KR100790124B1 - A receiver for transmitting packet data effectively in mobile communications system supporting packet data services and method thereof - Google Patents

Abstract

A receiver and method for efficiently transmitting packet data in a mobile communication system for a packet data service are disclosed. The receiver according to the present invention includes a despreader, a control channel demodulator and a packet data channel demodulator. The despreader despreads the received signal according to a pseudo noise (PN) code and outputs the despread received signal. The control channel demodulator demodulates control information from the despread received signal. The packet data channel demodulator includes a buffer for temporarily storing the despread received signal, and when the control information is demodulated by the control channel demodulator, from the received signal stored in the buffer according to the demodulated control information. Demodulate the packet data.

Packet data transmission channel, high speed packet data transmission control channel, retransmission, variable modulation

Description

A receiver and a signal receiving method of a mobile communication system for transmitting packet data {A RECEIVER FOR TRANSMITTING PACKET DATA EFFECTIVELY IN MOBILE COMMUNICATIONS SYSTEM SUPPORTING PACKET DATA SERVICES AND METHOD THEREOF}             

1 is a diagram illustrating a structure of a forward link packet data channel for a packet data service according to an exemplary embodiment of the present invention.

2 is a diagram illustrating a structure of a forward link first packet data control channel for a packet data service according to an exemplary embodiment of the present invention.

3 is a diagram illustrating a structure of a forward link second packet data control channel for a packet data service according to an exemplary embodiment of the present invention.

4 is a diagram illustrating a forward link orthogonal spreading and frequency shift processing structure according to an embodiment of the present invention.

5 is a diagram illustrating a configuration of a mobile station receiver for demodulation for each channel of a forward link according to an embodiment of the present invention.

6 illustrates a mobile station receiver configuration for demodulation of a packet data channel according to an embodiment of the present invention.

7 is a diagram illustrating a configuration for measuring C / I values of signals in an active set according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system supporting multimedia services including voice and packet data services, and more particularly, to a receiver for efficient packet data transmission and a signal receiving method therefor.

A typical mobile communication system, for example, a code division multiple access (CDMA) mobile communication system such as IS-2000, only supports voice and low-speed circuit (line) and packet data services. However, as the technology evolves along with user demands, mobile communication systems are being developed to support high-speed packet data services, and in particular, mobile communication systems such as IS-2000 1X-EVDV (Evolution Data & Voice) are not only voice. Recently, as a system for supporting a high-speed packet data service, much attention has been paid. Therefore, in order to implement a mobile communication system capable of supporting a voice service while supporting a high speed data service, a configuration of a mobile station apparatus capable of processing high speed packet data becomes an essential element.

Accordingly, an object of the present invention is to provide a receiver and a method for efficient packet data transmission in a mobile communication system for a packet data service.

Another object of the present invention is to provide an apparatus and method for controlling a mobile station receiver operation using a control channel when retransmission and variable modulation schemes are used in a mobile communication system for packet data transmission.

A receiver of a mobile communication system for packet data transmission according to the first aspect of the present invention for achieving these objects includes a despreader, a control channel demodulator and a packet data channel demodulator. The despreader despreads the received signal according to a pseudo noise (PN) code and outputs the despread received signal. The control channel demodulator demodulates control information from the despread received signal. The packet data channel demodulator includes a buffer for temporarily storing the despread received signal, and when the control information is demodulated by the control channel demodulator, from the received signal stored in the buffer according to the demodulated control information. Demodulate the packet data.

According to a second aspect of the present invention, a receiver of a mobile station for receiving signals from a plurality of base stations included in an active set in a mobile communication system for packet data transmission includes a despreader, a measuring unit, a selector, and a first to a first receiver. And three receive path portions. The despreader despreads the received signal according to a plurality of pseudonoise (PN) codes corresponding to the base stations and outputs the despread received signals. The measurement unit measures a received signal-to-noise ratio (CIR) from the base stations and outputs a selection signal for selecting a base station having the largest CIR. The selector selects and outputs a reception signal corresponding to the selection signal from among the despread reception signals. The first receiving path unit demodulates first control information from the selected received signal. The second receiving path unit demodulates second control information from the selected received signal. The third reception path unit includes a buffer for temporarily storing the selected reception signal, and when the control information is demodulated by the first reception path unit and the second reception path unit, the third reception path unit is configured according to the demodulated control information. The packet data is demodulated from the received signal stored in the buffer.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

First of all, the present invention relates to a mobile station receiver structure for demodulating a forward channel of a mobile communication system capable of supporting a voice service and a multimedia service including a low speed circuit and a high speed packet data service using 1x bandwidth. The transmitter, channel, and receiver structure for supporting the voice service remains the same as the transmitter, channel, and receiver structure of the existing 1x system, respectively. Here, 1x bandwidth refers to a frequency bandwidth of 1.25MHz used in the existing IS-95 series North American synchronous system, and 1x system refers to a system supporting 1x bandwidth. The data service may be broadly classified into a circuit mode operation and a packet mode operation according to the type of circuit connection for the service. The data service may be various video services such as a video conference, an internet service, or the like. The dedicated line data service uses the structure of the transmitter, channel, and receiver of the existing 1x system. Therefore, in the present invention, only the structure of a transmitter, a channel, and a receiver for a packet data service will be described.

First, the channels necessary for the high-speed packet data service in the forward link of the mobile communication system according to an embodiment of the present invention are summarized in Table 1 below.

