JP2005217741A - Normalizing method of received signal and receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CDMA receiver capable of determining an optimum reference level in the case that linear decoding processing and nonlinear decoding processing are intermingled due to the presence of multiplexed signals and obtaining an excellent reception characteristic independently of the environment of transmission paths. <P>SOLUTION: A first reference level determining means 15 discriminates a coding type of a channel signal included in a received frame signal. Further, the first reference level determining means 15 determines a preferential coding type to be prioritized in normalization among coding types of the channel signal included in the frame signal by using information from a high order layer, and determines a first reference value optimum to the normalization in the preferential coding type. A first normalizing processing means uses the first reference value to normalize the frame signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to normalization of the level of a received signal before turbo decoding or Viterbi decoding that employs a max * -log-MAP algorithm, and in particular, excellent decoding characteristics in a W-CDMA communication system in which a steep fading environment occurs on a transmission path. It relates to a normalization method that makes it possible to obtain

  In the decoding unit in the W-CDMA receiver, it is preferable to reduce the amount of memory used for channel decoding as much as possible. Therefore, in general, after receiving RAKE data expressed in a precise floating-point format is quantized into a soft decision format expressed in a predetermined number of bits, a series of channel decoding processes and turbo decoding processes or Viterbi decoding processes Is done. As an example, the accurate floating-point format for expressing the received RAKE data is 16 bits in total including a mantissa part 10 bits and an exponent part 6 bits. The soft decision format after quantization is 8 bits per symbol as an example.

  In turbo decoding using the conventional Viterbi decoding process or the max-log-MAP algorithm, only the linear component affects the likelihood estimation. Therefore, normalization is required so that the reception level (likelihood) can be expressed to the maximum with a predetermined number of bits in the quantization (see, for example, Patent Document 1).

  A method of normalizing the received signal in accordance with the maximum level in the range to be normalized is considered to be the best. Therefore, conventionally, when quantizing to the soft decision format, the received signal is normalized with reference to the signal of the maximum reception level.

  FIG. 5 is a block diagram showing a configuration of a conventional CDMA receiver. Referring to FIG. 5, the conventional CDMA receiver includes a path search unit 51, a finger unit 52, and a decoding unit 53. The decoding unit 53 includes a memory 54, a first reference level determination unit 55, a first normalization processing unit 56, a first channel decoding unit 57, a memory 58, and a TrCH processing unit 59.

  A plurality of TrCH processing units 59 are provided, and each of them performs processing for each TrCH. The TrCH processing unit 59 includes a second reference level determination unit 60, a second normalization processing unit 61, a 1st deinterleave processing unit 62, a selector 63, a turbo decoding processing unit 64, a Viterbi decoding processing unit 65, and a second channel. A decoding unit 66 is provided.

  The path search unit 51 detects a path from the received baseband signal and notifies the finger unit 52 of the path.

  The finger unit 52 despreads the received baseband signal and performs a RAKE combining process based on the path information notified from the path search unit 51. In a wireless section in the W-CDMA communication system, that is, between a terminal and a base station, a PhCH (Physical Channel) including a data part called DPDCH (Dedicated Physical Date Channel) and a control part called DPCCH (Dedicated Physical Control Channel). ) To communicate.

  The finger unit 52 stores data after RAKE combining of the DPDCH (hereinafter referred to as RAKE data) in the memory 54 in units of wireless frames, and notifies the decoding unit 53 of the data. The format of the RAKE data handled here is a floating-point format. For example, per 1 Symbol, the mantissa part (Mantissa) 10 bits, the exponent part (Exponent) 6 bits, a total of 16 bits,

と表現される。

It is expressed.

  At the same time, the finger unit 52 calculates the minimum value of the exponent part (Exponent) of all the symbols in the wireless frame, and notifies the first reference level determination unit 55 of the decoding unit 53 as Frame Exponent information. In addition, the finger unit 52 decodes TFCI indicating a combination of TrCHs multiplexed on the PhCH among the control information included in the DPCCH, and notifies the first channel decoding unit 17 as received TFCI information.

