JP2012109841A - Transmitter, receiver, transmission method and reception method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for compatibly suppressing the deterioration of reception characteristics and reducing a processing amount when using error correction coding.SOLUTION: A first coding part 50 generates a first parity from inputted information data, and a second coding part 54 generates a second parity from the inputted information data. As the operation of the first coding part 50 and the second coding part 54, at least a first mode and a second mode are stipulated and one of the modes is selected. A generation part 56 generates transmission data on the basis of the information data, the first parity and the second parity in the case of the first mode, and generates transmission data on the basis of the information data and the first parity in the case of the second mode. The first coding part 50 and the second coding part 54 are operated in the first mode, and the first coding part 50 is operated and the second coding part 54 is stopped in the second mode.

Description

  The present invention relates to communication technology, and in particular, to a transmission device, a reception device, a transmission method, and a reception method that execute encoding for error correction.

  In the wireless communication system, the signal-to-noise power ratio can be lowered due to the attenuation of the received signal level or the increase of the noise level due to the influence of fluctuation or attenuation of the wireless transmission path. In order to be able to decode the signal even with a low signal-to-noise power ratio, error correction coding techniques are used. An example of error correction coding is convolutional coding or turbo coding. Viterbi decoding is used to decode the convolutionally encoded data, and BCJR (Bahl Cocke Jelinek Raviv) decoding and Log-MAP decoding are used to decode the turbo encoded data. In order to control the transmission rate using such an error correction coding technique, for example, any one of a turbo code, a trellis code, and an information bit is selected and transmitted (Patent Document 1). That is, since a part of the data encoded according to the measured value of CNR (Carrier to Noise Ratio) is not output, the transmission rate is improved.

JP 2000-196471 A

  In wireless communication devices, particularly mobile stations, reduction of power consumption is desired. At that time, from the viewpoint of continuous communication time expansion, it is desirable to reduce the power as much as possible in addition to the reduction of the transmission output. On the other hand, it is also desired to optimize performance according to the communication path conditions. For this reason, it is required to satisfy both the suppression of the deterioration of the reception characteristics and the reduction of the processing amount. In the background art, since a circuit that generates unselected data is also operating, the amount of processing is not reduced. In addition, when block interleaving is performed after data is selected, the frame size changes due to a change in the coding rate, so that processing such as switching the block interleaver increases. In addition, it has been proposed to reduce the number of times of computation processing for decoding by changing the number of times of iterative decoding of turbo decoding according to the CNR measurement value for the received signal, but on the encoding side, the amount of processing is reduced. Not. Furthermore, although it has been proposed to change the modulation method and coding rate according to the CNR measurement value for the received signal, redundant processing increases in order to cope with changes in coding and modulation schemes.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a technique for achieving both reduction in reception characteristics and reduction in processing amount when error correction coding is used. It is to provide.

  In order to solve the above problems, a transmission device according to an aspect of the present invention includes an input unit that inputs information data to be transmitted, and an encoding process performed on the information data input in the input unit. A first encoding unit that generates 1 parity, a second encoding unit that generates a second parity by sequentially performing interleaving processing and encoding processing on the information data input in the input unit; As operations of the first encoding unit and the second encoding unit, at least the first mode and the second mode are defined, and when the control unit selects one of the modes and the control unit selects the first mode, Transmission data is generated based on the information data input in the input unit, the first parity generated in the first encoding unit, and the second parity generated in the second encoding unit, and the control unit generates the second mode. When you select the information data inputted in the input unit, based on the first parity has been generated by the first encoding unit, and a generation unit for generating transmission data. The control unit operates the first encoding unit and the second encoding unit during the first mode, and operates the first encoding unit and stops the second encoding unit during the second mode. Let

  According to this aspect, the first encoding unit and the second encoding unit are operated in the first mode, and the first encoding unit is operated in the second mode to operate the second encoding unit. Since it is stopped, the processing amount can be reduced in the second mode.