Forward Channels for Packet Data Services channel Usage Remarks Pilot Channel (PICH)  It is used for mobile station synchronous demodulation and can also be used as a means for measuring CIR for rate control. Common Channel Primary Packet Data Control Channel (PPDCCH)  Simultaneously transmitted with Pilot Channel, Packet Data Channel, Secondary Packet Data Control Channel, etc., this is used to indicate how many slots the data packet transmitted by the base station is composed of. Control channel Secondary packet Data Control Channel (SPDCCH)  Simultaneously transmitted with Pilot Channel, Packet Data Channel, Primary Packet Data Control Channel, etc., to which user the data packet transmitted by the base station is allocated (MAC_ID), whether the transmitted packet is a new packet or a retransmitted packet (SPID), and transmitted Among the four ARQ channels, the number of ARQ channels corresponds to the number of ARQ channels (ACID) and the packet size of the transmitted packet (Payload Size). Control channel Packet Data Channel (PDCH)  Simultaneous transmission of Pilot Channel, Primary Packet Data Control Channel, Secondary Packet Data Control Channel, etc. Traffic Channel

Referring to Table 1, the channels for the forward link packet data service according to the embodiment of the present invention are largely divided into a common channel, a control channel, and a traffic channel. The common channel represents a pilot channel, and provides a reference amplitude and a phase change amount for synchronous demodulation in a mobile station. The traffic channel includes a packet data channel (PDCH) through which packet data is transmitted. The control channel is divided into two channels for transmitting information related to the traffic channel. The first control channel is a first packet data control channel (PPDCCH), which indicates how many slots a packet is transmitted in the forward direction. The second control channel is a second packet data control channel (SPDCCH), which is information indicating a user's assigned packet forwarded (MAC_ID) and the packet transmitted is new. Information indicating whether the packet is a packet or retransmitted packet (SPID), information indicating the number of ARQ channels among the four ARQ channels transmitted (ACID), information indicating the size of the transmitted packet (Payload Size) And the like. In this case, since the packet transmitted through the packet data channel PDCH is received by all the users at the same time, the mobile station can distinguish the packets allocated to each user so that accurate packet transmission can be achieved. To this end, user information and packet information for a packet transmitted on the PDCH are divided into two control channels and transmitted. Therefore, packet information transmitted on PDCH cannot be determined until demodulation on two control channels is completed. However, since two control channels themselves are transmitted simultaneously with PDCH, demodulation on two control channels must be prioritized. You can demodulate correctly. In addition, it is necessary to temporarily store the received packet until demodulation of the two control channels is completed. This is because the size and modulation scheme of the packet transmitted on the PDCH and whether the packet is retransmitted cannot be known until the two control channel demodulation ends, and thus the operation behind the symbol combiner stage cannot be performed. The present invention proposes a mobile station receiver configuration including an algorithm for a demodulation device for two control channels related to PDCH demodulation and a demodulation device for PDCH according to two control channel demodulation results.

Hereinafter, the packet data channel in a situation in which a plurality of control channels for increasing the efficiency of the packet data channel exist in addition to the packet data channel in a mobile communication system for transmitting packet data at high speed. The structure of a mobile station receiver in accordance with an embodiment of the present invention for efficiently demodulating the signal will be described. In particular, the receiver of the present invention receives a base station signal including a packet data channel and a plurality of control channels to demodulate each channel and to control the operation of the packet data channel and the control channel according to the demodulated respective channel results. It is characterized by consisting of a device.

In addition, the receiver of the present invention has a structure that can control the operation of the packet data channel according to the demodulation device of the control channel and the control channel for the two control channels used for the purpose of efficiently demodulating the packet data channel It is characterized by.

In addition, the receiver of the present invention is characterized by having a structure that can simultaneously demodulate a plurality of orthogonal codes when one user uses a plurality of orthogonal codes (for example, Walsh Code).

In addition, the receiver of the present invention has a plurality of incremental redundancy / tracking combining blocks (IR / Chase Combining Block) for efficient retransmission when the retransmission is included to independently perform IR / Chase Combining operation for each packet It is characterized by having a structure.

In addition, the receiver of the present invention measures the signal-to-interference (C / I) value (CIR) of the signals in all active sets so that the best signal is always received when receiving the base station signal, and the best C among them. It has a structure that can select a signal having a / I value.

On the other hand, the receiver of the present invention determines whether the received packet data is the data allocated to the user or not as information received by the control channel. Until the demodulation of the control channel is finished, whether the currently received information is the data allocated to the user. I don't know if it is. Therefore, the receiver of the present invention has a structure for temporarily storing a signal received through a packet data channel transmitted in time alignment with the control channel until the demodulation of the control channel is completely completed. It is done. In addition, the receiver of the present invention has a structure that can remove any unnecessary operation by buffering the signal received on the packet data channel or stopping the demodulation operation according to the demodulation result of the control channel. do.

1 is a diagram illustrating a structure of a forward link packet data channel PDCH for a packet data service according to an embodiment of the present invention, and FIG. 2 is a diagram of forward link first packet data for a packet data service according to an embodiment of the present invention. Primary Packet Data Control Channel A diagram showing the structure of a PPDCCH. 3 is a diagram illustrating a structure of a forward link second packet data control channel (SPDCCH) for a packet data service according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a configuration in which signals of the PDCH, PPDCCH, SPDCCH, and pilot channels are quadrature spreaded and baseband filtered, and then multiplied by a carrier to be transmitted to an antenna. 1 to 4, the minimum transmission unit of the physical layer for packet data service is 1 slot composed of 1,536 chips, which has a duration of 1.25 milliseconds (msec).                     