  The decoding unit 53 is a block mainly having a function of decoding a reception signal that has been subjected to Multiplexing and channel coding processing defined in 3GPP TS 25.212 on the transmission side.

  The first reference level determination unit 55 calculates a reference Exponent value (hereinafter referred to as a first reference EXP) based on the Frame Exponent information notified from the finger unit 52, and the first normalization processing unit 56 and The second reference level determination unit 60 is notified.

  The first normalization processing unit 56 takes out RAKE data for each frame from the memory 54, performs normalization processing on the basis of the first reference EXP calculated by the first reference level determination unit 55, The result is output to the first channel decoding processing unit 56.

  The first channel decoding processing unit 57 performs a series of channel decoding processes performed for each radio frame including 2nd deinterleave processing, PhCH combining processing, TrCH division processing, and Rate Dematching processing, and stores the results in the memory 58. .

  The TrCH processing unit 59 is a block having a function of performing a series of decoding processes for each TrCH.

  In TrCH, a TrBk (Transport Block) serving as a unit of the minimum data unit is generated every TTI (Transmission Time Interval). Here, the TTI is notified as a parameter from the upper layer for each TrCH, and can take values of 10 msec, 20 msec, 40 msec, and 80 msec (an integer multiple of a radio frame of 10 msec). Therefore, the second normalization processing unit 61 takes out the data of the corresponding TrCH for the TTI from the memory 58 when the RAKE data for the wireless frame for the TTI is stored in the memory 58, and performs normalization processing on the data. The result is output to the 1st Deinterleave processing unit 62.

  Here, the normalization is performed again by the first normalization processing unit 56 according to the reference Exponent value for each frame. However, since the levels are different among a plurality of frames in the TTI, normalization is further performed. This is to match a certain reference level.

  A second reference level (hereinafter referred to as a second reference EXP) used by the second normalization processing unit 61 is calculated based on the first reference EXP by the second reference level determination unit 60. Is done.

  The 1st Deinterleave processing unit 62 performs 1st Deinterleave processing on the signal after normalization by the second normalization processing unit 61, and sends the processed signal to the selector 63.

  The selector 63 selects either the turbo decoding processing unit 64 or the Viterbi decoding processing unit 65 according to the encoding type information notified from the upper layer (not shown), and the signal from the 1st Deinterleave processing unit 62 is selected to the selected one. Send.

  The turbo decoding processing unit 64 or the Viterbi decoding processing unit 65 performs error correction decoding processing according to a predetermined algorithm, and outputs the resulting signal to the second channel decoding processing unit 66.

  The second channel decode processing unit 66 performs a series of channel decode processing such as code block combining processing, split processing into TrBk (Transport Block), CRC check, CRC removal, etc., and the decoded data as the processing result is obtained. Output.

  FIG. 6 is a flowchart showing the operation of the first and second reference level determination units in the conventional CDMA receiver shown in FIG. FIG. 6A shows the operation of the first reference level determination unit 55, and FIG. 6B shows the operation of the second reference level determination unit 60.

Referring to FIG. 6, the first reference level determination unit 56 sets the minimum EXP as the first reference EXP (step S501), and outputs the first reference EXP (step S502). Similarly, the second reference level determination unit 60 sets the minimum EXP as the second reference EXP (step S511), and outputs the second reference EXP (step S512).
Japanese Patent Laid-Open No. 2002-237753

  On the other hand, in recent years, a max * -log-MAP algorithm improved from the max-log-MAP algorithm has been proposed and may be used for turbo decoding. The max * -log-MAP algorithm is such that a characteristic close to MAP decoding can be obtained by adding a correction term to the max-log-MAP algorithm.

  In the max * -log-MAP algorithm, when the reception level is low, for example, when the probability of the determination of +1 and the determination of −1 are almost equal, it is necessary to add a larger correction. Therefore, the conventional normalization method may not be appropriate.