  The control unit further defines the third mode and selects the third mode when retransmitting the transmission data generated by the generation unit in the second mode, and the generation unit selects the third mode. If selected, retransmission data is generated based on the information data input in the input unit and the second parity generated in the second encoding unit. The first encoding unit is controlled by the control unit. When the 3 mode is selected, it may be stopped. In this case, if retransmission occurs in the second mode, the second parity that is not transmitted in the second mode is included in the retransmission target, so that deterioration of reception characteristics can be suppressed.

  Another aspect of the present invention is a receiving device. In the first mode, this apparatus generates information data, a first parity generated by encoding the information data, and an encoding process after interleaving the information data. A reception unit that receives reception data that includes the second parity and receives information data and reception data that includes the first parity in the second mode, and reception data received by the reception unit. The first decoding unit that generates the first decoded data by executing the decoding process, and the interleaving process and the decoding on the information data of the received data and the first decoded data generated in the first decoding unit By executing the processing and the deinterleaving process in order, the second decoding unit that generates the second decoded data and the received data received by the receiving unit are in the first mode. When the second decoding data generated by the second decoding unit is output as information data and the reception data received by the receiving unit is compatible with the second mode, the second decoding unit And a selection unit that outputs the first decoded data generated in the first decoding unit as information data.

  According to this aspect, the first decoding unit and the second decoding unit are operated in the first mode, and the second decoding unit is stopped by operating the first decoding unit in the second mode. The processing amount can be reduced in the second mode.

  When the reception data in the second mode is incorrect, the reception unit sets the information data and the second parity generated by performing the coding process after interleaving the information data as the third mode. Receiving the received data included, the second decoding unit, when the reception data received in the reception unit is compatible with the third mode, interleaving processing, decoding processing on the reception data generated in the reception unit, By executing the deinterleaving process in order, the second decoded data is generated, and the selection unit stops the first decoding unit when the reception data received by the receiving unit corresponds to the third mode. The second decoded data generated in the second decoding unit may be output as information data. In this case, if retransmission occurs in the second mode, the second decoding unit that is not used in the second mode is used, so that there is room for suppressing deterioration in reception characteristics.

  And a generator that generates new reception data based on the reception data in the second mode and the reception data in the third mode when the reception data in the third mode is incorrect. May be. The first decoding unit generates the first decoded data by executing a decoding process on the new reception data generated in the generation unit when the reception data in the third mode is incorrect, The second decoding unit sequentially executes an interleaving process, a decoding process, and a deinterleaving process on the first decoded data generated in the first decoding unit when the received data in the third mode is incorrect. To generate second decoded data, and the selection unit may output the second decoded data generated in the second decoding unit as information data when the received data in the third mode is incorrect. Good. In this case, if the received data in the third mode is incorrect, new received data is generated and decoded based on the received data in the second mode and the received data in the third mode. Since the process is executed, it is possible to suppress deterioration in transmission efficiency while suppressing deterioration in reception characteristics.

  Yet another embodiment of the present invention is a transmission method. This method includes a step of inputting information data to be transmitted, a step of generating a first parity by performing an encoding process on the input information data, and an interleaving process on the input information data The operations of generating the second parity, generating the first parity, and generating the second parity by executing the encoding process in order are at least the first mode and the second mode. And selecting one of the modes, and when the selecting step selects the first mode, based on the input information data, the generated first parity, and the generated second parity, Based on the input information data and the generated first parity when the step of generating and selecting the transmission data selects the second mode. And generating a transmission data. The step of selecting operates the step of generating the first parity and the step of generating the second parity in the first mode, and the step of generating the first parity in the second mode. The step of generating and generating the second parity is stopped.