Referring to FIG. 1, packet data is encoded by an encoder 400 and then added to an output of a scrambler 404 by an adder 402, and thus data scrambling. ) Is performed. The output of the adder 402 is interleaved by a Quasi Complementary Turbo Code (QCTC) interleaver (406) and then by an incremental redundancy (IR) AR by a QCTC symbol selector (408). (Automatic Repeat Request) It is appropriately punctured or repeated to construct a subpacket for the operation. The output of the QCTC symbol selector 408 is modulated into I, Q symbols by a modulator 410 and currently available for packet data channels at the base station by a symbol demultipler 412. The number of 32 Walsh Code Channels is demultiplexed into I and Q channels, respectively. Although the Walsh codes described here and hereinafter are representative orthogonal codes for signal spreading, it should be noted that other orthogonal codes may be used in place of these Walsh codes. The output of the symbol demultiplexer 412 is Walsh Spreaded by a 32 chip Walsh Cover 414, respectively. The output of the 32 chip Walsh spreader 414 is multiplied by the Walsh Channel gain controller 416 and multiplied by a Walsh Chip Level Summer 418 to obtain an I, Q angle. Will be merged by channel. Each of the I, Q outputs of the Walsh chip level adder 418 is input to the A and B terminals of FIG. 4, subjected to PN spreading and baseband filtering, and then converted to a high frequency band and transmitted through an antenna (not shown). .

FIG. 2 is a diagram illustrating a configuration of a forward link transmitter for a first packet data control channel PPDCCH according to an embodiment of the present invention. The forward link transmitter transmits a PPDCCH signal to a second packet data control channel (SPDCCH) signal and a packet data channel (PDCH) signal, a pilot channel signal, and code division multiplexing (CDM). Code Division Multiplexing).

Referring to FIG. 2, two bits representing SUBPACKET_LENGTH are transmitted in a 1.25 msec slot. This SUBPACKET_LENGTH is a bit indicating how many 1.25 msec slots a packet transmitted on a packet data channel (PDCH) consists of. By decoding the SUBPACKET_LENGTH information, the mobile station can know how many slots the packet currently being transmitted from the base station consists of. The SUBPACKET_LENGTH information is also used to determine the maximum sequence combining count for decoding when the second control channel, SPDCCH, is received. The first packet data control channel PPDCCH is configured with a short 1 slot of 1.25 msec to quickly detect the presence or absence of transmission of the PPDCCH of the base station. That is, when the PPDCCH is received, when the symbol energy of the PPDCCH is large enough to determine that the PPDCCH channel exists, the PPDCCH decoding is continued to attempt SUBPACKET_LENGTH detection. On the other hand, if the PPDCCH symbol energy is not enough to determine that the PPDCCH channel exists, the PPDCCH decoding operation is not performed.

The SUBPACKET_LENGTH is decoded by a block encoder 420, thereby generating a predetermined number of code symbols (for example, three) in a 1.25 msec slot. The output of the block encoder 420 is repeated a predetermined number of times (for example, four times) by the sequence repeater 422. The output of the sequence repeater 422 will include 12 symbols in one slot of 1.25 msec. The output of the sequence iterator 422 is modulated by a modulator 424, which may be implemented as a Quadrature Phase Shift Keying (QPSK) modulator, and then PPPPCH channel divisions in multipliers 426 and 428, respectively. Multiplied by 256 Walsh codes for The outputs of the multipliers 426 and 428 are respectively input to the A and B terminals of FIG. 4 to undergo the same processing as the signal of the PDCH.

3 is a diagram illustrating a configuration of a forward link transmitter for a second packet data control channel (SPDCCH) according to an embodiment of the present invention. The forward link transmitter is characterized in that the SPDCCH signal is transmitted by performing code division multiplexing (CDM) with a PPDCCH signal, a PDCH signal, and a pilot channel (PICH) signal.

Referring to FIG. 3, the information transmitted through the SPDCCH includes a 6-bit MAC_ID representing a user identifier (ID), a 2-bit SPID representing a subpacket ID upon retransmission, and parallel transmission. Is composed of a 2-bit ACID representing the ID of the ARQ channel of each packet and a total of 12 bits of 2-bit representing the size of the packet (Payload Size). Therefore, when demodulating the SPDCCH at the receiving end of the mobile station, it is possible to know whether the user ID and the currently transmitted packet are a new packet or whether the previous packet has been retransmitted due to an error and also the size of the transmitted packet. In addition, when the parallel transmission is used because the channel resource is sufficient by the ACID bit, ARQ processing for each transmission can be performed independently. The 12 bits of the SPDCCH are determined for each N slot, and the value of N depends on SUBPACKET_LENGTH included in the PPDCCH, as mentioned above. Therefore, the mobile station must first demodulate the PPDCCH to extract the value of SUBPACKET_LENGTH so that the value of N used for the SPDCCH can be known. N value is N = 1 when SUBPACKET_LENGTH = 1, N = 2 when SUBPACKET_LENGTH = 2, N = 4 when SUBPACKET_LENGTH = 4, and N = 4 when SUBPACKET_LENGTH = 8. The 12-bit SPDCCH information is encoded by a convolutional encoder 430. The number of symbols after being encoded by the encoder 430 is 24 symbols per SPDCCH packet. The output of the convolutional encoder 430 is repeated by a preset number (Factor = N) by the sequence repeater 432 and then input to a modulator 434, which can be implemented as a QPSK modulator, to be modulated into a QPSK signal. The output of the QPSK modulator 434 is multiplied by a 128 Walsh code representing the SPDCCH channel at multipliers 436 and 438. The outputs of the multipliers 436 and 438 are input to the A and B terminals of FIG. 4 to undergo the same processing as the signal of the PDCH.