  In the max * -log-MAP algorithm, a nonlinear component called this correction term is added. Therefore, in normalization, the received signal is accurately scaled according to information on the communication path (for example, signal-to-noise power ratio). Is preferred. However, a complicated decoding process is required to perform this scaling. Therefore, in order to avoid the complexity, scaling may be omitted and a method of normalizing to the maximum reception level may be used as usual.

  In conventional normalization, the levels of other signals are rounded in accordance with the high level signal in the normalization unit. Therefore, in a steep fading environment where the reception level fluctuates drastically, the overall signal level is lowered in accordance with the high level signal in the short section within the normalization unit (FIG. 3B, FIG. 4). (See (b)). Then, when the conventional normalization method is used in turbo decoding using the max * -log-MAP algorithm, in a severe fading environment, due to the influence of nonlinear components of likelihood estimation, the case of max-log-MAP Also, the decoding characteristics (BER (Bit Error Rate)) deteriorate.

  In addition, when trying to adopt an optimal normalization method for turbo decoding using the max * -log-MAP algorithm, there is an optimal normalization method for turbo decoding using the max * -log-MAP algorithm and Viterbi decoding. Different points need to be considered.

  Since the Viterbi decoding algorithm is maximum likelihood decoding, it is preferable to quantize such that a signal with a high likelihood has a high level and a signal with a low likelihood has a low level. For this reason, it is recommended that normalization is performed in accordance with the maximum reception level in the normalization unit ((a) in FIG. 3, (a) in FIG. 4).

  For this reason, it is preferable that the W-CDMA receiver selects an optimal normalization method according to the encoding type of turbo decoding or Viterbi decoding using the max * -log-MAP algorithm.

  However, at the stage of wireless frame (PhCH: Physical Channel), there is a possibility that a plurality of TrCHs (Transport Channels), which are units in which the coding types are determined, are multiplexed. In that case, since there is a possibility that a turbo code and a Viterbi code using the max * -log-MAP algorithm may be mixed, it is determined which encoding type should be selected as the optimum normalization method. It is difficult.

  For the reasons described above, the conventional CDMA receiver employs a method of normalizing based on the maximum level regardless of the encoding type. For this reason, in the conventional CDMA receiver, good reception characteristics may not be obtained depending on the environment of the transmission path.

  An object of the present invention is to determine an optimal reference level when linear decoding processing and nonlinear decoding processing coexist due to signal multiplexing, and to obtain good reception characteristics regardless of the transmission path environment. It is an object of the present invention to provide a CDMA receiver capable of performing the above.

In order to achieve the above object, the receiving apparatus of the present invention is a receiving apparatus capable of decoding a plurality of encoding types having different reference values optimum for normalization,
The channel signal encoding type included in the received frame signal is determined, and among the channel signal encoding types included in the frame signal, the priority encoding type to be prioritized in normalization is determined from the upper layer. First reference level determination means for determining a first reference value that is optimal for normalization in the priority encoding type,
First normalization processing means for normalizing the frame signal using the first reference value.

  Therefore, according to the present invention, the first reference level determination means selects an appropriate encoding type using information from the higher layer, determines an optimal first reference value for the selection, and sets the first normal value. The normalizing means can perform normalization using the first reference value.

Channel decoding processing means for performing channel decoding processing on the frame signal normalized by the first normalizing means;
A second reference level for obtaining a second reference value optimum for the coding type from the first reference value for each channel signal included in the frame signal subjected to the channel decoding processing by the channel decoding processing means. A determination means;
Second normalizing means for normalizing the channel signal using the second reference value;
The channel signal normalized by the second normalizing unit may further include a decoding processing unit that performs a decoding process appropriate for the type of encoding.

  The encoding types that can be decoded by the receiving apparatus may include non-linear decoding processing and linear decoding processing encoding types. The encoding type of the non-linear decoding process may be turbo decoding using a max * -log-MAP algorithm.