  Yet another embodiment of the present invention is a reception method. In this method, in the first mode, the information data, the first parity generated by encoding the information data, and the encoding process after interleaving the information data are generated. Receiving the received data including the second parity, and receiving the received data including the information data and the first parity in the second mode; and performing a decoding process on the received received data By executing the step of generating the first decoded data, and sequentially performing the interleaving process, the decoding process, and the deinterleaving process on the information data of the received data and the generated first decoded data, A step of generating the second decoded data, and the generated second decoded data when the received data received corresponds to the first mode. A step of outputting the first decoded data as information data, stopping the step of generating the second decoded data when the received data corresponding to the second mode is output as the information data And comprising.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, when error correction coding is used, it is possible to achieve both suppression of deterioration of reception characteristics and reduction of processing amount.

It is a figure which shows the structure of the transmitter which concerns on Example 1 of this invention. It is a figure which shows the structure of the receiver which concerns on Example 1 of this invention. FIGS. 3A to 3B are diagrams illustrating the configuration of the encoding unit in FIG. FIGS. 4A to 4C are diagrams showing an outline of the operation of the encoding unit in FIGS. FIGS. 5A to 5B are diagrams illustrating the configuration of the decoding unit in FIG. FIGS. 6A to 6C are diagrams illustrating an operation outline of the decoding unit in FIGS. 5A to 5B. It is a flowchart which shows the transmission procedure in the transmitter of FIG. It is a flowchart which shows the reception procedure in the receiver of FIG. It is a flowchart which shows the encoding procedure in the encoding part of Fig.3 (a)-(b). It is a flowchart which shows the decoding procedure in the decoding part of Fig.5 (a)-(b). It is a figure which shows the structure of the encoding part which concerns on Example 2 of this invention. 12A to 12D are diagrams illustrating the configuration of the decoding unit according to the second embodiment of the present invention. It is a flowchart which shows the encoding procedure in the encoding part of Fig.3 (a)-(b) and FIG. It is a flowchart which shows the decoding procedure in the decoding part of Fig.12 (a)-(d).

Example 1
Before describing the present invention specifically, an outline will be given first. Embodiment 1 of the present invention relates to a wireless communication system including a transmission device that transmits a packet signal that has been subjected to error correction coding and a reception device that receives the packet signal. Here, turbo coding is assumed as error correction coding. In turbo encoding, parity (hereinafter referred to as “first parity”) is generated by encoding information data, and the parity (hereinafter referred to as “second”) is encoded after interleaving processing is performed on the information data. Parity ”). Further, the information data, the first parity, and the second parity are output as one unit. In turbo coding and decoding, it is desired to reduce the amount of processing while suppressing deterioration of reception characteristics. In order to cope with this, the communication system according to the present embodiment executes the following processing.

  When the communication channel is in a normal state (hereinafter referred to as “first case”), the transmission device transmits a signal in which the information data, the first parity, and the second parity are collected by executing turbo coding. To do. On the other hand, the receiving apparatus repeatedly executes a cyclic decoding process by the two decoding units. On the other hand, when the communication path is in a good state (hereinafter referred to as “second case”), the transmission apparatus stops the generation of the second parity and transmits a signal in which the information data and the first parity are collected. At that time, the receiving apparatus operates only one of the two decoding units to execute the decoding process. In this way, the transmitting device and the receiving device partially operate the circuit and stop the rest. In this transmission apparatus, the frame size, which is a transmission / reception unit, is the same in any case. Since the frame size is constant, the processing of the transmission device and the reception device is simplified.

  FIG. 1 shows a configuration of a transmission apparatus 100 according to Embodiment 1 of the present invention. The transmission apparatus 100 includes an information data generation unit 10, an encoding unit 12, a block interleave unit 14, a modulation unit 16, an RF / amplification unit 18, and a control unit 20.