4 is a diagram illustrating a configuration for orthogonal spreading and radio frequency (RF) band frequency transition for a forward link channel according to an embodiment of the present invention. This figure shows an operation of orthogonally spreading various channel signals of a forward link as shown in FIGS. 1 to 3 and transmitting them as a signal suitable for transmission to a terminal by frequency shifting a signal of an RF band.

Referring to FIG. 4, channel gain controllers 440 and 442 may be configured to correspond to I, Q signals of various other channels (eg, PDCH, PPDCCH, SPDCCH, Other Channels, ...). Multiply the gain corresponding to the channel. The outputs of the channel gain controllers 440 and 442 are summed again by I and Q channels by the Walsh Chip Summer 444. Quadrature Spreader 446 outputs the PN spread signal by multiplying the PN_I and PN_Q codes by the I and Q outputs of the Walsh chip summer 444. The output of the quadrature spreader 446 is filtered by Baseband Filters 448 and 450. The outputs of the baseband filters 448 and 450 are summed by the adder 456 after multiplying the carriers Cos (2πfct) and Sin (2πfct) by the multipliers 452 and 454, respectively, and the adder The output signal of 456 is finally transmitted via an antenna (not shown).

5 is a diagram illustrating a configuration of a mobile station receiver according to an embodiment of the present invention. This embodiment shows an example of processing received signals from a plurality of base stations within up to eight active sets. In the following, it is assumed that there are m fingers of a receiver, and only a case of processing a received signal for finger 0 will be described. However, it should be noted that the operation of processing the received signal for the other fingers i (i = 1, ..., m-1) is performed in the same way.

Referring to FIG. 5, a signal received through an antenna (not shown) is converted to baseband and then analog-digital converted by an analog-to-digital converter (ADC) 4. The analog-to-digital converter (ADC) 4 outputs an eight times oversampled signal, for example. For chip rate processing, the decimator 6 decimates the output of the analog-to-digital converter 4 at a chip rate (1.2288 Mcps). The output of the decimator 6 is input to PN Despreaders 1-8 (12). PN codes are also input to the PN despreaders 1-8 (12), respectively. PN codes respectively input to the PN despreaders 1 to 8 (12) are generated by PN offset mask generators 1 to 8 (8). The PN offset mask generators 8 input the PN codes generated by the finger 0 PN generator 2 and generate the PN codes by using a mask corresponding to the pilot PN offset of each active set. . As such, eight PN codes are generated by the PN offset mask generators 8 so that up to eight active sets of signals can be demodulated at the same time. When the active set is changed, the pilot PN offset of the corresponding base station is also changed. In this case, a PN offset controller 10 is provided to control the currently used PN offset mask to satisfy the pilot PN offset of the changed active set. PN despreading is performed in the PN despreaders 1 to 8 (12), respectively, and despreading result signals by the PN despreaders 1 to 8 (12) are multiplexed by a multiplexer (14). . The role of the multiplexer 14 is to select a signal of a base station having a largest Carrier to Interference (CIR) ratio (CIR) among the current active sets. In this case, a channel quality indicator (CQI) index (CQI) index is selected as the selection signal of the multiplexer 14 to allow the multiplexer 14 to select a received signal from a base station having the best C / I. Is approved. The Applied CQI Index is determined from FIG. 7 described below. The signal selected by the multiplexer 14 is divided into five receive paths and processed respectively.

The first receive path at the output of the multiplexer 14 is the path to the PPDCCH Walsh Despreader 16 for demodulation of the PPDCCH. The Walsh despreader 16 despreads the output signal of the multiplexer 14 by a Walsh code of length 256 generated by a 256 PPDCCH Walsh Generator 18. The PPDCCH complex multiplier 20 performs symbol demodulation on the signal despread by the Walsh despreader 16. In this case, the complex multiplier 20 uses the output of the channel estimator 30 for coherent demodulation. The output of the PPDCCH complex multiplier 20 is symbol aligned for combining with demodulation symbols from other fingers and then applied to a PPDCCH symbol combiner 22. The symbol combiner 22 combines the output of the complex multiplier 20 with demodulation symbols from other fingers. The PPDCCH decoder 28 inputs the output of the symbol combiner 22 to perform symbol decoding. The output of the symbol combiner 22 is also input to the PPDCCH Energy Calculator 24 to calculate symbol energy for one slot (1.25 msec). A comparator 26 compares the value of the symbol energy calculated by the energy calculator 24 with the PPDCCH detection threshold. The PPDCCH detection threshold is a reference value for determining whether the PPDCCH is present based on the energy of the output symbols of the PPDCCH symbol combiner 22, and may be set to an appropriate value by the system. When the value of the calculated symbol energy is determined by the comparator 26 to be larger than the detection threshold value, that is, when it is determined that a signal exists on the PPDCH, the PPDCCH Detect_ON signal is output. The PPDCCH Detect_ON signal is provided to the PPDCCH decoder 28 to determine whether to perform a decoding operation on the currently combined symbols. That is, when the output of the PPDCCH energy calculator 24 is larger than the PPDCCH detection threshold, a signal exists on the PPDCCH. Therefore, decoding of the output symbols of the PPDCCH symbol combiner 22 is performed. On the contrary, if the output of the PPDCCH energy calculator 24 is smaller than the PPDCCH detection threshold, since no signal exists on the PPDCCH, decoding of the output symbols of the PPDCCH symbol combiner 22 is not performed. Do not. When the decoding is performed by the PPDCCH decoder 28, the slot length of the packet currently being received on the packet data channel can be known, and the maximum sequence normalization is performed when demodulating the SPDCCH, which is the second control channel. (maximum sequence normalization) can be determined.