  The encoding type of the linear decoding process may be Viterbi decoding.

  Therefore, good reception characteristics can be obtained in turbo decoding using the max * -log-MAP algorithm even in a steep fading environment.

  The first reference level determination means obtains the first reference value from an average value of channel signals within a normalization unit if the decoding process of the priority encoding type is nonlinear, and the priority code If the decoding process of the normalization type is linear, the first reference value may be obtained from the maximum value of the channel signal in the normalization unit.

  In addition, when the frame signal includes channel signals of a plurality of encoding types, the first reference level determination unit gives priority to a channel signal for which the QoS is relatively increased in an upper layer. The priority encoding type may be determined by weighting. Further, the first reference level determination means may weight the channel signal using RMA information.

  Therefore, since RMA is used for weighting, weighting is performed with emphasis on channel signals intended to increase the number of repetitive symbols in the rate matching process or to reduce thinning, that is, to increase the QoS relatively. can do.

  Further, the first reference level determining means includes a channel signal encoding type included in the frame signal, a received TFCI information indicating the type of the channel signal multiplexed in the frame signal, and an upper layer. It is good also as discriminate | determining from various encoding classification information grasped | ascertained in (1).

  According to the present invention, the first reference level determining means selects an appropriate encoding type using information from the higher layer, determines the optimum first reference value, and first normalizing means Since normalization is performed using the first reference value, it is possible to determine an optimal reference value for normalization without requiring complicated processing when there is a decoding process of a plurality of encoding means. it can.

  Further, according to the present invention, it is possible to obtain good reception characteristics in turbo decoding using the max * -log-MAP algorithm even in a steep fading environment.

  Further, according to the present invention, since RMA is used for weighting, a channel intended to increase the number of repeated symbols in the rate matching process or to reduce the thinning-out, that is, to increase the QoS relatively. Since weighting is performed with emphasis on signals, it is possible to satisfactorily normalize frame signals in which channel signals of a plurality of encoding types are multiplexed.

  An embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a CDMA receiver according to an embodiment of the present invention. FIG. 1 shows, as an example, a configuration in which the present invention is applied to a base station in a W-CDMA system.

  Referring to FIG. 1, the CDMA receiver includes a path search unit 11, a finger unit 12, and a decoding unit 13. The decoding unit 13 includes a memory 14, a first reference level determination unit 15, a first normalization processing unit 16, a first channel decoding unit 17, a memory 18, and a TrCH processing unit 19.

  A plurality of TrCH processing units 19 are provided, each of which performs processing for each TrCH. The TrCH processing unit 19 includes a second reference level determination unit 20, a second normalization processing unit 21, a 1st deinterleave processing unit 22, a selector 23, a turbo decoding processing unit 24, a Viterbi decoding processing unit 25, and a second channel. A decoding unit 26 is provided.

  The path search unit 11 detects a path from the received baseband signal and notifies the finger unit 12 of the path.

  The finger unit 12 despreads the received baseband signal and performs RAKE combining processing based on the path information notified from the path search unit 11. In a wireless section in the W-CDMA communication system, that is, between a terminal and a base station, a PhCH (Physical Channel) including a data part called DPDCH (Dedicated Physical Date Channel) and a control part called DPCCH (Dedicated Physical Control Channel). ) To communicate.

  The finger unit 12 stores data after RAKE combining of the DPDCH (hereinafter referred to as RAKE data) in the memory 14 in units of radio frames and notifies the decoding unit 13 of the data. The format of the RAKE data handled here is a floating-point format. For example, per 1 Symbol, the mantissa part (Mantissa) 10 bits, the exponent part (Exponent) 6 bits, a total of 16 bits,

と表現される。

It is expressed.

  At the same time, the finger unit 12 calculates the average value and the minimum value of the exponents (Exponents) of all the symbols in the radio frame, and notifies the first reference level determination unit 55 of the decoding unit 13 as Frame Exponent information. . Here, the average value of Exponent is defined as an average Exponent value (hereinafter referred to as average EXP), and the minimum value is defined as a minimum Exponent value (hereinafter referred to as minimum EXP).