  The information data generation unit 10 acquires data to be transmitted and generates information data. Here, transmission encoded information is added to the information data. The transmission coding information is information relating to coding that should be used by the receiving device that is the transmission source when a signal is transmitted in the direction opposite to the direction from the transmitting device 100 to the receiving device (not shown). The transmission encoding information is determined according to the state of the communication path between the transmission device 100 and the reception device, that is, whether the transmission is in the first case or the second case. Here, it is assumed that the encoding process and the decoding process in the first case are “first mode”, and the encoding process and the decoding process in the second case are “second mode”. That is, the transmission encoded information can be said to be information for instructing use of the first mode or use of the second mode. A process for determining transmission encoding information will be described later. The acquired data may be used as information data as it is, or information data may be generated by adding a CRC (Cyclic Redundancy Check) bit. The information data generation unit 10 outputs information data to the encoding unit 12.

  The encoding unit 12 receives the information data from the information data generation unit 10. The encoding unit 12 performs an encoding process and a puncture process on the information data. At that time, the encoding unit 12 inputs an instruction on whether to use the first mode or the second mode from the control unit 20, and executes an encoding process or the like according to the instruction. Here, the contents of the instruction are determined by a receiving device (not shown) and received by being included in the received encoded information. Details of the encoding process and the puncturing process will be described later. The encoding unit 12 outputs the encoded information data (hereinafter referred to as “encoded data”) to the block interleaving unit 14.

  The block interleave unit 14 develops one frame on a row × column size memory for the purpose of burst error reduction, and executes, for example, a process of writing in a row order and reading in a column order, thereby arranging the order of encoded data. Change. The encoded data in which the order is rearranged is also referred to as “encoded data”. The block interleave unit 14 outputs the encoded data to the modulation unit 16. The modulation unit 16 receives the encoded data from the block interleaving unit 14. The modulation unit 16 modulates the encoded data. As a modulation method, PSK (Phase Shift Keying), FSK (Frequency Shift Keying), or the like is used. The modulation unit 16 outputs the modulated encoded data (hereinafter referred to as “modulation data”) to the RF / amplification unit 18.

  The RF / amplifier 18 receives the modulation data from the modulator 16. The RF / amplifying unit 18 generates transmission data by performing frequency conversion to radio frequency, amplification, and the like on the modulated data. The RF / amplifier 18 transmits transmission data from the antenna. Here, the information data, the encoded data, the modulation data, and the transmission data may have a packet signal format. The control unit 20 controls the timing of the entire transmission device 100 and the like. The control unit 20 acquires received encoded information from a receiving device (not shown). As described above, the received encoded information includes an instruction for selecting the first mode or the second mode. The control unit 20 outputs the received encoded information to the encoding unit 12 to instruct the encoding unit 12 to use the first mode or the second mode.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it can be realized by a program loaded in the memory, but here it is realized by their cooperation. Draw functional blocks. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  FIG. 2 shows the configuration of the receiving apparatus 200 according to Embodiment 1 of the present invention. The receiving apparatus 200 includes an amplification / RF unit 30, a demodulation unit 32, a block deinterleave unit 34, a decoding unit 36, a data processing unit 38, a communication path estimation unit 40, and a control unit 42.

  The amplification / RF unit 30 receives a packet signal from the transmission device 100 (not shown), that is, transmission data, via the antenna. It is assumed that a training signal is placed at the beginning of the packet signal. The training signal is a signal known to the receiving device 200. The amplification / RF unit 30 performs amplification, frequency conversion to an intermediate frequency, etc., on the packet signal, and outputs the result (hereinafter also referred to as “packet signal”) to the demodulation unit 32. The demodulator 32 receives the packet signal from the amplifier / RF unit 30. The demodulator 32 demodulates the packet signal. The demodulator 32 uses the training signal arranged at the beginning of the packet signal at the time of demodulation. Demodulator 32 outputs the demodulated packet signal (hereinafter referred to as “demodulated data”) to block deinterleaver 34. Further, the demodulation unit 32 outputs the received training signal to the communication path estimation unit 40.

