JP4888391B2 - Intraframe code diversity - Google Patents

Description

  The present invention relates to mobile radio signal diversity, and more particularly, to encoding downlink and uplink mobile radio data transmitted from a single source in multiple time slots within a frame.

  In a CDMA wireless system, data is transmitted by sending a code sequence every bit or data symbol. Each user is assigned a different code. When a user transmits data on multiple channels, each user channel is assigned a different code. By using separate codes, multiple users can transmit signals in the same frequency band within the same time slot. The code is generally intended to have good cross-correlation properties. Good cross-correlation properties allow the receiver to relate received composite signals containing several codes to separate one or more individually encoded signals from the composite signal Become.

  It is not always possible to obtain good cross-correlation characteristics between selected code groups. Furthermore, multipath within the radio channel can change the cross-correlation characteristics of the signal before it reaches the receiver. Thus, there are certain cases where the cross-correlation between the signals is good, and other cases where the cross-correlation is degraded. Poor cross-correlation can lead to poor radio link performance, increased bursts of data errors, and reduced spectral efficiency of the system.

According to one aspect of the present invention, a method for transmitting data on a link from a first wireless device to a second wireless device using a time slot in a frame, wherein the data is within a frame period. Encoding a unit of user data to be transmitted over a transmission time interval (TTI) with application of forward error correction; and for transmitting the unit of user data to the first wireless device. Assigning a set of code resources, the method comprising: scrambling each code of a first set of channelization codes based on the assigned code resource with a first scrambling code; Generating a set of one and each code of a second set of channelization codes based on the assigned code resource Generating a second set of spreading codes by scrambling with one scrambling code, wherein the first set of channelization codes is different from the second set of channelization codes; Spreading a first portion of the user data to be encoded using a first set of spreading codes; and the user data being encoded using a second set of spreading codes. Spreading the second portion of the user data, and in the first portion of the frame, spreading the first portion of the user data to be encoded from the first wireless device to the second wireless Transmitting the second portion of the user data to be encoded in the second portion of the frame from the first wireless device to the second empty portion. Wherein the step of transmitting device, is provided.

  Certain embodiments of the present invention provide a method in which a time slot includes a first frame portion and a second frame portion. A particular embodiment of the present invention is a method wherein the first frame portion includes a first frame time slot and the second frame portion includes a second frame time slot, wherein the second time slot is the first time slot. A method different from one time slot is provided. Certain embodiments of the present invention provide a method in which the first time slot and the second time slot are adjacent time slots. Certain embodiments of the present invention provide a method wherein the first time slot and the second time slot are time slots separated by at least one time slot period.

  A specific embodiment of the present invention comprises the steps of encoding a third user data portion with a third spreading sequence and encoding a fourth user data portion with a fourth spreading sequence. The fourth spreading sequence is different from the third spreading sequence, and in the first portion of the second frame, the encoded third user data portion is sent from the first wireless device to the second Transmitting to a wireless device, wherein the first portion of the second frame is encoded in the step corresponding to the first portion of the first frame and the second portion of the second frame Transmitting a fourth user data portion from the first wireless device to the second wireless device, wherein the second portion of the second frame corresponds to the second portion of the first frame; A method is further provided. Certain embodiments of the present invention provide a method further comprising the step of performing forward error correction over a plurality of time slots in a frame.

  Certain embodiments of the present invention provide a method further comprising the step of interleaving over a plurality of time slots. Certain embodiments of the present invention provide a method in which the first spreading sequence includes a first scramble code and the second spreading sequence includes a second scramble code different from the first scramble code. . Particular embodiments of the present invention provide that, in the first frame portion, transmitting the encoded first user data portion from the first wireless device to the second wireless device comprises the first midamble. Transmitting the encoded second user data portion from the first wireless device to the second wireless device in the second frame portion, comprising: transmitting a sequence; And transmitting a second midamble sequence separate from the method.