The second receive path at the output of the multiplexer 14 is the path input to the channel estimator 30. The channel estimator 30 estimates the amplitude and phase change amount of the signal by the channel. The value estimated by the channel estimator 30 is input to the PDCCH complex multiplier 20 and used for symbol demodulation on the PPDCCH as already mentioned, as well as to the finger 0 lock detector 32. It is used to determine the lock status of finger 0. When the sync state of finger 0 is detected, the finger 0 sync detector 32 outputs a finger 0 sync detection signal. The finger 0 sync detection signal is also applied to the symbol combiner 22 and the SPDCCH symbol combiner 44, which will be described later.

The third receive path at the output of the multiplexer 14 is a path that is input to a Finger 0 Symbol Demapping Reference Level Calculator 34. The symbol demapping reference level calculator 34 calculates a reference level value for symbol demodulation. The value calculated by the symbol demapping reference level calculator 34 is output as a finger 0 reference level value, which is combined with reference level values corresponding to other fingers.

The fourth receive path at the output of the multiplexer 14 is the path to the SPDCCH Walsh Despreader 38. The output of the multiplexer 14 is input to the SPDCCH Walsh despreader 38 for demodulation of the second packet data control channel SPDCCH to perform Walsh despreading. At this time, the Walsh code inputted to the Walsh despreader 38 for the despreading operation is generated by the 128 SPDCCH Walsh Generator 36. The output of the Walsh despread 38 is applied to an SPDCCH Complex Multiplier 40 to perform coherent symbol demodulation. The multiplication result by the complex multiplier 40 is applied to the SPDCCH normalization block 42. The normalizer 42 is for normalizing a sequence repetition signal. The operation of the normalizer 42 is cleared or held according to the decoding result by the SPDDCH decoder 46 which will be described later. The output of the normalizer 42 is time aligned for combining with the normalization output from the other fingers and then applied to the SPDCCH Symbol Combiner 44. The symbol combiner 44 combines the output of the normalizer 42 with the outputs from (m-1) other fingers. In this case, the finger coupled by the symbol combiner 44 is determined according to a result value of Finger i Lock Detection (i = 0, .. m-1). The SPDCCH decoder 46 decodes the signal combined by the symbol combiner 44. If decryption is successful, information such as a user ID (MAC_ID), a subpacket ID (SPID), an ARQ channel ID (ACID), and a packet size (Payload Size) can be known. If the decoding by the decoder 46 is successful (when an ACK occurs), the symbols stored in the normalizer 42 are all cleared. On the contrary, when decryption is not successful (NACK occurs), information such as user ID (MAC_ID), subpacket ID (SPID), ARQ channel ID (ACID), and packet size is not known. In this case, the symbols stored in the normalizer 42 are held and try to decode again after receiving the next sequence. At this time, since the same sequence is repeatedly received, a function for normalizing the sequence symbol size is required, and the block for performing this function is the normalizer 42. At this time, the number of sequence repetitions of the SPDCCH is determined according to the SUBPACKET_LENGTH obtained by the decoder 28, and the number of maximum sequence normalization can be known by the SUBPACKET_LENGTH value.

The fifth receive path of the multiplexer 14 output is the path to the PDCH Walsh Despreader 50. The Walsh despreader 50 despreads the output of the multiplexer 14. At this time, the PDCH Walsh code is not used for the Walsh despreading operation by the Walsh despreader 50. The PDCH Walsh code is generated by the PDCH Walsh Generator 48. The number of Walsh codes generated by the Walsh generator 48 depends on the number of Walsh codes used by the base station for the PDCH when sending current packet data. For example, if the Walsh code used for the PDCH in the base station is 32 Walsh codes, 32 Walsh codes are generated, and up to 28 of them are possible. From the Walsh despreader 50, n parallel signals despread are output. A PDCH complex multiplyer 52 uses the output of the channel estimator 30 to perform coherent symbol demodulation on the despread result signal by the Walsh despreader 50. The output of the complex multiplier 52 is time aligned for combining with the symbol demodulation results from the other fingers and then n parallel I-Irm finger 0 symbols, n Output as a parallel Q-arm finger 0 symbol.

FIG. 6 is a diagram illustrating a configuration of a forward link receiver for a packet data channel PDCH according to an embodiment of the present invention, wherein the receiver processes PDCH after Walsh despreading and complex multiplication processing are performed on the PDCH described with reference to FIG. 5. Shows the configuration.