  Further, the finger unit 12 decodes TFCI indicating a combination of TrCHs multiplexed on the PhCH among the control information included in the DPCCH, and receives the first reference level determination unit 15 and the first channel decoding unit as received TFCI information. 17 is notified.

  The first reference level determination unit 15 determines the priority encoding type from the Frame Exponent information and the reception TFCI information notified from the finger unit 12 and the RMA information and the encoding type information notified from an upper layer (not shown). Then, a reference Exponent value (hereinafter referred to as a first reference EXP) optimum for the priority encoding type is calculated and notified to the first normalization processing unit 16 and the second reference level determination unit 20.

  The first normalization processing unit 16 retrieves RAKE data for each frame from the memory 14, and performs normalization processing on the RAKE data according to the first reference EXP calculated by the first reference level determination unit 15, The result is output to the first channel decoding processing unit 16.

  The first channel decoding processing unit 17 performs the signal from the first normalization processing unit 16 for each radio frame including 2nd deinterleave processing, PhCH combining processing, TrCH division processing, and Rate Dematching processing. A series of power channel decoding processes are performed, and the result is stored in the memory 18.

  The TrCH processing unit 19 is a block having a function of performing a series of decoding processes for each TrCH.

  In TrCH, a TrBk (Transport Block) serving as a unit of the minimum data unit is generated every TTI (Transmission Time Interval). Here, the TTI is notified as a parameter from the upper layer for each TrCH, and can take values of 10 msec, 20 msec, 40 msec, and 80 msec (an integer multiple of a radio frame of 10 msec). Therefore, the second normalization processing unit 21 extracts the data of the corresponding TrCH for the TTI from the memory 18 when the RAKE data for the wireless frame for the TTI is stored in the memory 18, and performs the normalization process on the data. The result is output to the 1st Deinterleave processing unit 12.

  Here, the normalization is performed again by the first normalization processing unit 16 according to the reference Exponent value for each frame. However, since the levels are different among a plurality of frames in the TTI, normalization is further performed. This is to match a certain reference level.

  The second reference level (hereinafter referred to as second reference EXP) used in the second normalization processing unit 11 is the encoding type notified from the upper layer in the second reference level determination unit 20. It is calculated based on the information and the first reference EXP obtained by the first reference level determination unit 15.

  The 1st Deinterleave processing unit 22 performs 1st Deinterleave processing on the signal after normalization by the second normalization processing unit 21 and sends the processed signal to the selector 23.

  The selector 23 selects either the turbo decoding processing unit 24 or the Viterbi decoding processing unit 25 according to the encoding type information notified from the higher layer, and sends a signal from the 1st Deinterleave processing unit 22 to the selected one.

  The turbo decoding processing unit 24 or the Viterbi decoding processing unit 25 that has received the signal from the selector 23 performs error correction decoding processing according to a predetermined algorithm, and outputs the resulting signal to the second channel decoding processing unit 26. The turbo code processing unit 24 performs nonlinear turbo decoding using a max * -log-MAP algorithm, and the Viterbi decoding processing unit 25 performs linear Viterbi decoding.

  The second channel decoding processing unit 26 performs code block combining processing, division processing into TrBk (Transport Block), CRC check, and CRC removal on the signal from the turbo decoding processing unit 24 or the Viterbi decoding processing unit 25. A series of channel decoding processes including are performed, and decoded data that is the processing result is output.

  FIG. 2 is a flowchart showing the operation of the first and second reference level determination units in the CDMA receiver shown in FIG. FIG. 2 (a) shows the operation of the first reference level determination unit 15, and FIG. 2 (b) shows the operation of the second reference level determination unit 20.