  Certain embodiments of the present invention further comprise determining a first spreading sequence for the first user data portion and determining a second spreading sequence for the second user data portion. I will provide a. Particular embodiments of the present invention provide a method in which the link includes an uplink, the first wireless device includes a mobile wireless device, and the second wireless device includes a base station. Certain embodiments of the present invention provide a method in which the link includes a downlink, the first wireless device includes a base station, and the second wireless device includes a mobile wireless device.

According to another aspect of the present invention, there is provided a code diversity transmitter, and logic for accepting user data, one unit to be transmitted over a transmission time interval within one frame period (TTI) Encoding code configured to apply forward error correction to user data; and logic for assigning a set of code resources for transmission of the unit of user data, the code diversity transmitter Logic for generating a first set of spreading codes by scrambling each code of the first set of channelization codes based on the assigned code resources with a first scramble code, and the assigned code Each code of the second set of channelization codes based on resources Logic for generating a second set of spreading codes by scrambling with a crumble code, the first set of channelization codes is different from the second set of channelization codes, and Using code mapping and distribution logic operable to parse data into a first portion of the user data and a second portion of the user data, and the first set of spreading codes, Operable to spread the first portion of the user data to be encoded and use the second set of spreading codes to spread the second portion of the user data to be encoded And spreading of the user data encoded in the first portion of the frame coupled to the spreading logic. A transmitter operable to transmit the first portion and in the second portion of the frame to transmit the spread second portion of the user data to be encoded. A code diversity transmitter is provided.

  Particular embodiments of the present invention include forward error correction (FEC) logic operable to apply forward error correction to user data, including logic for accepting user data and code mapping and distribution logic FEC logic coupled between and. A particular embodiment of the present invention is a code diversity transmission further comprising logic for interleaving, the logic being coupled between logic for accepting user data and code mapping and distribution logic. Provide a bowl.

  Certain embodiments of the present invention provide a code diversity transmitter in which the first user data portion includes a time slot data block. A particular embodiment of the present invention provides a code diversity transmitter in which the first spreading sequence includes a first scramble code and the second spreading sequence includes a second scramble code different from the first scramble code. I will provide a.

  According to another aspect of the present invention, an apparatus is provided for transmitting data on a link from a first wireless device to a second wireless device over a plurality of time slots in a frame. The apparatus includes means for associating a first user data portion with the first frame portion, means for associating the second user data portion with the second frame portion, and the first user data portion with the first user data portion. Means for encoding with a second spreading sequence, means for encoding a second user data portion with a second spreading sequence, wherein the first spreading sequence is different from the second spreading sequence, Means for transmitting an encoded first user data portion from a first wireless device to a second wireless device in a second frame portion; and a second user encoded in a second frame portion. Means for transmitting the data portion from the first wireless device to the second wireless device.

  Other features and aspects of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example embodiments of the invention. The above description is not intended to limit the scope of the invention. The scope of the invention is defined only by the claims.

  Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings.

  In the following description, reference is made to the accompanying drawings that illustrate several embodiments of the present invention. Other embodiments can be utilized, and mechanical, structural, structural, electrical, and operational changes can be made without departing from the spirit and scope of the present invention. it can. The following detailed description is not to be taken in a limiting sense, and the scope of the embodiments of the present invention is defined by the claims of the issued patent.

  Certain portions of the detailed description that follow are presented in terms of procedures, steps, logic blocks, processing, or other symbolic behavioral representation of data bits that can be performed on computer memory. Procedures, computer-implemented steps, logic blocks, processes, etc., are considered in this specification and claims as a straightforward sequence of steps or instructions that lead to a desired result. A process uses a physical manipulation of physical quantities. Such quantities may take the form of electrical, magnetic or wireless signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. Such signals may optionally be represented as bits, values, elements, symbols, characters, terms, numbers, or the like. Each step can be performed by hardware, software, firmware, or a combination thereof.

