitored delay set for the cell being c),

이며, 여기서 경로 검색기의 출력은 셀 c에 대한 P_c,d 및 d에 의해 인덱싱된 시간 지연으로서 나타내어지고, τ(d)는 인덱스 d의 대응하는 시간 지연에의 매핑이며,-

Where the output of the path searcher is represented as the time delay indexed by P _{c, d} and d for cell c, τ (d) is the mapping of the index d to the corresponding time delay,

는 저장된 값 P_c에 의해 주어지고,-

Is given by the stored value P _c ,

이며, 여기서

는 현재의 경로 검색기 활성화에서의

최대 피크 및 그의 1/2 칩 이웃들에 대응하는 지연 세트이다. 여기서 하드웨어로 또는 소프트웨어로 가장 큰

개 피크들을 추출하는 분류 함수를 갖는다는 것을 암시적으로 알 수 있다. 분류 함수는 가장 큰 피크 및 그의 이웃들을 선택함으로써 진행하며, 이들 지연을 추가적인 고려로부터 제외시키고, 이어서

개 피크들이 선택될 때까지, 계속하여 나머지 지연들 중에서 가장 큰 피크 및 그의 이웃들을 검색한다. 명백하게도, 경로 검색기 윈도우 밖에 있는 어떤 1/2 칩 이웃이라도

세트의 일부가 아닌데, 그 이유는 연관된 전력값이 없기 때문이다.-

, Where

In the current path finder activation

Delay set corresponding to the maximum peak and its half chip neighbors. Where hardware or software is the largest

It can be seen implicitly that we have a classification function to extract dog peaks. The classification function proceeds by selecting the largest peak and its neighbors, excluding these delays from further consideration, and then

Until the peaks are selected, we continue to search for the largest peak and its neighbors among the remaining delays. Apparently, any 1/2 chip neighbor outside the path finder window

It is not part of the set because there is no associated power value.

가 RSSI_filt에 의해 주어지는 것으로 한다.- noise

Is given by RSSI _filt .

The parameter values can be selected as follows.

parameter A reasonable range of values Examples of reasonable values

0 to 0.1 0

0 to 0.1 0

0.05 to 1 0.125

0.05 to 1 0.0625

0.05 to 1 0.5

0.02 to 0.2 0.1

6 to 12 10

0 or 1 0

및

의 합집합에 대한 전력값을 조정하는 것으로 시작한다. 우리는 조정된 전력값을

로 표기한다. 이하에서

는 시간 지연 τ에 대응하는 인덱스이다. 이하의 조건문이 이어서 실행된다.We delay time

And

Begin by adjusting the power values for the union of. We can adjust the power

It is written as. Below

Is an index corresponding to the time delay τ. The following conditional statements are subsequently executed.

이고

인 경우,

ego

If is

의 정의로부터, 우리는 지연이 모니터링된 세트의 일부인 경우 지연을 유지하는 데 바이어스가 있다는 것을 알고 있다.

의 두번째 행은 아주 강한 샘플(세번째 행)과 아주 약한 샘플(첫번째 행)의 사례들 간의 원만한 천이를 생성하기 위한 것이다. 이 생각은 대부분 첫번째 행이 활성화되도록, 즉 샘플들의 필터링이 우선적이도록 문턱값 및

가 선택되어야만 한다는 것이다.New power value

From the definition of, we know that there is a bias in maintaining the delay if the delay is part of the monitored set.

The second row of is to create a smooth transition between the cases of very strong sample (third row) and very weak sample (first row). The idea is that in most cases the threshold is such that the first row is active, i. And

Must be selected.

에 대해 이전의 갱신을 다음과 같이 일반화할 수 있다.We have any filter constant

We can generalize a previous update to

값들이 어떻게

에 또는 단지 2개의 레벨에 관련되어 있는지에 따라 이것을 다른 필터링의 훨씬 더 많은 레벨들로 일반화할 수 있다.Obviously, we

How the values are

You can generalize this to much more levels of different filtering depending on whether or not it is related to only two levels.

이 없는 경우, 즉 정의되지 않은 경우(이하 참조), 우리는

를

와 같은 것으로 한다.Previous value

If there is no, that is not defined (see below), we

To

Shall be the same as

이고

인 경우,

ego

If is

이다.

to be.

This means that the new delay is careful to put it in the monitored set unless it is a good quality delay.

이고

인 경우,

ego

If is

이다.

to be.

이 없는 경우, 즉 정의되지 않은 경우(이하 참조), 우리는

를

와 같은 것으로 한다.Previous value

If there is no, that is not defined (see below), we

To

Shall be the same as

및

의 합집합에 대한 전력값을 가지며, 지연값들의 수를 모니터링된 값 또는 피크의 최대 수

로 감소시키기 위해 지연 절단 및 선택 함수(delay pruning and selection function)가 시간 지연 세트

, 대응하는 전력값들

, 및 노이즈

에 적용될 수 있다.We now delay time

And

Has a power value for the union of and the number of delay values is the maximum number of monitored values or peaks

Delay pruning and selection functions are used to reduce

Corresponding power values

, And noise

Can be applied to

이다. 이 함수의 출력들은 기껏해야 서로 적어도

간격으로 떨어져 있는

개의 지연이다. 이 함수에 의해 사용되는 파라미터들은 우리가 선택하고자 하는 지연들의 최대수

, 지연들을 선택하기 위한 문턱값

및

, 모든 지연들이 이로부터 선택되어야 하는 시간 윈도우

(

인 경우, 지연들이 어떤 시간 윈도우 내에 들어갈 필요가 없음), 지연들 간의 최소 간격

(

의 단위는 1/4 칩임), 셀의 첫번째 경로의 시간 지연

, 및 1로 설정될 때 선택된 지연들을 가능한 한 균일한 간격으로, 즉 고정된 격자로 두려고 시도하는 파라미터

이다. 이 상황에서, 파라미터

는 0으로 설정된다.The delay truncation and selection function is a function of removing time delays associated with weak power values such that, given a series of delays for a cell, there is a given minimum interval between delays, where The subset of delays is selected. Inputs to this function are given a number of delays, their power values, and noise levels

to be. The outputs of this function should be at least

Apart at intervals

Delays. The parameters used by this function are the maximum number of delays we want to select

Threshold for selecting delays

And

, The time window in which all delays should be selected from

(

Delays do not need to fall within any time window), the minimum interval between delays

(

Is a quarter chip), the time delay of the cell's first path

A parameter that attempts to place the selected delays as uniformly as possible, i.e. with a fixed grid when set to

to be. In this situation, the parameter

Is set to zero.

내에 들어가야 한다는 요건이 있는 경우, 이 함수는 윈도우

밖에 있는 모든 지연들을 제거하는 것으로 시작한다. 셀의 첫번째 경로

가 구간 밖에 있는 경우, 그의 다른 경로 전부도 역시 누락된다. 이러한 이유는 이러한 셀이 데이터를 수신하는 데 사용되는 셀의 리스트로부터 가능한 한 곧바로 제거되어야만 하기 때문이다.Delays windows

If there is a requirement to be within, this function

Start by removing all the delays that are out there. Cell's first path

If is outside the interval, all of its other paths are also missed. This is because these cells must be removed from the list of cells used to receive the data as soon as possible.