Referring to FIG. 2A, the first reference level determination unit 15 first performs priority encoding type determination processing (1) to (3) (step S101).
(1) The type of each TrCH multiplexed in the reception radio frame is determined from the reception TFCI information. The TFCI is an index indicating the combination of TrCHs multiplexed on the PhCH, the TrBk size of each TrCH, and the number of TrBk, and is originally required for the decoding process in the first channel decoding processing unit 17.
(2) The coding type of each TrCH included in the reception frame is determined by collating the coding type information for each TrCH notified from the higher layer with the TrCH information determined in (1) described above. .
(3) If the coding types of all TrCHs are the same, the priority coding type is uniquely determined by the coding type. When multiple coding types are mixed, each TrCH is weighted according to RMA (Rate Matching Attribute), then the priority of each coding type is calculated, and the coding type with the highest priority is given priority. Determine the encoding type. For example, when two TrCHs of TrCH # 0 (turbo coding, RMA: 100) and TrCH # 1 (convolutional coding, RMA: 120) are multiplexed, convolutional coding with a large RMA is set as the priority coding type. To do. Essentially, the fact that the RMA of a certain TrCH is relatively larger than the RMA of another TrCH means that the number of repetition symbols in the rate matching process is increased or that puncturing is reduced. That is, it can be said that there is an intention to relatively increase the QoS (Quality of Service) of the TrCH. Therefore, here, priority is given to the coding type of TrCH having a large RMA by using RMA for determination of the priority coding type.

  After the processes (1) to (3), the first reference level determination unit 15 determines whether the priority encoding type calculated there is a turbo code or a convolutional code (step S102).

  If the priority encoding type is a turbo code, the first reference level determination unit 15 sets the first reference EXP used as a reference in normalization as the average EXP (step S103). If the priority encoding type is a convolutional code, the first reference level determination unit 15 sets the first reference EXP to the minimum EXP (step S104). Note that Exponent is minimum indicates that the signal level is maximum.

  Next, after the processing in step S103 or step S104, the first reference level determination unit 15 outputs the first reference EXP to the first normalization processing unit 16 (step S105).

  FIG. 3 is a diagram illustrating a normalization process performed by the first normalization processing unit. Here, an example in which 1 Frame is configured with 8 Symbols is shown. FIG. 3A shows Symbol before normalization. FIG. 3B shows a normalization based on the minimum EXP. FIG. 3C shows a state normalized with the average EXP as a reference.

  Referring to FIG. 3, when each Symbol having different Exponent values for each Symbol shown in (a) is normalized with reference to the minimum EXP, as shown in (b), the smallest Exponent (maximum reception) is obtained. Level) is rounded in the direction where the dynamic range of the symbol is the largest and the levels of the other symbols are small.

  Also, when normalized based on the average EXP, as shown in (c), the dynamic range of the symbol having the average reception level is the largest, and the symbol having the reception level exceeding that is rounded to the maximum level, Also, a symbol having a reception level below that is rounded in a smaller direction.

  Referring to FIG. 2 (b), the second reference level determination unit 20 determines the corresponding TrCH coding type by associating with the coding type information for each TrCH notified from the higher layer (step S111). ).

  If the TrCH encoding type is a turbo code, the second reference level determination unit 20 calculates an average value of the first reference EXP of each frame in the TTI, and sets this as the second reference EXP ( Step S112). On the other hand, if the coding type of TrCH is a convolutional code, the second reference level determination unit 20 calculates the minimum value of the first reference EXP of each frame in the TTI, and calculates this as the second reference EXP. (Step S113).

  Next, after the processing of step S112 or step S113, the second reference level determination unit 20 outputs the second reference EXP to the second normalization processing unit 21 (step S114).

  When turbo decoding of the max * -log-MAP algorithm is performed in a steep fading environment, the signal level of other sections is generally increased by a signal having a high level only in a short section by normalizing based on the average EXP. Can be prevented. When Viterbi decoding is performed, normalization can be performed on the basis of the optimum minimum EXP. Further, when they are mixed, normalization can be performed by selecting an optimum reference level for the priority encoding type determined by weighting according to RMA.