  A particular CDMA system selects a spreading code from a predetermined set of values. In certain CDMA systems (such as 3GPP UTRA TDD / FDD systems), the spreading code may be composed of two components (ie, a channelization code component and a scramble code component). For example, in the 3GPP UTRA TDD CDMA system, the spreading code consists of a scramble code and a channelization code. Generally, the system uses a channelization code component that separates multiple users within a time slot of a cell and a scramble code component that distinguishes signals originating from within the cell from signals arriving from other cells. it can.

FIG. 1 shows a model of an uplink TDD CDMA encoding, transmission and reception system. User payload data 110 is provided to spreader 120 as channel data (Ch ₁ ) 115. Spreader 120 also accepts spreading sequence 121 (channelization code C _c1 122 and channelization code C _c1 123). The spreader 120 encodes the user payload data 110 with the spreading sequence 121 by encoding with the channelization code (C _c1 ) 122 and with the cell specific scrambling code (C _s1 ) 123.

Users belonging to the common cell can share the same cell-specific scramble code (C _s1 ) 123. A user belonging to another cell has another cell-specific scrambling code (eg, C _s2 ). The encoded payload data constitutes an encoded sequence 125. The encoded sequence 125 is supplied to a transmitter (xmtr) 130 and transmitted as a sequence 135 via the radio channel 140. Radio channel 140 is configured between user equipment transmitter 130 and base station receiver 150. The received signal is then processed by the base station to separate each user's payload data.

  FIG. 2 shows a time slot burst signal 200 (eg, a time slot burst signal from a TDD CDMA user). The encoded sequence 125 (FIG. 1) is divided into a first payload portion 210 and a second payload portion 220. The time slot burst signal 200 includes a first payload portion 210 that precedes the midamble sequence 230 and a second payload portion 220 that follows. The receiver uses the known midamble sequence 230 to determine the impulse response of the radio channel 140 (FIG. 1). The impulse response helps the receiver 150 in the detection and demodulation process.

  The characteristics of the spreading sequence 121 composed of the channelization code 122 and the scramble code 123 play an important role in determining the radio link performance. To better understand this performance, consider two interference scenarios (ie, inter-cell interference and intra-cell interference).

  Inter-cell interference is interference that occurs from one or more neighboring cells. If significant energy from other cells is present at the receiver in addition to energy from the home cell, the cross-correlation characteristics of the received waveform have a significant effect on link performance. Overlapping sets of channelization codes 122 can be used in two neighboring cells (the home cell and its neighboring cells). When overlapping channelization codes 122 are used in neighboring cells, the correlation characteristics of the received waveform are (1) scrambled sequence performed in the home cell, (2) scrambled sequence 121 performed in the neighboring interference cell, and (3 ) Each signal is mainly affected by the advanced radio propagation channel.

Link performance is adversely affected if the cross-correlation characteristics between two or more signal sequences arriving at the receiver during the same time slot are poor. Since the scrambled component of the entire spreading sequence 121 is cell-specific, and the set of available channelization codes 122 is limited to a relatively small set of values, a spreading sequence 121 with poor cross-correlation characteristics can be obtained. There is always the possibility of interfering with each other and thus constantly reducing system performance.

  Unlike inter-cell interference, intra-cell interference is interference that originates from within the cell. Channelization codes can be designed to be orthogonal, as the selected code has ideal cross-correlation properties. Orthogonality is often lost before the signal reaches the receiver. Orthogonality can be lost due to the time dispersion characteristics of the radio channel. Orthogonality between two or more uplink signals can also be lost if uplink bursts transmitted in the same time slot arrive at the base station at different times.

  Combining wireless transmission interleaving and forward error correction (FEC) helps to resolve short-term signal power fluctuations (fading) in wireless channels. In the above approach, data is encoded over a period spanning multiple fading events and an interleaver is used to evenly distribute the effects of the resulting bit errors across the received signal. The power of the forward error correction code can then recover the aforementioned slight gaps or errors in the received data. If the signal is not significantly degraded and forward error correction and interleaving are functioning properly, the underlying information content can be delivered without error.