및 노이즈 레벨

의

인 지연들이 선택된다.

가 음수인 경우, 첫번째 (전력) 문턱값이 적용되지 않으며,

가 음수인 경우, 두번째 (노이즈) 문턱값이 적용되지 않는다.At least the maximum power value

And noise level

of

Phosphorus delays are selected.

If is negative, the first (power) threshold does not apply,

If is negative, the second (noise) threshold does not apply.

가 0으로 설정되는 경우에 행해지며, 이것이 여기에서의 사례이다. 이제 막 선택된 지연 세트에 대해, 가장 큰 전력값을 갖는 지연이 선택되고, 이는 피크 'P'로 태깅되고, 새로 발견된 피크에서

보다 엄밀하게 더 작은 거리 내의 모든 지연들이 제거된다. 나머지 지연들, 즉 태깅되지도 제거되지도 않은 지연들 중에서, 가장 큰 전력값을 갖는 지연이 선택되고, 이는 피크 'P'로서 태깅된다. 다시 말하면, 새로 발견된 피크에서

보다 엄밀하게 더 작은 거리 내의 모든 지연들이 제거된다. 모든 지연들이 태깅되거나 제거될 때까지 또는

개 지연들이 태깅될 때까지 이 프로세스가 계속된다. 출력 지연 세트는 'P'로서 태깅된 지연들에 의해 주어진다.The following operations

Is set to 0, this is the case here. For the delay set just selected, the delay with the largest power value is selected, which is tagged with peak 'P' and at the newly found peak.

More strictly all delays within a smaller distance are eliminated. Of the remaining delays, i.e., those that are neither tagged nor removed, the delay with the largest power value is selected, which is tagged as the peak 'P'. In other words, at the newly discovered peak

More strictly all delays within a smaller distance are eliminated. Until all delays are tagged or removed

This process continues until the dog delays are tagged. The output delay set is given by the delays tagged as 'P'.

, 대응하는 전력값들

, 및 파라미터 선택

1/4 칩 4개와 같은

, 및

을 갖는 노이즈

에 적용된다. 시간 지연들의 결과 세트는

라고 한다.The delay truncation and selection function just described is a set of time delays.

Corresponding power values

, And parameter selection

Such as 4 1/4 chips

, And

Noise with

Applies to The result set of time delays is

It is called.

는 이제 그 세트 내의 각각의 지연의 1/2 칩 이웃들과 함께 세트

와 같게 되는데, 그 이유는 이들 이웃이 이하에서 필요하게 되기 때문이다. 이제,

내의 지연이 세트

내에 포함되어 있는 경우, 이는 세트

에 의해 제공되는 그와 연관된 전력값을 갖게 되고, 그렇지 않은 경우, 우리는 전력값을 정의되지 않은 것으로 설정한다. 시간 지연 세트

에 대응하는 전력값의 결과 세트는

로 표기된다.New monitored time delay set

Is now set with half chip neighbors of each delay in the set

This is because these neighbors are needed below. now,

Delay within this set

If contained within, this is a set

We have a power value associated with that provided by, otherwise we set the power value to undefined. Time delay set

The result set of power values corresponding to

It is indicated by.

및

를 대체한다. 이것이 단계(104)를 완료한다.The output of the delay update function is the stored value

And

To replace This completes step 104.

로 지정된 세트이다. 그 다음 프로파일(22)은 이제 막 수행된 새로운 경로 검색의 결과를 나타낸 것이다. 이 예에서, 검색의 결과가 1/2 칩의 분해능을 갖는 64개의 등간격으로 떨어져 있는 시간 지연들을 포함하고 있음을 알 수 있다. 이 프로파일(22)으로부터, 가능한 새로운 지연 세트

가 새로운 경로 검색 결과에서의

(여기서 10으로 설정됨)개의 가장 큰 피크 및 이들의 1/2 칩 이웃들에 대응하는 지연 세트로서 발견된다. 이것이 도 7의 세번째 프로파일(23)에 나타내어져 있으며, 여기서 10개의 가장 큰 피크가 굵은 선으로 나타내어져 있고 이들의 1/2 칩 이웃들은 가는 선으로 나타내어져 있다.The functions of step 104 are also represented by the delay profile shown in FIGS. 7 and 8. Top profile 21 in FIG. 7 is an example of a set of monitored delays stored for a given cell c after previous path finder activation. This is the above

The set specified by. The profile 22 then shows the results of the new path search just performed. In this example, it can be seen that the result of the search includes 64 equally spaced time delays with a resolution of 1/2 chip. From this profile 22, a new set of possible delays

In the new route search results

It is found as the set of delays corresponding to the largest peaks (where they are set to 10) and their half chip neighbors. This is shown in the third profile 23 of FIG. 7, where the ten largest peaks are shown in bold lines and their half chip neighbors are shown in thin lines.

가 가능한 새로운 지연 세트

를 고려하여 갱신되는 상기한 갱신 함수의 결과를 나타낸 것이다. 지연들의 대부분은

및

인 그룹에 속하고, 이들 모두는 기준

을 충족시키며, 따라서 갱신된 값들은 상기한 대응하는 식 및 상기 표에서 언급된 파라미터값들에 따라 계산된다. 몇개의 지연들이

이고

인 그룹에 속하고, 몇개의 다른 지연들은

이고

인 그룹에 속하며, 각각의 경우에, 갱신된 값들은 상기한 바와 같이, 다시 말하면 상기 표에 언급된 파라미터값들을 사용하여 계산된다. 이제 시간 지연들의 합집합

에 대한 전력값이 얻어진다.The lower profile 24 of FIG. 7 shows the previous monitored delay set.

Delay set available

It shows the result of the above update function to be updated in consideration of. Most of the delays

And

Belonging to a group of people, all of which are

The updated values are thus calculated according to the corresponding equations mentioned above and the parameter values mentioned in the table above. Some delays

ego

Belonging to the in group, and some other delays

ego

Belonging to the phosphorus group, in each case, the updated values are calculated using the parameter values mentioned in the above table, in other words, as described above. Now union of time delays

The power value for is obtained.

에 대한 갱신된 전력값들이 도 8의 상부 프로파일에 반복되고 있으며, 지연 절단 및 선택 함수가 이제 이들 지연에 적용될 수 있다. 상기 표에서 암시된 바와 같이, 파라미터

및

는 0으로 설정되고, 따라서 이들 문턱값이 적용되지 않는다. 다수의 피크(상기한 바와 같이,

)가 이어서 가장 큰 전력값을 갖는 지연을 선택하고 새로 발견된 피크에서

(즉, 1 칩)보다 엄밀하게 더 작은 거리 내의 모든 지연들을 제거함으로써 선택된다. 나머지 지연들 중에서, 가장 큰 전력값을 갖는 지연이 이어서 선택되고, 새로 발견된 피크에서

보다 엄밀하게 더 작은 거리 내의 모든 지연들이 제거된다. 이 프로세스는 모든 지연들이 선택되거나 제거될 때까지 또는 이 예에서와 같이

개의 지연들이 선택될 때까지 계속된다. 시간 지연들의 결과 세트는 도 8의 두번째 프로파일(25)에 나타낸 바와 같은

이다.Union of time delays shown in bottom profile 24 of FIG.