  The communication path estimation unit 40 receives the training signal from the demodulation unit 32. The communication channel estimation unit 40 performs communication channel estimation based on the training signal. As for channel estimation, there are a method for estimating channel characteristics from a carrier power-to-noise power ratio estimation pattern included in a received signal and a method for measuring channel characteristics from RSSI (Received Signal Strength Indicator). . Here, since a known technique may be used for channel estimation, description thereof is omitted. The channel estimation unit 40 presets a threshold for the estimation result, and determines whether the channel status is normal or good by comparing the estimation result with the threshold. This corresponds to determining the first case and the second case. The communication path estimation unit 40 outputs the determination result to the control unit 42.

  The block deinterleave unit 34 inputs the demodulated data from the demodulator 32. The block deinterleaving unit 34 performs a process for returning the order of the demodulated data by performing a process opposite to that performed by the block interleaving unit 14 of FIG. 1 on the demodulated data. The block deinterleave unit 34 outputs the demodulated data whose order has been restored (hereinafter also referred to as “demodulated data”) to the decoding unit 36.

  The decoding unit 36 receives the demodulated data from the block deinterleaving unit 34. The decoding unit 36 inputs an instruction according to received encoded information from the control unit 42 described later, and executes a decoding process according to the instruction. If the instruction is to use the first mode, the decoding unit 36 executes the decoding process in the first mode. If the instruction is to use the second mode, the decoding unit 36 executes the decoding process in the second mode. To do. The decryption unit 36 outputs the decryption result (hereinafter referred to as “decoded data”) to the data processing unit 38.

  The data processing unit 38 inputs the decoded data from the decoding unit 36. The data processing unit 38 performs a predetermined process on the decoded data and outputs the result as information data. As the predetermined processing, for example, CRC detection is performed and reception encoded information is extracted. The data processing unit 38 outputs the extracted transmission encoded information to the control unit 42.

  The control unit 42 controls the timing of the entire receiving device 200 and the like. The control unit 42 receives the determination result from the communication path estimation unit 40 and generates reception encoded information based on the determination result. For example, if the determination result is the first case, the control unit 42 determines the use of the first mode as the determination result, and if the determination result is the second case, the control unit 42 determines the use of the second mode. Determined as a determination result. After receiving encoded information is transmitted from the receiving apparatus 200 to the transmitting apparatus 100, when the receiving apparatus 200 receives from the transmitting apparatus 100 a packet signal that has been encoded according to the received encoded information, When decoding the packet signal, the reception encoding information is output to the decoding unit 36.

  FIGS. 3A and 3B show the configuration of the encoding unit 12. FIG. 3A is a configuration for explaining a portion of the encoding unit 12 that operates in the first case. This corresponds to the first mode. The encoding unit 12 includes a first encoding unit 50, an interleave unit 52, a second encoding unit 54, and a generation unit 56. The encoding unit 12 performs normal turbo encoding processing as the first mode.

  The encoding unit 12 inputs information data to be transmitted from the information data generation unit 10 of FIG. The first encoding unit 50 generates a first parity by performing an encoding process on the input information data. At that time, the order of the information data is not changed. The first encoding unit 50 outputs the first parity to the generation unit 56. The interleaving unit 52 changes the order of the information data by executing an interleaving process on the information data. It is assumed that the interleave pattern is determined in advance. The interleaving unit 52 outputs the information data whose order has been changed to the second encoding unit 54.

  The 2nd encoding part 54 produces | generates a 2nd parity by performing an encoding process in order with respect to the information data which changed the order in the interleaving part 52. FIG. The second encoding unit 54 outputs the second parity to the generation unit 56. The generation unit 56 combines the directly input information data, the first parity from the first encoding unit 50, and the second parity from the second encoding unit 54. At that time, the generation unit 56 performs puncturing in accordance with a necessary rate. The generation unit 56 outputs the processing result as encoded data.