  Forward error correction and interleaving can also help reduce error bursts caused by two signal sequences having instantaneously poor cross-correlation characteristics. Forward error correction also provides the advantage of reducing the overall variation seen in link performance across users and the same variation in the time domain. Forward error correction can also improve the stability of the process that controls the quality of the signal traveling over the wireless link.

  Using the form of time diversity on a frame basis, part of the influence of inter-cell interference on the cross-correlation characteristics can be reduced. For example, the 3GPP system implements cell parameter ID cycling. In the aforementioned system, two scrambling codes are assigned to each cell. Odd frames are encoded with the first scramble code and even frames are encoded with the second scramble code.

  If the system uses a single scramble code and operates in an environment where the cross-correlation code is consistently degraded by a single selected scramble code, the cross-correlation characteristics are always poor. If the system uses two scrambling codes in the same environment, the cross-correlation characteristics can be poor for only half the time. If a sequence has poor cross-correlation characteristics with other signals in one frame, the next sequence may have better cross-correlation characteristics in the next frame.

FIG. 3 shows a form of code diversity using frame-based cell ID cycling. In this example, the first spreading sequence having a unique scramble code (C _s1 ) is used as the sequence in the odd frame in the first cell (cell # 1). The sequence in the odd frame in the second cell (cell # 2) uses the second spreading sequence having a unique scramble code (C _s2 ). Similarly, the sequence in the even frame in the first cell uses the third scramble code (C _s3 ). The sequence in the even frame in the second cell uses the fourth scramble code (C _s4 ). In this example, the cross-correlation characteristic between the first cell and the second cell of the code used in the odd frame is poor.

Fortunately, the cross-correlation characteristics of the codes used in even frames are good. Variations in correlation characteristics are due to variations in the cell specific scramble code (C _si ).

  In this example, further link performance can be achieved if forward error correction is performed over a transmission time interval (TTI) of two radio frames (20 ms) or more. FEC can be applied to frame pairs in a cell. Link performance can be further improved by using interleaving.

  In addition to the scramble code varying with the cell parameter ID, the midamble sequence can also vary. This can lead to a similar randomization of the cross-correlation between the arriving midamble waveforms. This can be exploited to calculate a better channel estimate at the receiver.

  By moving more error correction and retransmission control functions from the base station controller (such as RNC) to the base station (such as Node B), the wireless communication system can reduce the latency of control, transmission and retransmission Is possible. For packet data, minimizing transmission latency is a goal in providing high throughput that is perceived by the end user. While high latency appears to the user as simply a low speed data link, low latency provides the user with the perception that they are connected over a high throughput data link.

  In current 3GPP systems with frame-based cell ID cycling, data must be transmitted over 20 ms TTI to achieve the benefits of code diversity. This immediately results in latency for the radio link and means that transmissions with a TTI of less than 20 ms cannot benefit from frame-based code diversity. Frame based code diversity is not sufficient for low latency (<20 ms) transmission with current 3PP approach.

  Furthermore, the current 3GPP cell parameter ID cycling aims to improve the situation in case of inter-cell interference. Lack of consideration for in-cell interference.

  In a particular embodiment of the invention, the TTI is a maximum of one radio frame. Each transmission in the TTI consists of one or more time slots. In 3.GPP UTRA TDD at 3.84 megachips per second (Mcps), one radio frame is 10 ms long and contains 15 time slots (of which up to 14 can be allocated for uplink traffic) . Within the system, time slot and channelization code resources are likely to be allocated by network entities (such as base stations and base station controllers) relatively fast (eg, on a frame-by-frame basis).