The updated power values for are repeated in the top profile of FIG. 8, and the delay truncation and selection function can now be applied to these delays. As implied in the table above,

And

Is set to 0, so these thresholds do not apply. Multiple peaks (as described above,

) Then selects the delay with the highest power value and selects

(I.e. 1 chip) is chosen by eliminating all delays within a strictly smaller distance. Of the remaining delays, the delay with the largest power value is then selected and at the newly found peak

More strictly all delays within a smaller distance are eliminated. This process continues until all delays are selected or removed or as in this example.

It continues until the two delays are selected. The result set of time delays is as shown in the second profile 25 of FIG. 8.

to be.

및 이들의 대응하는 전력값

는 이제 그 세트 내의 각각의 지연의 1/2 칩 이웃들과 함께 세트

가 된다. 세트

의 전력값은 굵은 선으로 나타내어져 있고, 이들의 1/2 칩 이웃들은 가는 선으로 나타내어져 있다. 모니터링된 시간 지연들의 새로운 (갱신된) 세트가 이전의 세트와 그다지 다르지 않다는 것을 알 수 있으며, 이는 상기한 바와 같이, 지연이 모니터링된 세트의 일부인 경우 갱신 함수가 그 지연을 유지하는 데 바이어스를 갖는다는 것을 나타낸다.Finally, as shown in the lower profile 26 of FIG. 8, a new set of monitored time delays

And their corresponding power values

Is now set with half chip neighbors of each delay in the set

Becomes set

The power values of are represented by bold lines and their half-chip neighbors are represented by thin lines. It can be seen that the new (updated) set of monitored time delays is not very different from the previous set, as described above, where the update function has a bias in maintaining that delay if the delay is part of the monitored set. Indicates.

In step 105, Received Signal Code Power (RSCP) and Path Finder window positions are updated. The RSCP sample value is given by the sum of the path finder output powers for the time delays associated with the propagation channel delays. There are different ways of estimating RSCP, and one method may be to apply a delay selection function to appropriately selected thresholds to obtain time delays used in summation.

이다. 이 함수의 출력들은 기껏해야

개의 지연이다. 이 함수에 의해 사용되는 파라미터들은 우리가 선택하고자 하는 지연들의 최대 수

, 지연들을 선택하기 위한 문턱값

및

, 모든 지연들이 이로부터 선택되어야만 하는 시간 윈도우

(

인 경우, 지연들이 어떤 시간 윈도우 내에 들어갈 필요가 없음), 및 셀의 첫번째 경로의 시간 지연

이다.The delay selection function is a function of selecting a subset containing the largest power value given a series of delays from the cell. Inputs to this function are given a number of delays, their power values, and noise levels

to be. The output of this function is at most

Delays. The parameters used by this function are the maximum number of delays we want to select

Threshold for selecting delays

And

, The time window in which all delays must be selected from

(

Delays do not need to fall within any time window), and the time delay of the first path of the cell

to be.

내에 들어가야 한다는 요건이 있는 경우, 이 함수는 윈도우

밖에 있는 모든 지연을 제거하는 것으로 시작한다.

로 정의된 셀의 첫번째 경로가 구간 밖에 있는 경우, 그의 다른 경로들 전부도 또한 드롭(drop)된다. 이러한 이유는 이러한 셀이 데이터를 수신하는 데 사용되는 셀들의 리스트로부터 가능한 한 곧바로 제거되어야만 하기 때문이다.Delay windows

If there is a requirement to be within, this function

Start by removing all the delays that are out there.

If the first path of a cell defined as is outside the interval, all of its other paths are also dropped. This is because such cells should be removed from the list of cells used to receive the data as soon as possible.

및 노이즈 레벨

의

인 총

까지의 부가적인 지연이 선택된다.

가 음수인 경우, 제1 (전력) 문턱값이 적용되지 않으며,

가 음수인 경우, 제2 (노이즈) 문턱값이 적용되지 않는다.The maximum power value is found, and at least

And noise level

of

Phosphorus gun

An additional delay up to is selected.

Is negative, the first (power) threshold is not applied,

If is negative, the second (noise) threshold is not applied.

The placement of the path finder window can be done in a number of known ways. One way is to bring the center of the window to the filtered center of gravity. Once the new path finder window is selected, we need to remove any delay from the monitored delay profile that is no longer in the new path finder window.

Having performed the above processing steps performed immediately after the completion of the path search, it is now checked whether there is a request for the measurement to be calculated in steps 106 and 108 and / or a request for a new delay value to be selected for the RAKE.

라고도 하는, 필터링된 RSSI에 걸쳐 평균된 RSCP가 계산된다. 이들 계산은 단계(107)에서 수행된다.If a request for the calculation of the measurement is detected in step 106 (in this case, every T _measurement frame, as described above), RSCP samples over the measurement period are averaged. Filtering is not recommended because there are very few samples (typically 1-5). This is done for all cells that do not take measurements. In addition, the filtered RSSI,

Also referred to as RSCP, which is averaged over the filtered RSSI. These calculations are performed in step 107.

Similarly, if a request for selecting new delays for RAKE is detected in step 108 (in this case, every T _{delay selection} frame, as described above), the functions of step 109 are performed. . In this step, it is determined which fingers to use in the RAKE to despread the data on a given set of physical channel. As shown in FIG. 9, step 109 includes three steps 201-203 described below. The functions of step 109 are also illustrated in the delay profile shown in FIG.

및 그의 연관된 전력값들

에 적용된다. 여기서, 우리는 우리가 전파 채널 지연을 알아내고자 하는 물리적 채널을 전송하는 모든 셀 c를 고려한다.First, in step 201, as shown in the upper profile 31 of FIG. 10, the delay interpolation function is a set of time delays.

And its associated power values

Applies to Here, we consider every cell c that transmits the physical channel we want to find out the propagation channel delay.

The delay interpolation function is a function that interpolates between delays using a quadratic approximation polynomial whenever possible, given a series of delays. Input to this function is a given number of delays and their power values. The time delay is in units of quarter chips and has a minimum spacing of half chips. The outputs of this function are a series of interpolated delays and their corresponding power values.

The delay with the largest power value is selected, which is tagged as peak 'P', and if present, its half chip neighbors are tagged as 'N'. The next largest power value is then selected from the untagged delay set, which is tagged as peak 'P', and if present, its half chip neighbors are tagged as 'N'. This procedure is repeated until all delays are tagged. This is shown in the upper profile of FIG. 10.

All delays tagged as peak 'P' are passed. If the peak has exactly two neighbors, polynomial interpolation is used to calculate the power values one quarter chip away from the peak. Polynomial coefficients are derived from this peak and its two neighbors. In other words, n is called the time position of the peak, and the unit is 1/4 chip. The neighbors then have time positions n-2 and n + 2. Let y ₁ be the power value for the peak and y ₀ , y ₂ are the power values for the neighbors. Let p (x) be a second order polynomial that satisfies p (n-2) = y ₀ , p (n) = y ₁ and p (n + 2) = y ₂ . The Lagrange form of the interpolation polynomial is given by

Assume that delays one quarter chip away from the peak have the following values.