  FIG. 4 is a diagram illustrating a normalization process performed by the second normalization processing unit. FIG. 4A shows Symbol before normalization. In this example, 4 frames per 1 TTI (TTI = 40 msec) and 4 symbols per 1 frame are shown. FIG. 4B shows a state normalized with the minimum value of the first reference EXP as a reference. FIG. 4 (c) shows a state normalized with the average value of the first reference EXP as a reference.

  Referring to FIG. 4, when each Symbol having different Exponent values for each Symbol shown in (a) is normalized with respect to the minimum value of the first reference EXP, as shown in (b), the minimum The dynamic range of the symbol having the largest component (maximum reception level) is the largest, and the level of the other symbols is rounded in the smaller direction.

  Further, when normalized based on the average value of the first reference EXP, as shown in (c), the dynamic range of the symbol having the average reception level is the largest, and the symbol having the reception level exceeding the maximum is the maximum. The symbol having a reception level below that level is rounded in the smaller direction.

  When turbo decoding of the max * -log-MAP algorithm is performed in a steep fading environment, normalization is performed on the basis of the average value of the first reference EXP, so that a signal having a high level only in a short interval can be used to generate another interval. It is possible to prevent the signal level from becoming lower overall. When Viterbi decoding is performed, normalization can be performed based on the minimum value of the first reference EXP that is optimal for the Viterbi decoding. Further, when they are mixed, normalization can be performed by selecting an optimum reference level for the priority encoding type determined by weighting according to RMA.

  As described above, according to the CDMA receiver of the present embodiment, the first reference level determining unit 15 performs the Frame Exponent information and received TFCI information from the finger unit 12, the RMA information from the higher layer, and the encoding. Based on the type information, the first reference EXP optimum for normalization for each frame in the first normalization processing unit 16 is obtained in consideration of the TrCH multiplexed in the frame, and the second reference level determination unit 20 However, since the second reference EXP optimum for normalization for each TrCH in the second normalization processing unit 21 is obtained from the first reference EXP and the coding type information, linear Viterbi decoding and non-linear max * -When turbo decoding using the log-MAP algorithm coexists, optimal normalization is performed according to the encoding type without requiring complicated processing Bets can be, also it is possible to obtain good reception characteristics in the turbo decoding even under abrupt fading environment. Furthermore, in order to obtain good reception characteristics by optimal normalization, scaling with complicated decoding processing is not required.

  Here, an embodiment in which the present invention is applied to a receiver of a W-CDMA base station has been illustrated, but the present invention is not limited to this, and is applied to, for example, a receiver of a W-CDMA terminal apparatus. You can also

It is a block diagram which shows the structure of the CDMA receiver of one Embodiment of this invention. 3 is a flowchart showing the operation of first and second reference level determination units in the CDMA receiver shown in FIG. 1. It is a figure which shows the mode of the normalization process by a 1st normalization process part. It is a figure which shows the mode of the normalization process by a 2nd normalization process part. It is a block diagram which shows the structure of the conventional CDMA receiver. 6 is a flowchart showing operations of first and second reference level determination units in the conventional CDMA receiver shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Path search part 12 Finger part 13 Decoding part 14 Memory 15 1st reference level determination part 16 1st normalization process part 17 1st channel decoding part 18 Memory 19 TrCH process part 20 2nd reference level determination part 21 Second normalization processing unit 22 1st Deinterleave processing unit 23 Selector 24 Turbo decoding processing unit 25 Viterbi decoding processing unit 26 Second channel decoding units S101 to S105, S111 to S114 Steps

Claims (18)