  The number of time slots allocated to a user and the channelization codes allocated are likely to vary depending on the user's data traffic needs. In general, for users who require high throughput, it is common for a user to be assigned more than one time slot per radio frame. In a particular embodiment, a single code is assigned for each uplink time slot. In other embodiments, multiple codes are assigned per uplink time slot. In certain embodiments, a single code is assigned for each downlink time slot. In other embodiments, multiple codes are assigned for each downlink time slot.

  In particular embodiments, the code or codes used for transmission are changed for each user in the radio frame. Thus, for transmissions that span multiple code variation periods within the TTI and are forward error corrected, the benefits of code diversity can be realized and the capacity and performance of the system can be improved.

  In a particular embodiment, the spreading sequence can be changed on a time slot basis by changing the spreading sequence. In a specific embodiment, the spreading sequence can be changed in time units by changing the scramble sequence in time units. In other embodiments, the spreading sequence can be changed in half-time slot units. That is, the first half of the payload (210 in FIG. 2) is encoded with the first spreading sequence, and the second half of the payload (220 in FIG. 2) is encoded with the second spreading sequence. If only two scrambling sequences are assigned to a cell and the cell is encoded in half-time slots, all time slots are encoded with the same scrambling code pair. If only four scrambling sequences are assigned to a cell and the cell is encoded in half-time slots, every other time slot is encoded with the same scrambling code pair. If two scramble sequences are assigned to a cell and the cell is encoded in units of time slots, every other time slot is encoded with the same scramble code.

  FIG. 4 shows a code diversity transmission technique in the case of low latency transmission. FIG. 4 may correspond to an uplink signal or a downlink signal. At 410, user data is provided to the encoding system. Particular embodiments include an FEC device 420, an interleaving device 430, and a code mapping / distribution device 440. Other embodiments do not include the FEC 420 and / or the interleaver 430. In certain embodiments, user data is input to the FEC device 420. The output of FEC 420 is supplied to interleaver 430. The input of the code mapping / distribution device 440 can be user data from 410 or user data supplied via one or both of 420 and 430.

In particular embodiments, user data is processed by one or both of the FEC device 420 and interleaver 430 described above. User data that has been pre-processed or not pre-processed is provided to a code mapping / distribution device 440. The code mapping / distribution device 440 parses user data into symbol sequences. A symbol represents one or more bits. When cyclic coding is performed in units of time slots, the code mapping / distribution device 440 parses user data into time slot data blocks.

FIG. 4 shows a code mapping / distribution device 440 that parses user data in three passes. The first pass of user data is encoded by code sequence 1. The second pass of user data is encoded by code sequence 2. The Nth pass of user data is encoded by a code sequence N. Code sequence 1 may represent a unique scramble code. Alternatively, the code sequence 1 can represent a unique spreading sequence. In this example, the three codes (code sequences 1, 2 and N) are different. Three time slots filled with uplink traffic in one frame are encoded with three different codes. In frame repetition pattern 1, the same three codes can be used for the next three uplink time slots in the next frame. In frame repetition pattern 2, three different codes can be used for the next three uplink time slots in the second frame, and then the original three codes are used in the next frame in the third frame. It can be used once again for 3 uplink time slots.

  In a particular embodiment, each uplink time slot in the frame is assigned a spreading sequence. Some, but not all, of the spreading sequences used in a frame may be the same. In certain embodiments, each uplink time slot in a frame is assigned a separate spreading sequence. In the above embodiment, there is no same spreading sequence used in a frame.

  In addition to cycling the scramble sequence or spreading code, the UE may cycle through the uplink and / or the midamble sequence in the burst or change as well.

  In certain embodiments, the code sequence is changed for each payload data portion. In other embodiments, the code sequence is changed for each payload data.

  A 3GPP UTRA TDD receiver is typically a decorrelated receiver. The decorrelation receiver tries to cancel the influence of the radio channel and code sequence used. The signature sequence is a convolution of the transmission sequence and the radio channel impulse response. This task is computationally intensive and as such is usually done only once per time slot or as needed (such as when the radio channel or code used changes). Thus, the high complexity part of the receiver can be executed at least at the rate of variation of the transmitted code sequence.