On the other hand, if the peak is smaller than two neighbors, no interpolated value for the quarter chip delay is calculated on both sides of the peak.

및

이라고 한다. 이것은 도 10의 두번째 프로파일(32)에 도시되어 있으며, 여기서 원래의 전력값은 굵은 선으로 도시되어 있고, 보간된 값은 가는 선으로 도시되어 있다.The output of this function

And

It is called. This is shown in the second profile 32 of FIG. 10 where the original power values are shown in bold lines and the interpolated values are shown in thin lines.

및 전력값

에 적용된다.Then, in step 202, the delay truncation and selection function is a set of time delays.

And power value

Applies to

이다. 이 함수의 출력들은 서로로부터 적어도

떨어져 있는 기껏해야

개의 지연들이다. 이 함수에 의해 사용되는 파라미터들은 우리가 선택하고자 하는 지연들의 최대 수

, 지연들을 선택하기 위한 문턱값

및

, 모든 지연들이 이로부터 선택되어야만 하는 시간 윈도우

(

인 경우, 지연들이 어떤 시간 윈도우 내에 들어가야만 할 필요가 없음), 지연들 간의 최소 간격

(

의 단위는 1/4 칩으로 되어 있음), 셀의 첫번째 경로의 시간 지연

, 및 1로 설정될 때, 선택된 지연들을 가능한 한 균일한 간격으로, 즉 고정된 격자로 떨어져 있게 하려는 파라미터

이다. 파라미터

는 또한 2로 설정될 수 있으며, 이 경우에 이는 모든 지연 시간 차이를

칩의 정수배가 되게 만든다. 이 상황에서, 파라미터

는 일반적으로 1로 설정된다.The delay truncation and selection function is a function of removing time delays associated with weak power values so that, given a series of delays for a cell, there is a given minimum interval between the delays, with a delay corresponding to the strongest power values. The subset of these is selected. Inputs to this function are given a number of delays, their power values, and noise levels

to be. The outputs of this function are at least

At most away

Delays. The parameters used by this function are the maximum number of delays we want to select

Threshold for selecting delays

And

, The time window in which all delays must be selected from

(

Delays do not need to fall within any time window), the minimum interval between delays

(

Is a quarter chip), the time delay of the cell's first path

When set to, and 1, the parameter by which the selected delays are to be spaced at as evenly as possible, i.

to be. parameter

Can also be set to 2, which in this case is the difference

To be an integer multiple of the chip. In this situation, the parameter

Is generally set to one.

및 전력값

에 적용될 수 있다.In this situation, the delay truncation and selection function is a time delay set with the given parameters as

And power value

Can be applied to

parameter A reasonable range of values Examples of reasonable values

4

5 to 10 5

0 to 0.1 0.03

0 to 0.1 0.0015 (-28 dB)

If this is required by the 3GPP specification or due to hardware limitations

0 or 1 One

이 RSSI_filt에 의해 주어지는 것으로 한다.Noise level

It is assumed that this RSSI _filt is given.

내에 들어가야만 한다는 요건이 있는 경우, 이 함수는 윈도우

밖에 있는 모든 지연들을 제거하는 것으로 시작한다. 셀의 첫번째 경로

가 구간 밖에 있는 경우, 모든 그의 다른 경로들도 역시 드롭된다. 이러한 이유는 이러한 셀이 데이터를 수신하는 데 사용되는 셀들의 리스트로부터 가능한 한 곧바로 제거되어야만 하기 때문이다.

로 정의된 셀의 첫번째 경로가 구간의 밖에 있는 경우, 이 프로세스는 이하의 단계로 진행하지 않으며, 비어있는 지연 세트가 출력된다. Delays windows

If there is a requirement to be inside the function, this function

Start by removing all the delays that are out there. Cell's first path

If is outside the interval, all its other paths are also dropped. This is because such cells should be removed from the list of cells used to receive the data as soon as possible.

If the first path of the cell defined by is outside the interval, the process does not proceed to the following steps, and an empty delay set is output.

및 노이즈 레벨

의

인 지연이 선택된다.

가 음수인 경우, 제1 (전력) 문턱값이 적용되지 않으며,

가 음수인 경우, 제2 (노이즈) 문턱값이 적용되지 않는다. 도 10에 도시된 예에서, 모든 전력값들이 상기한 파라미터 값들에 의해 정의되는 문턱값들보다 높고, 따라서 모든 지연들이 선택된다.At least the maximum power value

And noise level

of

Delay is selected.

Is negative, the first (power) threshold is not applied,

If is negative, the second (noise) threshold is not applied. In the example shown in FIG. 10, all power values are higher than the thresholds defined by the parameter values described above, so all delays are selected.

가 1로 설정된 경우(여기에서 일반적으로 그러함)에 행해지는데, 그 이유는 이 상황에서 고정된 격자가 유익할 수 있기 때문이다. 상기에서 이제 막 선택된 지연 세트의 경우,

에 의해 주어지는 가장 큰 전력값을 갖는 시간 지연이 선택되고, 이는 'P'로서 태깅되며, 지연

(1/4 칩 분해능을 다루고 있는 경우

의 양측에서 6임)를 제외한,지연

및

로부터

보다 엄밀하게 더 작은 거리 내의 지연들이 추가적인 고려로부터 제거된다.

보다 엄밀하게 더 작은 거리 내의 지연들을 제거하는 것은 잠재적인 강한 측엽(strong side lobe)을 소거하기 위해 행해진다. 그 다음에,

가 이상에서 전력 및 노이즈 문턱값보다 높은 것으로 선택된 지연들의 일부인지가 검사된다. '예'인 경우, 이는 'P'로서 태깅되고, 지연

를 제외하고,

로부터

보다 엄밀하게 더 작은 거리 내의 지연들과 함께, 이는 추가적인 고려로부터 제거된다. 이 절차는 어떤 양의 정수 n에 대해,

이 선택된 지연들의 일부가 아닐 때까지 반복된다. 이어서 전체적인 방식이

의 좌측에 있는 지연들에 대해 반복된다.Less than

Is set to 1 (as is generally the case here), because a fixed grating may be beneficial in this situation. For the delay set just selected above,

The time delay with the largest power value given by is selected, which is tagged as 'P' and the delay

(When dealing with 1/4 chip resolution

Delay, except for 6) on both sides of

And

from

Delays in more strictly smaller distances are eliminated from further consideration.

Eliminating delays within more strictly smaller distances is done to eliminate the potential strong side lobe. Then,

Is checked if it is part of the delays selected to be higher than the power and noise threshold above. If yes, it is tagged as 'P' and delayed

except,

from

With delays in more strictly smaller distances, this is eliminated from further consideration. This procedure works for any positive integer n,

This is repeated until it is not part of the selected delays. Then the whole way

Repeated for the delays to the left of.