  FIG. 3B is a configuration for explaining a portion of the encoding unit 12 that operates in the second case. This corresponds to the second mode. The encoding unit 12 includes a first encoding unit 50 and a generation unit 56. As illustrated, in the second mode, the interleave unit 52 and the second encoding unit 54 are stopped by turning off the power or operating in the power save mode. In addition, the generation unit 56 combines the directly input information data and the first parity from the first encoding unit 50 in the second mode. The generation unit 56 outputs the processing result as encoded data. That is, in the second mode, the encoding unit 12 executes only a part of the normal turbo encoding process.

  Here, the operation of the encoding unit 12 will be described with a specific example. 4A to 4C show an outline of the operation of the encoding unit 12. However, for the sake of clarity, the description of the operation of the interleaving unit 52 is omitted, but the actual operation is only the order of input to the second encoding unit 54 is different. FIG. 4A shows an operation in the first mode and when the puncturing process is not performed in the generation unit 56 in FIG. Information data dk = {d0, d1, d2, d3,...} Is input at time k = {0, 1, 2, 3,. In response to this, the first encoder 50 outputs p1k = {p10, p11, p12, p13,...}, And the second encoder 54 outputs p2k = {p20, p21, p22,. p23,...} are output. The generation unit 56 outputs mout_k = {(d0, p10, p20), (d1, p11, p21), (d2, p12, p22),. Here, a combination enclosed in parentheses indicates information data and parity for the information data.

  FIG. 4B shows an operation when the puncturing process is performed in the generation mode 56 of FIG. 3A in the first mode. The generation unit 56 alternately performs puncture processing on the first parity from the first encoding unit 50 and the second parity from the second encoding unit 54. As a result, the generation unit 56 outputs mout_k = {(d0, p10), (d1, p21), (d2, p12,),. FIG. 4C shows the operation in the second mode. At that time, the second parity is not generated. The generation unit 56 outputs mout′_k = {(d0, p10), (d1, p11), (d2, p12),. In this case, the operation of the first encoding unit 50 is the same as that in the case of FIG. 4B, and the rate of the encoded data that is the output from the generation unit 56 does not change.

  5A to 5B show the configuration of the decoding unit 36. FIG. FIG. 5A is a configuration for explaining a portion of the decoding unit 36 that operates in the first case. The decoding unit 36 includes a depuncturing unit 60, a first decoding unit 62, a second decoding unit 64, a selection unit 66, and a hard decision unit 68. The second decoding unit 64 includes an interleaving unit 70, a processing unit 72, a deinterleaving unit. 74. This corresponds to the first mode. The decoding unit 36 performs normal turbo decoding processing as the first mode.

  Here, before explaining the process of FIG. 5A, a normal turbo decoding process will be explained. The value acquired by each decoding unit is the log likelihood ratio → the posterior value, and in order to be used as information by the next decoding unit, conversion to a prior value and data rearrangement are required. In addition, when the number of memory stages in configuring the encoding unit 12 is m, 2m states can be taken as the memory state. These states are called “states”, and at the time of decoding, which state is likely to be taken is calculated from the sum of the previous and subsequent probabilities for each time and the reception result at that time. Each decoding unit executes probability calculation for each time and each state (α calculation, integration before that time) in the forward direction from the start to the end, provided that the start and end of the frame are state 0 To do. Each decoding unit executes probability calculation (β calculation, integration after that time) for each time and each state in the reverse direction from the end to the start. Furthermore, each decoding unit executes a transition probability calculation (γ calculation, between two times) for each state at the next time at each time. After that, each decoding unit derives a log likelihood ratio (Λ) by calculating a product α * γ * β of three pieces of information from the beginning to the end of the frame.

This is based on BCJR decoding, but there are many exponential operations and the amount of operations itself is large. Therefore, the maximum value at each time is searched for the logarithm of the three pieces of information α, γ, and β (MAX-Log-MAP decoding), a correction operation is added to it (Log-MAP decoding), and backward calculation is performed. (Β) may be omitted (SOVA decoding). Note that in BCJR decoding and Log-MAP decoding, a CNR indicating the state of the transmission path is required.