  The variation in the codes used in each time slot can be the same for each user or can vary between users. That is, code variation can occur in cell units, user units, or both.

  Furthermore, the channelization code component or scramble code component of the entire spreading sequence can be changed. As a further possibility, an additional variable code component is applied over the existing code. By changing the sequence within a short TTI (eg, within 10 ms), code diversity is achieved while maintaining low latency transmission.

FIG. 5 shows a form of code diversity using time slot based cell ID cycling. In the first example, the code repetition pattern of each frame is used. The frame is shown as having four uplink time slots (TS1 to TS4). The code sequence C _s1 is used for user data in the first time slot (TS1). The code sequence C _s2 is used for user data in the second time slot (TS2). The code sequence C _s3 is used for user data in the third time slot (TS1). The code sequence C _s4 is used for user data in the fourth time slot (TS2). Therefore, this first frame of the uplink time slot uses the code sequences C _s1 , C _s2 , C _s3 and C _s4 . Since the repetitive pattern is each frame, user code sequences C _s1 , C _s2 , C _s3 and C _s4 are also used for the next frame.

In the second example, a code repetition pattern of every other frame is used. The first frame is shown as having four uplink time slots (TS1 to TS4). The code sequence C _s1 is used for user data in the first time slot (TS1). The code sequence C _s2 is used for user data in the second time slot (TS2). The code sequence C _s3 is used for user data in the third time slot (TS1). The code sequence C _s4 is used for user data in the fourth time slot (TS2). Therefore, this first frame of the uplink time slot uses the code sequences C _s1 , C _s2 , C _s3 and C _s4 . Since the repetitive pattern is every other frame, the second frame uses the code sequences C _s5 , C _s6 , C _s7, and C _s8 . The code sequences C _s1 , C _s2 , C _s3 and C _s4 are still used as shown in the third frame.

  In a particular embodiment of the invention, the method changes the scrambling code assigned to the cell on a time slot basis. In order to allow correct decoding, the variation pattern can be known to both the user and the base station and can be synchronized between the transmitter and the receiver. In particular embodiments of the present invention, the code variation pattern is predetermined and the transmitter and receiver are known in advance. In a particular embodiment of the invention, the code variation pattern is signaled by the network at the start of connection or at a particular time during connection. In a particular embodiment of the invention, the code variation pattern is obtained by an algorithm that is known to the transmitter and receiver. The seed value or other parameter is notified at the start of the connection or at a specific time during the connection. In a particular embodiment of the invention, the code variation pattern is a function of system parameters known to the transmitter and receiver. For example, the system parameter can be a system frame number. In particular embodiments of the present invention, the code variation pattern itself can be changed at the time the network determines or notifies, or at a predetermined time when both the receiver and transmitter are known.

  In particular embodiments of the present invention, the spreading code used may be from an existing set of defined scrambled and channelized sequences or may be a completely new sequence. Alternatively, a new sequence set can be obtained using calculation means or algorithm means using an existing sequence as a functional input.

  In particular embodiments of the present invention, the midamble sequence used for transmission can be varied as well as the code applied to the payload portion of one or more bursts.

  Certain embodiments of the present invention provide a method of transmission in a TDD CDMA system that can realize the benefits of code diversity in the case of low latency transmission. The method comprises a transmitter that can change the code sequence used one or more times during transmission of the transmission of one or more interleaved forward error correction data units. The code sequence can be changed multiple times within a radio frame. Certain embodiments of the present invention provide a receiver that performs deinterleaving and error correction decoding of one or more received data units and is synchronized to a variable code pattern applied to a transmitter.