에 의해 주어지는 가장 큰 전력값을 갖는 시간 지연을 선택하고, 이를 "P"로서 태깅하고,

로부터

보다 엄밀하게 더 작은 거리 내의 지연들을 추가적인 고려로부터 제거하며, 그 후에

이 미리 선택된 지연들의 일부인지를 검사하고, '예'인 경우, 이들을 'P'로서 태깅하고,

으로부터

보다 엄밀하게 더 작은 거리 내의 지연들을 추가적인 고려로부터 제거한다.For the remaining delays, this procedure is repeated, i.e.

Select the time delay with the largest power value given by and tag it as "P",

from

Delays within a more strictly smaller distance are removed from further consideration, and then

Check if these are some of the preselected delays, if yes, tag them as 'P',

From

More precisely, delays within smaller distances are eliminated from further consideration.

의 거리 내의 지연들이 제거된다. 그렇지만, 예로서, 이 방법은 또한

의 거리 내의 지연만이 제거되도록 수정하여 적용될 수 있다.In the operations just described, from the delay of the problem

Delays within the distance of are eliminated. However, as an example, this method also

Only a delay within the distance of may be modified to be applied.

개의 지연들이 'P'로서 태깅될 때 또는 'P'로서 태깅하기 위한 가능한 후보 세트를 소진하였을 때 완료된다. 출력은 'P'로서 태깅된 지연 세트에 의해 제공된다. 출력은

및

라고도 할 수 있다.

Delays are completed when tagged as 'P' or when the available candidate set for tagging as 'P' is exhausted. The output is provided by a delay set tagged as 'P'. The output is

And

It can also be called.

가 0으로 설정되고, 이하의 동작들이 그 대신에 행해진다. 이제 막 선택된 지연 세트의 경우, 가장 큰 전력값을 갖는 지연이 선택되고, 그것이 피크 'P'로서 태깅되며, 새로 발견된 피크로부터

보다 엄밀하게 더 작은 거리 내의 모든 지연이 제거된다. 나머지 지연들, 즉 태깅되지도 제거되지도 않은 지연들 중에서, 가장 큰 전력값을 갖는 지연이 선택되고, 그것이 피크 'P'로서 태깅된다. 다시 말하면, 새로 발견된 피크로부터

보다 엄밀하게 더 작은 거리 내의 모든 지연들이 제거된다. 이 프로세스는 모든 지연들이 태깅 또는 제거될 때까지 또는

개의 지연들이 태깅될 때까지 계속된다. 출력 지연 세트는 'P'로서 태깅된 지연들에 의해 주어진다.However, if a fixed grid is not desired with respect to delay values for RAKE,

Is set to 0, and the following operations are performed instead. For the delay set just selected, the delay with the largest power value is selected, it is tagged as peak 'P', and from the newly found peak

More strictly all delays within smaller distances are eliminated. Of the remaining delays, i.e., those that are neither tagged nor eliminated, the delay with the largest power value is selected and it is tagged as peak 'P'. In other words, from the newly discovered peak

More strictly all delays within a smaller distance are eliminated. This process will continue until all delays are tagged or removed.

It continues until t delays are tagged. The output delay set is given by the delays tagged as 'P'.

는 또한 2로도 설정될 수 있다.

가 2로 설정되면, 이하의 것들이 행해진다. 상기에서 이제 막 선택된 지연 세트에 대해,

으로 주어지는 가장 큰 전력값을 갖는 시간 지연이 선택되고 'P'로서 태깅되며,

(단, n은 모든 가능한 정수)에 있는 것들을 제외한 모든 지연들이 추가적인 고려로부터 제거된다. 지금까지 단지 하나의 지연만이 'P'로서 태깅된 것에 유의한다. 나머지 지연들에 대해, 가장 큰 전력값을 갖는 시간 지연이 선택되고, 'P'로서 태깅되며, 추가적인 고려로부터 제거된다. 이 절차는 이어서

개의 지연들이 'P'로서 태깅될 때까지 또는 'P'로서 태깅하기 위해 가능한 후보 세트를 소진하였을 때 반복된다. 출력은 'P'로서 태깅된 지연 세트에 의해 주어진다.As mentioned above,

Can also be set to two.

If is set to 2, the followings are done. For the delay set just selected above,

The time delay with the largest power value given by is selected and tagged as 'P',

All delays except those in which n is all possible integers are eliminated from further consideration. Note that so far only one delay has been tagged as 'P'. For the remaining delays, the time delay with the largest power value is selected, tagged as 'P', and removed from further consideration. This procedure is followed

Delays are repeated until t are tagged as 'P' or when the available candidate set for tagging as 'P' is exhausted. The output is given by a delay set tagged as 'P'.

을 갖는 P₁으로서 선택되고, 지연

를 제외하고

에서

보다 엄밀하게 더 작은 거리 내의 지연들이 추가적인 고려로부터 제거된다.

이 1칩인 경우,

에 가장 가까운 4개의 지연만이 제거된다. 이것은 점선으로 나타내어져 있다. 값

이 이 경우에 선택된 지연들의 일부가 아닌 경우, 나머지 지연들 중에서 가장 큰 전력값을 갖는 시간 지연이 이어서 대응하는 지연값

를 갖는 P₂로서 선택되고,

를 제외하고

에서

보다 엄밀하게 더 작은 거리 내의 지연들(이 경우에, 6개의 지연)이 제거되며, 이는 도 10의 네번째 프로파일(34)에서 점선으로 나타내어져 있다. 지연

이 선택된 지연들의 일부가 아니지만, 지연

은 그의 일부이며, 따라서 후자의 값이 또한 P로서 태깅되고, 지연

를 제외하고 그로부터

보다 엄밀하게 더 작은 거리 내의 지연들이 제거된다. 이 프로세스는 5개(즉, N_selected)의 지연이 P로서 태깅될 때까지 계속된다. 이것은 도 10의 5번째 프로파일(35)에 도시되어 있다. 이들 5개의 지연값들의 세트가 따라서 세트

이며, 이는 고려 중인 셀에 대한 RAKE에 사용될 지연 세트이다. 이 지연 세트는 도 10의 아래쪽 프로파일(36)에 도시되어 있다.The above process is also shown in FIG. 10. In the third profile 33, the peak with the highest power value corresponds to the delay value.

Is selected as P ₁ with delay

except

in

Delays in more strictly smaller distances are eliminated from further consideration.

Is 1 chip,

Only the four delays closest to are eliminated. This is indicated by the dotted line. value

If it is not part of the selected delays in this case, the time delay with the largest power value among the remaining delays is then followed by the corresponding delay value.

Selected from P ₂ having

except

in

Delays within a more strictly smaller distance (in this case six delays) are eliminated, which is indicated by the dashed line in the fourth profile 34 of FIG. delay

This is not part of the selected delays, but the delay

Is part of it, so the latter value is also tagged as P, and delayed

Except from that

More precisely, delays within smaller distances are eliminated. This process continues until five delays (ie, N _selected ) are tagged as P. This is shown in the fifth profile 35 of FIG. 10. The set of these five delay values is thus set

This is the delay set to be used for the RAKE for the cell under consideration. This delay set is shown in the lower profile 36 of FIG.