  The depuncture unit 60 inputs the demodulated data from the block deinterleave unit 34 in FIG. Demodulated data includes information data, a first parity generated by encoding the information data, and a second parity generated by encoding the information data after interleaving. Yes. The depuncture unit 60 inserts data corresponding to a threshold value into the demodulated data at the timing thinned out by the generation unit 56 in FIG. The depuncture unit 60 outputs the depunctured demodulated data to the first decoding unit 62 and the interleave unit 70.

  The first decoding unit 62 receives the depunctured demodulated data from the depuncturing unit 60 and the prior value La1 (dk) (however, the initial value is 0) from the deinterleaving unit 74. The first decoding unit 62 derives the posterior value Le1 (dk) by a known technique. This corresponds to a decoding process. The first decoding unit 62 outputs the posterior value Le1 (dk) to the interleaving unit 70. The interleaving unit 70 receives the depunctured demodulated data from the depuncturing unit 60 and the posterior value Le1 (dk) from the first decoding unit 62. The interleaving unit 70 changes the order of the demodulated data {R ′ (dk), R (pn)} and the a posteriori value Le1 (dk) by interleaving, and the demodulated data {R (dn), R (pn)} The value La2 (dn) is generated. Interleaving unit 70 outputs demodulated data {R (dn), R (pn)} and prior value La2 (dn) to processing unit 72.

  The processing unit 72 inputs the demodulated data {R (dn), R (pn)} and the prior value La2 (dn) from the interleaving unit 70. The processing unit 72 derives the posterior value Le2 (dn) and the log likelihood ratio Λ (dn) by a known technique. This corresponds to a decoding process. The processing unit 72 outputs the posterior value Le2 (dn) and the log likelihood ratio Λ (dn) to the deinterleaving unit 74. The deinterleaving unit 74 receives the posterior value Le2 (dn) and the log likelihood ratio Λ (dn) from the processing unit 72. The deinterleaving unit 74 derives the prior value La1 (dk) by the deinterleaving process, and outputs the prior value La1 (dk) to the first decoding unit 62.

  This “first decoding unit 62 operation → second decoding unit 64 operation” is performed once, and for the second and subsequent decodings, the processing result of the second decoding unit 64 is output to the first decoding unit 62 as the next information. Let's start by. After repeating the decoding up to a predetermined number of times, the selection unit 66 outputs Λ (dk) from the deinterleaving unit 74 to the hard decision unit 68. The hard decision unit 68 receives the log likelihood ratio Λ (dk) from the selection unit 66 and makes a hard decision. The hard decision unit 68 outputs the hard decision result as decoded data.

  FIG. 5B is a configuration for explaining a portion of the decoding unit 36 that operates in the second case. The decoding unit 36 includes a depuncture unit 60, a first decoding unit 62, a selection unit 66, and a hard decision unit 68. The depuncture unit 60 inputs the demodulated data from the block deinterleave unit 34 in FIG. In the second mode, the demodulated data includes information data and first parity, and does not include second parity. As illustrated, in the second mode, the second decoding unit 64 is stopped by turning off the power or operating in the power save mode. The first decoding unit 62 outputs the log likelihood ratio Λ (dk) as a decoding result to the selection unit 66, and the selection unit 66 outputs the log likelihood ratio Λ (dk) to the hard decision unit 68. At that time, the repetitive processing as in the first mode is not performed. The hard decision unit 68 receives the log likelihood ratio Λ (dk) from the selection unit 66 and makes a hard decision. That is, in the second mode, the decoding unit 36 executes only a part of normal turbo decoding processing.