  Certain embodiments of the present invention provide a method for changing a transmission code by changing a scramble code one or more times during transmission of a forward error correction data unit. The scramble codes to be used are (1) a code from an existing set of scramble codes specified in the case of 3GPP TDD CDMA, and (2) a calculation means or algorithm from an existing set of scramble codes specified in the case of 3GPP TDD CDMA The code obtained by the means and / or (3) any new scramble code set. Certain embodiments of the present invention provide a method for changing a transmission code by changing a channelization code one or more times during transmission of a forward error correction data unit. The channelization codes used are (1) the components of the set of channelization codes defined in the case of 3GPP TDD CDMA and / or (2) any new channelization code set. Certain embodiments of the present invention provide a method for changing a transmission code by changing a scramble code and a channelization code one or more times during transmission of a forward error correction data unit. Certain embodiments of the present invention provide a method for changing a transmission code by adding additional codes over existing channelization and scrambling codes during transmission of forward error correction data units.

  Certain embodiments of the present invention provide a method in which the transmitter and receiver know the code variation pattern implicitly. Certain embodiments of the present invention provide a method in which the code variation pattern is explicitly signaled to the transmitter by the network or base station. Particular embodiments of the present invention provide that the code variation pattern is a parameter (a parameter known in advance by the transmitter and receiver, a parameter notified by the network or base station to the transmitter, and / or a transmitter). And a method obtained by an algorithmic means or a computing means based on parameters known from the receiver or derived from another system parameter signaled to the transmitter by the network. Particular embodiments of the present invention provide a method in which the transmission code can be changed on a time slot basis. Certain embodiments of the present invention provide a method in which the transmission code is changed in sub-time slot units (eg, data payload units, 1/2 payload units, or symbol units). Particular embodiments of the present invention provide a method for changing a transmission code on a time slot basis or sub time slot basis by changing the scrambling code and / or channelization code, or further added code.

  Particular embodiments of the present invention depend on any of the aforementioned features (including legacy uplink channels and / or enhanced uplink channels) applied to 3GPP TDD CDMA uplink systems. Provide a method represented. Particular embodiments of the present invention are represented by any of the aforementioned features (including legacy downlink channels, HSDPA and future downlink channels) applied to 3GPP TDD CDMA downlink systems. Provide a method. Certain embodiments of the present invention provide a method according to any of the foregoing, which also changes the midamble sequence used for burst transmission as a function of the variation applied to the scramble code / channelization code / further code.

  Although the present invention has been described in terms of specific embodiments and illustrative figures, those skilled in the art will recognize that the invention is not limited to the described embodiments or figures. The figures provided are only representative and may not be drawn to scale. That particular ratio may be emphasized while others may be minimized. The figures are intended to illustrate various implementations of the invention that can be understood and appropriately performed by those skilled in the art. Therefore, it is possible to implement the present invention by modifications and alterations within the scope of the claims. The above description is not intended to be exhaustive or to limit the invention to the precise form disclosed.

  Furthermore, although individually listed, a plurality of means, components or method steps may be implemented by, for example, a single apparatus or processor. Further, although individual features may be included in separate claims, in some cases they may be effectively combined and included in separate claims that a combination of features is not feasible and / or It does not suggest that it is not effective. Furthermore, the inclusion of a feature in one claim category does not suggest limiting to this category, but rather indicates that the feature is equally applicable to other claim categories. Further, the order of features in the claims does not imply any particular order in which the features must be performed, and in particular, the order of individual steps in a method claim must be performed in this order. It does not suggest that it should not be. Rather, the steps can be performed in any suitable order.

FIG. 3 shows a model of an uplink TDD CDMA encoding, transmission and reception system according to a specific embodiment of the present invention. FIG. 6 illustrates a TDD CDMA time slot burst according to a specific embodiment of the present invention. FIG. 6 illustrates a form of code diversity using frame-based cell ID cycling according to a specific embodiment of the present invention. FIG. 4 illustrates a code diversity transmission technique for low latency transmission according to a specific embodiment of the present invention. FIG. 4 illustrates a form of code diversity using time slot based cell ID cycling according to a specific embodiment of the present invention. FIG.