If the physical channel is sent from only one cell, flow proceeds to step 203. In step 203, a multi-cell delay selection function is applied to the union of truncated time delays coming from cells transmitting the physical channel of interest.

이다.The multi-cell delay selection function is a function of selecting a subset of delays from the cells containing the largest power value, given a set of delays per cell output from the delay selection function (if not completed). The inputs to this function are a given number of delays from several cells and their power values. The output of this function is at most N _selected delays. The parameters used by this function are the maximum number of delays N _selected , and the threshold for selecting delays.

to be.

In the multi-cell delay selection function, the following parameter settings can be used.

parameter A reasonable range of values Examples of reasonable values

0 to 0.4 0.3 N _selected 3 to 10 5

In the following, it is assumed that the cells are numbered according to the value of the maximum power value of the cells, ie cell 1 contains the highest power value, cell 2 contains the second highest power value, and so on. to be. It should be noted that for a given delay, there may be several power values if the delays from multiple cells match.

%인 경우, 가장 약한 경로가 세트 S₁로부터 제거되고, 이는 셀 2로부터의 가장 강한 경로로 대체된다. 이것이 행해지는 이유는 셀 2가 셀 1로부터의 경로들과 전혀 상관되어 있지 않으며 따라서 그의 기여가 중요하다는 것을 알고 있기 때문이다.Example I. The N _selected largest power values are from cell 1 and this set is called S ₁ . The path from cell 2 is 100 of the maximum power value for cell 1

If%, the weakest path is removed from set S ₁ , which is replaced by the strongest path from cell 2. This is done because cell 2 has no correlation with the paths from cell 1 and therefore knows its contribution is important.

%인 경우, 가장 약한 경로가 세트 S₁₂로부터 제거되고, 그것이 셀 3으로부터의 가장 강한 경로로 대체된다. 가장 약한 경로를 제거하는 것이 셀 2가 더 이상 세트 S₁₂에 포함되지 않는다는 것을 의미하는 경우, 우리는 그 대신에 셀 1로부터의 가장 약한 경로를 제거한다. 예를 들어, N_selected이 6이고 셀 1이 5개의 가장 강한 경로로 기여하는 경우, 우리는 셀 1으로부터의 가장 약한 경로를 제거하고, 그것을 셀 3으로부터의 가장 강한 경로로 대체한다. 모든 다른 셀들은 무시된다.Case II. The N _selected largest power values are from cells 1 and 2 and this set is called S ₁₂ . The path from cell 3 is 100 of the maximum power value from cell 1

If%, the weakest path is removed from set S ₁₂ and it is replaced with the strongest path from cell 3. If removing the weakest path means that cell 2 is no longer included in set S ₁₂ , we instead remove the weakest path from cell 1. For example, if N _selected is 6 and cell 1 contributes to the five strongest paths, we remove the weakest path from cell 1 and replace it with the strongest path from cell 3. All other cells are ignored.

This procedure can be easily generalized to more cells. While at most one delay has been replaced by a weaker delay from another cell, this should also be generalized to include replacing some delays from multiple cells, but at most one delay per newly introduced cell. Can be.

Note that all other physical channels receive their signals from only one cell, except for the dedicated physical channel (DPCH).

This procedure can also be used in so-called "generalized" RAKE (G-RAKE) receivers, which typically use a combined weight that is a function of noise covariance, which includes information about channel coefficients and interfering signals. The join weight is used to combine the despread values at combiner 16. The G-RAKE receiver differs from the conventional RAKE receiver in that it considers delays in addition to corresponding to the peak of the desired signal as described above. These other delays are generally chosen to provide information about the interference so that the receiver can suppress the interference.

In a conventional RAKE receiver, the fingers are selected such that the maximum amount of energy of the desired signal is collected, for example, as described above. However, in a G-RAKE receiver, finger selection criteria can also collect interference signal information such that a desired amount of interference suppression can be achieved. G-RAKE can be considered as a kind of equalizer that whitens inter-cell interference as well as mitigates inter-symbol interference (ISI).

Thus, if the receiver is a G-RAKE receiver, flow proceeds to step 204 where an ISI delay selection function is applied. Its purpose is to select additional fingers used for G-RAKE. Additional fingers do not need to match the peak delays.

및 그의 전력값들

이다. 이 함수의 출력들은 전파 채널의 공분산 행렬을 추정할 때 사용되는 추가 지연들의 세트

이다. 이 함수에 의해 사용되는 파라미터는 다수의(N_E개의) 추가 지연들 및 윈도우

(추가의 지연들이 이 윈도우 내에 포함되어 있어야 함)(전파 채널 지연들이 이 윈도우에 포함되어 있는 것으로 가정됨), 및 지연들 간의 최소 간격

(1/4 칩의 단위로 되어 있음)이다.The ISI selection function is a function of selecting a number of additional fingers to be used with the peak when despreading data, given a set of propagation channel peaks and their power values. Input to this function is a time delay for the propagation channel.

And its power values

to be. The outputs of this function are a set of additional delays used to estimate the covariance matrix of the propagation channel.

to be. The parameters used by this function are a number of (N _E ) additional delays and windows

(Additional delays must be included in this window) (assuming propagation channel delays are included in this window), and the minimum interval between delays

(In units of quarter chips).

내의 지연들 간의 모든 거리가 계산되고 분류된다. 증가하는 순서

(단,

는 거리의 총 수임)로 분류된 거리들의 세트를 호출한다.

는 공집합으로 설정된다. 그 다음 지연들이 세트

에 추가된다. 언제라도,

내의 지연들의 총수가 N_E와 같을 때, 완료되고 임의의 추가 처리를 중단한다.

내의 가장 큰 전력값이 선택되고,

를 그의 대응하는 시간 지연으로 한다.

All distances between delays within are calculated and classified. Increasing order

(only,

Is the total number of distances).

Is set to the empty set. Then delays set

Is added to whenever,

When the total number of delays in is equal to N _E , it completes and stops any further processing.

The largest power value in the

As its corresponding time delay.

이 윈도우

내에 있는지와,(i)

This window

Within,

이 시간 지연 세트

로부터 적어도

개의 1/4 칩 떨어져 있는지를 검사한다.(ii)

This time delay set

From at least

Check to see if you have 1/4 chips apart.

이 추가 지연들의 세트

(이제 하나의 지연으로 이루어져 있음)에 추가된다. (i) 및 (ii)에서의 검사는 잠재적인 추가 지연

에 대해 반복되고, 그것이 통과하는 경우 세트

에 추가된다.In such a case, delay

Set of these additional delays

(Which now consists of one delay). The tests in (i) and (ii) may have potential additional delays

Iterate over and set if it passes

Is added to

이라고 한다. 이전과 마찬가지로, 잠재적인 추가 지연

이 상기 기준 (i) 및 (ii)를 통과하는지가 검사되고, 통과하는 경우 세트

에 추가된다. 이 절차는 잠재적인 추가 지연

에 대해 반복된다. 이어서, 이 절차는 세번째로 가장 큰 전파 채널 전력값과 연관된 시간 지연에 대해 반복된다. 이 프로세스는 모든 전파 채널 시간 지연들을 순회할 때까지 계속된다.Then, the propagation channel time delay associated with the second largest power value is considered, which

It is called. As before, potential additional delays

Is checked if it passes the above criteria (i) and (ii), and if it passes

Is added to This procedure is a potential additional delay

Is repeated for. This procedure is then repeated for the time delay associated with the third largest propagation channel power value. This process continues until it traverses all propagation channel time delays.