Referring to FIG. 6, n parallel I-arm finger 0 symbols and n parallel Q-arm finger 0 symbols output from the complex multiplier 52 shown in FIG. 5 include the PDCH I-channel combiner 100 and the Q-channel combiner ( 102 respectively. At this time, the I-arm combiner 100 and the Q-channel combiner 102 are also inputted with I-arm symbols and Q-arm symbols from (m-1) different fingers each consisting of n parallel symbols. Accordingly, the I-channel combiner 100 combines m I-arm finger symbols (I-Arm Finger i Symbol (i = 0, .. m-1)), and the Q-channel combiner 102 is m. Q-arm finger symbols Q-Arm Finger i Symbol (i = 0, .. m-1) are combined. In this case, whether the symbol combining operation is performed by the I-channel combiner 100 and the Q-channel combiner 102 is determined by the finger sync detection signals output from m fingers (finger i lock detections (i = 0..m-1). Is controlled according to The n parallel outputs from the I-channel combiner 100 and the Q-channel combiner 102 are input to a PDCH I-channel symbol multiplexer 104 and a PDCH Q-channel symbol multiplexer 106, respectively, for symbol multiplexing. do. The symbols output from the I-channel symbol multiplexer 104 are the first symbols of Walsh code 1 from the I-channel combiner 100, the first symbols of Walsh code 2, ..., Walsh code n The first symbol of, the second symbol of Walsh code 1, the second symbol of Walsh code 2, the second symbol of Walsh code 2, ‥‥, and the second symbol of Walsh code n have the same order, and the output symbols in this order are PDCH I A variable length symbol buffer 108 is input to the female variable length symbol buffer 108. Similarly, the symbols output from the Q-channel symbol multiplexer 106 are the first symbol of Walsh code 1 from the Q-channel combiner 102, the first symbol of Walsh code 2, the Walsh code. The first symbol of n, the 2nd symbol of Walsh code 1, the second symbol of Walsh code 2, ‥‥, and the second symbol of Walsh code n have the same order, and the output symbols in this order are PDCH A Q-arm variable length symbol buffer 110 is input to the Q-arm variable length symbol buffer 110.

Symbols stored in the I-arm variable-length symbol buffer 108 and the Q-arm variable-length symbol buffer 110, that is, the symbols received on the current PDCH, are symbol de-mapped (demodulated) according to the MAC_ID demodulated in the SPDCCH. Whether or not to perform demapping is determined. That is, when the MAC_ID value obtained from decoding the SPDCCH is equal to the ID value assigned to the current user, the controller (not shown) generates a buffer read start signal to the symbol buffers 110 and 112. By having the stored symbols read out, symbol demodulation is performed by a subsequent symbol demapper 114 (Symbol Demapper). On the contrary, when the MAC_ID value obtained from the SPDCCH decoding result is different from the ID value assigned to the current user, the controller generates a clear signal to clear the symbols stored in the symbol buffers 110 and 112 to clear the symbol demapper. The symbol demodulation is not performed by 114. In addition, the controller uses the SUBPACKET_LENGTH value obtained from the decoding result of the PPDCCH, the packet size (Payload size) obtained from the decoding result of the SPDCCH, and the available Walsh Code Number obtained from another common channel. The buffer size of the symbol buffers 108 and 110 is determined. As previously mentioned, the symbols stored in the buffers 110 and 112 are read by the buffer read start signal and input to the symbol demapper 114. The symbol demodulator 114 inputs the I-arm and Q-arm symbols from the buffers 110 and 112 and uses these input symbols to reconstruct a symbol before modulation. In this case, an appropriate symbol demodulation reference level is required to reconstruct a symbol according to a modulation scheme such as quadrature amplitude modulation (QAM) and phase shift keying (8-PSK) by the symbol demodulator 114. This symbol demodulation reference level is provided from PDCH demodulation reference level combiner 112. The demodulation reference level combiner 112 combines all finger reference levels (Finger i Reference Level (i = 0, .... m-1)) output from the respective fingers and outputs a symbol demodulation reference level value. In the finger reference level combining operation, the demodulation reference level combiner 112 uses only the reference levels of the finger synchronized using a finger lock detection signal (Finger i Lock Detection (i = 0, .. m-1)). To combine. The parallel stream from the symbol demodulator 114 is converted into a serial stream by a PDCH parallel to serial converter 116.

The PDCH demultiplexer 118 inputs and demultiplexes the serial stream from the parallel / serial converter 116. At this time, the demultiplexing operation by the demultiplexer 118 depends on the ACID signal. In other words, the demultiplexer 118 inputs a serial stream from the parallel / serial converter 116 and selects a packet according to an ACID signal to generate PDCH redundancy increase / track combining (IR / Chase Combining) blocks 1 to 4 (120). In the corresponding block. ACID is used for IR / Chase Combining by distinguishing each packet independently when one user performs parallel transmission when channel resources are sufficient. In other words, if ACID = 1, IR / Chase Combining 1 is used, if ACID = 2, IR / Chase Combining 2 is used, if ACID = 3, IR / Chase Combining 3 is used, and ACID = 4 In case of IR / Chase Combining 4 is used. Here, PDCH IR / Chase Combining is a functional block that plays a role of recovering a packet error by requesting retransmission when an error occurs while transmitting a packet through the PDCH. The buffer size in each IR / Chase Combining block varies depending on the packet size, and the retransmission packet is indicated by the SPID (Subpacket Identification). The PDCH multiplexer 122 selects and outputs a block corresponding to a specific ACID from the IR / Chase Combining block 120. In addition, in order to independently perform Ack / Nack processing for PDCH IR / Chase Combining for each ACID, the IR / Chase Combining block 120 is assigned to a block that matches the ACID of the decoded packet according to Ack / Nack of the currently decoded packet. Buffer Clear / Hold operation is performed.