Claims (12)

A method for transmitting data on a link from a first wireless device to a second wireless device using a time slot in a frame, comprising:
Encoding a unit of user data to be transmitted over a transmission time interval (TTI) within a frame period with application of forward error correction;
Assigning a set of code resources for transmission of the unit of user data to the first wireless device;
Including
The method
Generating a first set of spreading codes by scrambling each code of the first set of channelization codes based on the assigned code resources with a first scrambling code;
Generating a second set of spreading codes by scrambling each code of a second set of channelization codes based on the assigned code resources with the first scrambling code;
The first set of channelization codes is different from the second set of channelization codes;
Spreading the first portion of the user data to be encoded using the first set of spreading codes;
Spreading a second portion following the first portion on a time axis of the user data to be encoded using the second set of spreading codes;
Transmitting the spread first portion of the user data to be encoded in the first portion of the frame from the first wireless device to the second wireless device;
In a second part following the first part on the time axis of the frame, the spread second part of the user data to be encoded is transferred from the first radio device to the second radio. Sending to the device;
A method characterized by. The method of claim 1, comprising:
The frame includes a plurality of time slots;
One time slot comprises a first portion and said second portion of said frame of said frame,
Method. The method of claim 1, comprising:
The first portion of the frame includes a first time slot of the frame;
The second portion of the frame includes a second time slot of the frame;
The second time slot is different from the first time slot;
Method.   4. The method of claim 3, wherein the first time slot and the second time slot are adjacent time slots.   4. The method of claim 3, wherein the first time slot and the second time slot are time slots separated by at least one time slot period. A method according to any of claims 1 to 5,
Transmitting the first portion of the user data to be encoded in the first portion of the frame from the first wireless device to the second wireless device; a first midamble sequence Including the step of transmitting
Transmitting the second portion of the user data to be encoded from the first wireless device to the second wireless device in the second portion of the frame, the first midamble. Transmitting a second midamble sequence different from the sequence,
Method.   The method according to any one of claims 1 to 6, wherein the link includes an uplink, the first radio apparatus includes a mobile radio apparatus, and the second radio apparatus includes a base station. Method.   The method according to any one of claims 1 to 6, wherein the link includes a downlink, the first radio apparatus includes a base station, and the second radio apparatus includes a mobile radio apparatus. Method. A code diversity transmitter comprising:
Logic to accept user data;
Encoding logic configured to apply forward error correction to a unit of user data to be transmitted over a transmission time interval (TTI) within a frame period;
Logic for allocating a set of code resources for transmission of the unit of user data;
Including
The code diversity transmitter is
Logic for generating a first set of spreading codes by scrambling each code of the first set of channelization codes based on the assigned code resources with a first scrambling code;
Logic for generating a second set of spreading codes by scrambling each code of the second set of channelization codes based on the assigned code resources with a first scrambling code;
The first set of channelization codes is different from the second set of channelization codes;
Code mapping and distribution logic operable to parse user data into a first part of the user data and a second part following the first part on a time axis of the user data; ;
The user data to be encoded using the first set of spreading codes to spread the first portion of the user data to be encoded and to use the second set of spreading codes. Diffusion logic operable to diffuse the second portion of the;
Coupled to the spreading logic, transmitting in the first part of the frame the spread first part of the user data to be encoded, the first part on the time axis of the frame A transmitter operable to transmit the spread second portion of the user data to be encoded in a second portion following the portion;
A code diversity transmitter. A code diversity transmitter as claimed in claim 9, comprising:
Forward error correction (FEC) logic operable to apply forward error correction to the user data, coupled between the logic for accepting the user data and the code mapping and distribution logic;
A code diversity transmitter. Code diversity transmitter according to claim 9 or 10,
Interleaving logic coupled between the logic for accepting the user data and the code mapping and distribution logic;
A code diversity transmitter.   12. A code diversity transmitter as claimed in any of claims 9 to 11, wherein the first portion of the user data comprises a time slot data block.

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