이 전파 채널 시간 지연에 대한 오프셋으로서 사용되었다. 전체적인 절차가 이제부터 거리

에 대해 반복된다, 즉 잠재적인 추가 지연

에 대해 (i) 및 (ii)를 검사하며, 여기서

는 이전과 같이 가장 큰 전력값과 연관된 시간 지연이고, 모든 전파 채널 시간 지연을 순회할 때까지 계속된다. 이 절차는 이어서 모든 거리에 대해 다 할 때까지 거리

등에 대해 반복된다. 서두에서 언급한 바와 같이, 이 절차는 세트

가 N_E개의 지연을 포함할 때 언제라도 중단된다. 유의할 점은 파라미터 선택에 따라 N_E개의 추가 지연으로 항상 끝나는 것이 아닐 수도 있다는 것이다.So far, the same distance

This was used as an offset to the propagation channel time delay. Distance from now on the whole procedure

Is repeated for, i.e., potential additional delay

For (i) and (ii), where

Is the time delay associated with the largest power value as before, and continues until it traverses all propagation channel time delays. This procedure is followed by the distance until all distances are done.

And so on. As mentioned at the outset, this procedure

Is stopped any time when N contains N _E delays. Note that depending on the parameter selection, it may not always end with N _E additional delays.

Finally, if the route search initiated in step 101 has not yet completed, the process returns to step 101 and waits for it to complete in step 110 before repeating the above steps.

While the preferred embodiment of the invention has been described and illustrated, the invention is not limited thereto and may be implemented in other ways within the scope of the subject matter defined in the following claims.

Claims (29)