The PDCH segment separator 124 inputs an IR Combining Output from the multiplexer 122 and inputs each of the input symbols into a system part (or an information word symbol part) and a non-system (Non). Split into Systematic parts (or parity symbol parts) so that they are deinterleaved, respectively. The first deinterleaver (Deint1) 126 deinterleaves the symbols corresponding to the system part. The second to fourth deinterleavers (Deints 2 to 4) 128 to 134 deinterleave the symbols corresponding to the non-system part. A PDCH deinterleaver multiplexer 136 multiplexes the output of the deinterleavers 126 to 134. A PDCH descrambler 138 inputs and descrambles the multiplexed output from the deinterleaver multiplexer 136. The PDCH turbo decoder 140 decodes symbols descrambled by the descrambler 138. Generates a control signal for clearing / holding the buffers of the corresponding PDCH IR / Chase Combining blocks 1 to 4 120 according to the Ack / Nack result of the packet decoded by the turbo decoder 140. do. This control signal is valid only for the PDCH IR / Chase Combining block corresponding to the ACID of the currently decoded packet. That is, when the decoding result of the PDCH turbo decoder 140 is good, an ACK signal is generated to clear the PDCH IR / Chase Combining i buffer having the ACID of the currently decoded packet. New Packet) can be received. On the other hand, if the decoding result is not good (Bad), the PDCH IR / Chase Combining i buffer which generates the Nack signal and holds the ACID of the currently decoded packet is held and then the PDCH IR / Chase for the packet to be retransmitted and received. Allow combining to continue.

7 is a diagram illustrating a configuration of an apparatus for measuring a carrier to interference (C / I) value according to an embodiment of the present invention. This embodiment shows an example of measuring a carrier to interference (C / I) value for a base station pilot signal in up to eight active sets. In the following, it is assumed that there are m fingers of the receiver, and only a case in which a C / I value for finger 0 is measured will be described. However, it should be noted that the C / I value measurement operation for the other fingers i (i = 1, ..., m-1) is performed in the same manner.

Referring to FIG. 7, as described above with reference to FIG. 5, the input signal is despreaded by the PN despread blocks 1 through 8 (12), which are formed of a plurality of despreaders via a decimator 6. do. At this time, the PN despread block 12 is composed of eight despreaders corresponding to the number of base stations in the active set. Each despreader receives a received signal passing through the decimator 6 and generates a PN offset mask. The PN code generated by each of the PN offset mask generators 300 to 314 of the block 8 is input to perform a despreading operation. The PN offset mask generators 300 to 314 generate a PN code according to the PN code generated by the finger 0 PN generator 2 and the PN offset value provided from the PN offset controller 10. The PN offset controller 10 is provided with a channel quality indicator (CQI) index value and provides the PN offset mask generators 300 to 314 with PN offset values corresponding to each of the base stations in the active set. do. Output signals from the respective despreaders of the PN despread block 12 are applied to the corresponding meter of the C / I measurement blocks 200-214.

Each meter of the C / I measurement blocks 200-214 measures the C / I value for finger O of each base station pilot signal. That is, the C / I measurer 200 measures the C / I value of finger 0 of the sector 1 base station pilot signal. The C / I meter 202 measures the C / I value for finger 0 of the Sector 2 base station pilot signal. The C / I measurer 204 measures the C / I value for finger 0 of the Sector 3 base station pilot signal. The C / I measurer 206 measures the C / I value for finger 0 of the Sector 4 base station pilot signal. The C / I meter 208 measures the C / I value for finger 0 of the Sector 5 base station pilot signal. The C / I meter 210 measures the C / I value for finger 0 of the Sector 6 base station pilot signal. The C / I meter 212 measures the C / I value for finger 0 of the Sector 7 base station pilot signal. C / I meter 214 measures the C / I value for finger 0 of the Sector 8 base station pilot signal. The C / I values measured by each meter of the C / I measurement blocks 200-214 are then each combined for C / I values measured for (m-1) other fingers. It is time aligned by being applied to and stored in the I FIFOs (First-In First-Outs) 216 to 230.

The C / I values time-aligned by the C / I FIFOs 216-230 for each of Sectors 1-8 are applied to the Sectors 1-8 C / I Combiners 232-246, respectively. do. The C / I combiners 232-246 combine the C / I values from corresponding FIFOs of the C / I FIFOs 216-230 and C / I values for other fingers, respectively. That is, C / I combiner 232 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 1) in the active set. C / I combiner 234 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 2) in the active set. C / I combiner 236 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 3) in the active set. C / I combiner 238 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 4) in the active set. C / I combiner 240 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 5) in the active set. C / I combiner 242 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 6) in the active set. C / I combiner 244 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 7) in the active set. C / I combiner 246 combines the C / I values for fingers i (i = 0, ..., m-1) of base station (sector 8) in the active set.

A sector serving sector selector 248 inputs the C / I values for the fingers of each base station combined by the C / I combiners 232 to 246 and the most among the input C / I values. A signal having a large C / I value is selected and the index of the signal is output as a CQI (Channel Quality Indicator) index. In this case, the outputs of the sectors 1 to 8 C / I combiners 232 to 246 correspond to values of signal indexes 1 to 8, respectively. The output of sector selector 248 is applied to CQI index buffer 1 250. The output of the CQI index buffer 1 250 is applied to the CQI index buffer 2 252 again. The CQI index buffer k 254 indicates the last stage of the CQI index buffer, and the K value at this time may be appropriately set according to scheduling. The reason why the index buffer is configured in multiple stages is that the C / I value is measured in units of slots (1.25 msec), but the base station selected by the C / I value changes only once per packet. That is, the index buffers are configured in multiple stages so that an operation of measuring a C / I value and selecting a base station according to the result is performed once every packet. The CQI index value output from the CQI index buffer 254 is applied to the multiplexer 14 of FIG. 5 to designate a base station signal to be selected in the next packet. In this way, even when the length of one packet is long, the base station is not changed during the transmission of the packet, thereby increasing the complexity of scheduling due to frequent switching of the base station.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, the present invention proposes a mobile station receiver structure using a retransmission and a variable modulation scheme in a mobile system for packet data transmission. When the proposed mobile station receiver structure is used, high-speed wireless packet data can be efficiently received. . In addition, the parallel transmission receiver structure proposed by the present invention can increase throughput in a packet communication system by maximizing the use of system resources in a good channel condition.