A normalization method for normalizing a signal used for decoding processing in a receiving device capable of decoding processing of a plurality of encoding types having different reference values optimum for normalization,
A first step of determining an encoding type of a channel signal included in the received frame signal;
A second step of determining a priority coding type to be prioritized in normalization among the coding types of channel signals included in the frame signal using information from an upper layer;
A third step of determining a first reference value optimal for normalization in the priority encoding type;
And a fourth step of normalizing the frame signal using the first reference value. After the channel decoding process is performed on the frame signal normalized in the fourth step, the second reference value optimum for the coding type is determined for each channel signal included in the frame signal. A fifth step from the value;
6. The method according to claim 1, further comprising: a sixth step of normalizing the channel signal using the second reference value and then performing a decoding process appropriate for the encoding type on the channel signal. Normalization method. The normalization method according to claim 1, wherein the encoding types that can be decoded by the receiving apparatus include non-linear decoding processing and linear decoding processing encoding types. The normalization method according to claim 3, wherein the encoding type of the nonlinear decoding process is to perform turbo decoding using a max * -log-MAP algorithm. The normalization method according to claim 3 or 4, wherein an encoding type of the linear decoding process is Viterbi decoding. In the third step, if the decoding process of the priority coding type is non-linear, the first reference value is obtained from an average value of channel signals within a normalization unit, and the decoding process of the priority coding type The normalization method according to claim 3, wherein the first reference value is obtained from the maximum value of the channel signal within the normalization unit if is linear. In the second step, when the frame signal includes channel signals of a plurality of encoding types, the priority is weighted so as to give priority to the channel signal for which the QoS is relatively increased in the upper layer. The normalization method according to claim 2, wherein an encoding type is determined. The normalization method according to claim 7, wherein the channel signal is weighted using RMA information. In the first step, the encoding type of the channel signal included in the frame signal is grasped by the received TFCI information indicating the type of the channel signal multiplexed in the frame signal and the higher layer. The normalization method according to any one of claims 1 to 8, wherein the normalization method is discriminated from various types of encoding type information. A receiving apparatus capable of decoding a plurality of encoding types having different reference values optimal for normalization,
The channel signal encoding type included in the received frame signal is determined, and among the channel signal encoding types included in the frame signal, the priority encoding type to be prioritized in normalization is determined from the upper layer. First reference level determination means for determining a first reference value that is optimal for normalization in the priority encoding type,
And a first normalization processing unit that normalizes the frame signal using the first reference value. Channel decoding processing means for performing channel decoding processing on the frame signal normalized by the first normalizing means;
A second reference level for obtaining a second reference value optimum for the coding type from the first reference value for each channel signal included in the frame signal subjected to the channel decoding processing by the channel decoding processing means. A determination means;
Second normalizing means for normalizing the channel signal using the second reference value;
The receiving apparatus according to claim 10, further comprising: a decoding processing unit that performs a decoding process suitable for the type of encoding on the channel signal normalized by the second normalizing unit. The receiving device according to claim 10 or 11, wherein the encoding types that can be decoded by the receiving device include non-linear decoding processing and linear decoding processing encoding types. The receiving apparatus according to claim 12, wherein the encoding type of the nonlinear decoding process is to perform turbo decoding using a max * -log-MAP algorithm. The receiving apparatus according to claim 12 or 13, wherein an encoding type of the linear decoding process is Viterbi decoding. If the decoding process of the priority coding type is non-linear, the first reference level determining unit obtains the first reference value from an average value of channel signals within a normalization unit, and the priority coding type The receiving apparatus according to claim 12, wherein the first reference value is obtained from the maximum value of the channel signal in the normalization unit if the decoding process of is normal. The first reference level determination means weights the channel signal, which is intended to relatively increase the QoS in the upper layer, when the frame signal includes channel signals of a plurality of encoding types, to give priority to the channel signal. The receiving apparatus according to claim 11, wherein the priority encoding type is determined. The receiving apparatus according to claim 16, wherein the first reference level determination unit weights the channel signal using RMA information. The first reference level determination means includes a channel signal encoding type included in the frame signal, received TFCI information indicating the type of the channel signal multiplexed in the frame signal, and an upper layer. The receiving device according to any one of claims 10 to 17, wherein the receiving device is discriminated from the various types of encoding type information that are grasped.

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