A method of receiving digital data symbols from at least two transmitters over a transmission channel of a communication network, the method comprising: Individual multipath components of the transmitted data symbols are received with individual delays, and the received signals are processed by a RAKE unit 12 having multiple fingers, the method being a series of received pilot signals. Providing a delay profile for each transmitter from the plurality of transmitters, wherein the delay profile is generated from the results of at least one path search and for each of the first number of delay values. Indicates the magnitude of the received signal level, The method, Associating a counter with each of the transmitters, Incrementing the counter associated with the given transmitter by one each time a digital data symbol of a frame is received from a given transmitter until the counter reaches a maximum counter value N _C , Requesting a path search to be performed for the given transmitter when the associated counter reaches a first predefined value (T _{delay selection} ), List route search requests to a first-in-first-out queue; Activating path search in the order in which path searches are placed in the FIFO queue, and Decrementing the counter associated with the transmitter by a second predefined value Δn _c when the path search for the transmitter is activated Method further comprising a. The method of claim 1, wherein Calculating, by interpolation, an estimated magnitude of a received signal level for a second number of delay values located between at least some of the first number of delay values, Providing a combined delay profile 32 by combining magnitudes of received signal levels for the first number of delay values and the second number of delay values, Determining delay values for the detected peaks in the combined delay profile, Selecting a plurality of peak delay values P ₁ , P ₂ , P from among the peak delay values determined for the combined delay profile, wherein the selected peak delay values are the largest detected in the combined delay profile. At least a delay representing the peak, and Providing at least some of the selected peak delay values to the RAKE unit 12 and assigning each provided peak delay value to a finger of the RAKE unit 12 Method further comprising a. 3. The method of claim 2, wherein at least some of the first number of delay values are equidistantly spaced. 4. The method of claim 3, wherein each of said second number of delay values is located midway between two neighboring delay values of said first number of delay values. 5. A method according to any one of claims 2 to 4, wherein said calculating the estimated magnitude of said second number of delay values is performed using polynomial interpolation. The method of any one of claims 2 to 5, wherein the step of selecting a plurality of peak delay values, Selecting a delay value representing the largest peak detected in the combined delay profile, Excluding from consideration all delay values within a distance strictly less than a predefined minimum interval of said just selected delay value, and Among the remaining delay values, the delay value representing the largest peak detected is repeatedly selected, and a given number of delay values are selected or until all delay values of the combined delay profile are selected or excluded from consideration. Excluding from the consideration all delay values within a distance strictly smaller than the predefined minimum interval of the just selected delay value. Method comprising a. The method of any one of claims 2 to 5, wherein the step of selecting a plurality of peak delay values, Preselecting all delay values of the combined delay profile that represent magnitudes of the received signal level higher than a predefined threshold, Selecting a delay value representing the largest peak among the preselected delay values, A delay value within a distance that is strictly less than twice the predetermined minimum interval of the delay value that has just been selected and the delay value that is just selected, except for delay values located at the predefined minimum interval from the delay value that is just selected Excluding them from consideration, If a delay value located at the predefined minimum interval from a previously selected delay value belongs to the preselected delay values, this value is repeatedly selected and is located at the predefined minimum interval from the just selected delay value. Excluding, from the considerations, delay values within a distance strictly less than twice the predefined minimum interval of the just-selected delay value and the delay value just selected, and Repeating these steps for the remaining preselected delay values until a given number of delay values are selected or until all preselected delay values are selected or excluded from consideration Method comprising a. The method of claim 2, wherein the method comprises: Generating a combined set of peak delay values from the selected peak delay values for each transmitter, Generating a reduced set of peak delay values by selecting a plurality of largest peak delay values from the combined set of peak delay values, The reduced peak delay if no peak delay from a given transmitter is included in the reduced set of peak delay values and at least one peak delay from the given transmitter indicates a peak that is higher than a predefined threshold Generating a modified set of peak delay values by replacing the peak delay value of the weakest peak from the value set with the peak delay value of the largest peak from the given transmitter, and Providing the modified set of peak delay values to the RAKE unit 12 and assigning each peak delay value of the modified set to a finger of the RAKE unit 12. Method further comprising a. 9. A method according to any one of claims 2 to 8, characterized in that the active path search for the transmitter provides a new search delay profile (22) for that transmitter. The method of claim 9, wherein Extracting the closest neighbor delay values of these peaks from the plurality of largest peak delays and the new search delay profile for the transmitter, and By obtaining a updated delay profile 24 by adding a percentage of the difference between the previously calculated magnitude and the corresponding magnitude from the new search delay profile to the previously calculated magnitude, Of course, for each delay value represented in the extracted delay values, updating the previous delay profile 21 provided for that transmitter by calculating the updated magnitude of the received signal level for that delay value. Method further comprising a. 11. The method of claim 10, wherein the percentage is dependent on comparing the magnitude from the new search delay profile with the previously calculated magnitude. The method of claim 10 or 11, wherein the method Selecting a delay value representing the largest peak detected in the updated delay profile 24, Excluding from the consideration all delay values within a distance strictly less than the predefined minimum interval of the just selected delay value, The delay value representing the largest peak detected among the remaining delay values is repeatedly selected and all delay values of the updated delay profile 24 are selected or excluded from consideration until a given number of delay values are selected. Until, excluding from consideration all delay values within a distance strictly less than the predefined minimum interval of the just selected delay value, and Providing a monitored delay profile 26 comprising the selected delay values and their nearest neighbor delay values among the updated delay profiles. Method further comprising a. The method of claim 12, wherein Each time a digital data symbol of a predetermined number of frames is received, providing a combined delay profile and selecting a plurality of peak delay values from among the peaks of the combined delay profile; , The monitored delay profile is used as a delay profile provided for a transmitter. A receiver (10) for receiving digital data symbols from at least two transmitters through a transmission channel of a communication network, Each multipath component of the transmitted data symbol is received with an individual delay, the receiver comprising a RAKE unit 12 having a plurality of fingers for processing the received signals, the receiver being a series of Provide a delay profile for each transmitter from received pilot signals of the delay profile, wherein the delay profile is generated from the results of at least one path search and is a first number of delay values. Represents the magnitude of the received signal level for each of The receiver, Associate a counter with each of the transmitters, Increment the counter associated with the given transmitter by one each time a digital data symbol of a frame is received from a given transmitter until the counter reaches a maximum counter value N _C , Request a path search to be performed for the given transmitter when the associated counter reaches a first predefined value (T _{delay selection} ), List route search requests to a first-in-first-out queue Activate path search in the order in which path searches are placed in the FIFO queue, To decrease the counter associated with the transmitter by a second predefined value Δn _c when the path search for the transmitter is activated Receiver, characterized in that further configured. The method of claim 14, wherein the receiver, Calculate, by interpolation, an estimated magnitude of a received signal level for a second number of delay values located between at least some of the first number of delay values, Providing a combined delay profile 32 by combining magnitudes of received signal levels for the first number of delay values and the second number of delay values, Determine delay values for the detected peaks in the combined delay profile, Select a plurality of peak delay values P ₁ , P ₂ , P from among the peak delay values determined for the combined delay profile, wherein the selected peak delay values are the largest peak detected in the combined delay profile Contains at least a delay value indicating-, Provide at least some of the selected peak delay values to the RAKE unit 12 and assign each provided peak delay value to a finger of the RAKE unit 12. Receiver, characterized in that further configured. 16. The receiver of claim 15, wherein the receiver is configured to provide a delay profile (31) for the transmitter such that at least some of the first number of delay values are equidistantly spaced. 17. The receiver of claim 16 wherein the receiver is configured to find each of the second number of delay values in the middle of two neighboring delay values of the first number of delay values. 18. The receiver of any one of claims 15 to 17, wherein the receiver is configured to calculate the estimated magnitudes of the second number of delay values using polynomial interpolation. 19. The receiver of any one of claims 15 to 18, wherein the receiver is Select a delay value representing the largest peak detected in the combined delay profile 32, Excludes from consideration all delay values within a distance strictly less than the predefined minimum interval of the just selected delay value, Among the remaining delay values, the delay value representing the largest peak detected is repeatedly selected, and a given number of delay values are selected or until all delay values of the combined delay profile are selected or excluded from consideration. To exclude from consideration all delay values within a distance that is strictly smaller than the predefined minimum interval of the delay value just selected. And configured to select a plurality of peak delay values. 19. The receiver of any one of claims 15 to 18, wherein the receiver is Preselect all delay values of the combined delay profile that represent magnitudes of the received signal level higher than a predefined threshold, Selecting a delay value representing the largest peak among the preselected delay values, A delay value within a distance that is strictly less than twice the predetermined minimum interval of the delay value that has just been selected and the delay value that is just selected, except for delay values located at the predefined minimum interval from the delay value that is just selected Except in consideration, If a delay value located at the predefined minimum interval from a previously selected delay value belongs to the preselected delay values, this value is repeatedly selected and is located at the predefined minimum interval from the just selected delay value. Excluding the delay values, excluding delay values within a distance strictly less than twice the predefined minimum interval of the just-selected delay value and the delay value just selected, Repeat these steps for the remaining preselected delay values until a given number of delay values have been selected or until all preselected delay values have been selected or excluded from consideration. And configured to select a plurality of peak delay values. The receiver of claim 15, wherein the receiver comprises: Generate a combined set of peak delay values from the peak delay values selected for each transmitter, Generating a reduced set of peak delay values by selecting a plurality of largest peak delay values from the combined set of peak delay values, The reduced peak delay if no peak delay from a given transmitter is included in the reduced set of peak delay values and at least one peak delay from the given transmitter indicates a peak that is higher than a predefined threshold Generating a modified set of peak delay values by replacing the peak delay value of the weakest peak from the value set with the peak delay value of the largest peak from the given transmitter, Provide the modified set of peak delay values to the RAKE unit 12 and assign each peak delay value of the modified set to a finger of the RAKE unit 12. Receiver, characterized in that further configured. 22. A receiver as claimed in any one of claims 15 to 21, wherein the receiver is configured to provide a new search delay profile (22) for the transmitter in response to an activated path search for the transmitter. The method of claim 22, wherein the receiver, Extract the nearest neighbor delay of these peaks from the delay values of the plurality of largest peaks and the new search delay profile for the transmitter, By obtaining a updated delay profile 24 by adding a percentage of the difference between the previously calculated magnitude and the corresponding magnitude from the new search delay profile to the previously calculated magnitude, Of course, for each delay value represented in the extracted delay values, by calculating the updated magnitude of the received signal level for that delay value, the previous delay profile 21 provided for that transmitter is updated. Receiver, characterized in that further configured. 24. The receiver of claim 23 wherein the percentage is dependent on comparing the magnitude from the new search delay profile with the previously calculated magnitude. The method of claim 23 or 24, wherein the receiver, Select a delay value representing the largest peak detected in the updated delay profile 24, Now consider all delays within a distance that is strictly smaller than the predefined minimum interval of the just selected delay value, Among the remaining delay values, a delay value representing the largest peak detected is repeatedly selected and all delay values of the updated delay profile 24 are selected or taken into account until a given number of delay values are selected. Until excluded, except from consideration all delay values within a distance that is strictly smaller than the predefined minimum interval of the just selected delay value, To provide a monitored delay profile 26 comprising the selected delay values and their nearest neighbor delay values among the updated delay profiles. Receiver, characterized in that further configured. The method of claim 25, wherein the receiver, Each time a digital data symbol of a predetermined number of frames is received, provide a combined delay profile and select a plurality of peak delay values from among the peaks of the combined delay profile, To use the monitored delay profile 26 as a delay profile provided for the transmitter. Receiver, characterized in that further configured. 27. The receiver of any one of claims 14-26, wherein the receiver is a WCDMA receiver. 14. A computer program comprising program code means for performing the steps of any of claims 1 to 13 when the computer program is executed on a computer. A computer readable medium storing program code means for performing the method of any one of claims 1 to 13 when the program code means is executed on a computer.

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