Claims (27)

In the receiver of a mobile communication system for packet data transmission, A despreader which despreads the received signal according to a pseudo noise (PN) code and outputs the despread received signal; A control channel demodulator for demodulating control information from the despread received signal; A buffer for temporarily storing the despread received signal, and demodulating packet data from the received signal stored in the buffer according to the demodulated control information when control information is demodulated by the control channel demodulator; And a data channel demodulator. The receiver of claim 1, wherein the control information includes first information indicating the number of slots constituting the packet data. The control information of claim 2, wherein the control information includes: second information indicating user allocation to the packet data, third information indicating whether the packet data is a new packet or a retransmission packet, and the packet data is transmitted through a predetermined unit channel. And fourth information indicating which channel corresponds to which channel, and fifth information indicating the size of the packet data. The receiver of claim 3, wherein the set unit channel is an ARQ channel. The method of claim 3, wherein the control channel demodulation unit, A first control channel demodulator for demodulating the first information; And a second control channel demodulator for demodulating the second to fifth information. The receiver of claim 1, wherein the despreader despreads a received signal from a base station having the largest signal-to-noise ratio (CIR) among a plurality of base stations included in an active set. 7. The receiver of claim 6, further comprising a PN code generator for generating PN codes for each of the plurality of base stations. The receiver of claim 1, wherein the size of the buffer is variably determined in consideration of the number of available orthogonal codes and the control information. A receiver of a mobile station for receiving signals from a plurality of base stations included in an active set in a mobile communication system for packet data transmission, A despreader which despreads the received signal according to a plurality of pseudo noise (PN) codes corresponding to the base stations and outputs despread received signals; A measuring unit measuring a received signal-to-noise ratio (CIR) from the base stations and outputting a selection signal for selecting a base station having the largest CIR; A selector for selecting and outputting a reception signal corresponding to the selection signal from the despread reception signals; A first receiving path unit for demodulating first control information from the selected received signal; A second receiving path unit for demodulating second control information from the selected received signal; A buffer for temporarily storing the selected received signal, and when control information is demodulated by the first and second receiving path portions, the received signal stored in the buffer according to the demodulated control information. And a third receiving path section for demodulating packet data. The receiver of claim 9, wherein the first control information is information indicating the number of slots constituting the packet data. The method of claim 9, wherein the second control information includes information indicating user allocation to the packet data, information indicating whether the packet data is a new packet or a retransmission packet, and when the packet data is transmitted in a preset unit channel. And information indicating which channel corresponds to which channel, and information indicating the size of the packet data. The receiver of claim 11, wherein the set unit channel is an ARQ channel. 10. The receiver of claim 9 further comprising a PN code generator for generating PN codes for each of the plurality of base stations. 10. The receiver of claim 9, wherein the size of the buffer is variably determined in consideration of the number of available orthogonal codes and the control information. 10. The receiver of claim 9, further comprising a channel estimator for estimating a channel signal from the selected received signal and providing an estimation result to the respective reception path portions. The method of claim 15, wherein each of the receiving path portion, An orthogonal code despreader for despreading the selected received signal according to an orthogonal code on a corresponding path; A complex multiplier for complex multiplying the orthogonal code despread signal according to the estimation result; And a decoder for decoding the multiplication result by the complex multiplier. 17. The receiver of claim 16, wherein the buffer is connected between the complex multiplier and the decoder of the third receive path portion. 18. The receiver of claim 17, further comprising a demodulator connected between the buffer and the decoder of the third receive path section and demodulating a received signal stored in the buffer. 19. The receiver of claim 18, further comprising a calculator for calculating a demodulation reference level to be used in a packet data demodulation operation in the demodulator from the selected received signal. 19. The receiver of claim 18, further comprising a block for incrementally redistributing / tracking combining (IR / Chase Combining) the received signal demodulated by the demodulator for each packet according to the second control information. 19. The receiver of claim 18, wherein the reception signal stored in the buffer is cleared when the decoding result by the decoder of the third reception path part is good. 19. The receiver of claim 18, wherein the reception signal stored in the buffer is held when the decoding result by the decoder of the third reception path unit is not good. In the signal receiving method of a mobile communication system for packet data transmission, Despreading the received signal according to a pseudo noise (PN) code and outputting the despread received signal; Demodulating control information from the despread received signal; Temporarily storing the despread received signal in a buffer until the control information is demodulated; And demodulating packet data from the received signal temporarily stored in the buffer according to the demodulated control information when the control information is demodulated. 24. The method of claim 23, wherein the control information includes first information indicating the number of slots constituting the packet data. 25. The method of claim 24, wherein the control information includes: second information indicating user allocation to the packet data, third information indicating whether the packet data is a new packet or a retransmission packet, and the packet data is transmitted through a predetermined unit channel. And fourth information indicating which channel corresponds to which channel, and fifth information indicating the size of the packet data. The method of claim 25, wherein the set unit channel is an ARQ channel. 24. The method of claim 23, wherein the size of the buffer is variably determined in consideration of the number of available orthogonal codes and the control information.

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