  Here, the operation of the decoding unit 36 will be described with a specific example. 6A to 6C show an outline of the operation of the decoding unit 36. FIG. It is assumed that the puncturing process in the encoding unit 12 is performed only in the first mode as described above. Here, as in the description of the encoding unit 12, the description of the operations of the interleaving unit 70 and the deinterleaving unit 74 is omitted. FIG. 6A shows the operation in the first mode and when the encoding unit 12 has not been punctured. Here, at time k = {0, 1, 2, 3,...}, The received word xk = {x0, {x0, {d0, d1, d2, d3,. x1, x2, x3,... Further, the received word y1k = {y10, y11, y12, y13,...} For the first parity p1k = {p10, p11, p12, p13,. Further, the received word y2k = {y20, y21, y22, y23,...} For the second parity p2k = {p20, p21, p22, p23,. The first decoding unit 62 receives a combination of xk and y1k, and the processing unit 72 receives a combination of xk and y2k.

  FIG. 6B shows an operation in the first mode and when the encoding unit 12 is punctured. Since some data is thinned out by the puncture processing, it is necessary to fill the data in an “undefined” state at the time of decoding, and this operation is the depuncture processing in the depuncture unit 60 of FIG. If the binary data ± 1 is an expected value with respect to the demodulated data, an intermediate value “0” is inserted as an indefinite value. As illustrated, “0” is inserted into y1k and y2k in accordance with the pattern of the puncture process. FIG. 6C shows the operation in the second mode. As described above, since the second parity is not generated, there is no data to be input to the processing unit 72. Therefore, the second decoding unit 64 is not involved in the decoding process. On the other hand, the depuncture process is not performed on the data input to the first decoding unit 62. In this case, the first decoding unit 62 performs the decoding process as in the first mode. However, since the decoding iterative process is not performed, the prior value La1 (dk) from the deinterleaving unit 74 is not input to the first decoding unit 62.

  The operation of the communication system having the above configuration will be described. FIG. 7 is a flowchart showing a transmission procedure in the transmission apparatus 100. If there is no reception result, such as at the time of the first transmission, the communication path is not estimated. Therefore, when there is no transmission coding information (N in S10), the transmission coding information is set to the first mode (S14). On the other hand, when there is transmission encoded information (Y in S10), transmission encoded information is generated according to the result at the time of reception (S12). The information data generation unit 10 generates information data so as to include transmission encoded information (S16). When there is received encoded information from the receiving apparatus 200 (Y in S18), the control unit 20 sets a control signal based on the received encoded information (S20). When there is no reception encoding information from the receiving apparatus 200 (N in S18), the control unit 20 sets the control signal to use the first mode (S22). The encoding unit 12 sets a mode according to the control signal and executes an encoding process (S24).

  FIG. 8 is a flowchart showing a receiving procedure in receiving apparatus 200. If the transmission encoded information has not been transmitted to the transmission device 100 (N in S40), the control unit 42 sets the control signal to use the first mode (S42). If the transmission encoded information has been transmitted to the transmission device 100 (Y in S40), the control unit 42 sets the transmitted transmission encoded information in the control signal (S44). The decoding unit 36 performs a decoding process according to the control signal from the control unit 42 (S46). The data processing unit 38 acquires received encoded information from the decoding result (S48). If the estimation result of the communication channel is good in the communication channel estimation unit 40 (Y in S50), the control unit 42 sets the reception encoding information to use the second mode (S52). If the estimation result of the communication channel is not good in the communication channel estimation unit 40 (N in S50), the control unit 42 sets the reception encoded information to use the first mode (S54).

  FIG. 9 is a flowchart showing an encoding procedure in the encoding unit 12. The control unit 20 acquires received encoded information (S70). The first encoding unit 50 performs an encoding process (S72). When the use of the first mode is indicated by the received encoded information (Y in S74), the second encoding unit 54 executes an encoding process (S76). The generation unit 56 selects puncture processing for the first mode (S78). When the use of the first mode is not indicated by the received encoded information (N in S74), the generation unit 56 selects the puncture process for the second mode (S80). Here, it is assumed that the puncturing process is not executed in the second mode. The generation unit 56 performs puncture processing (S82).

  FIG. 10 is a flowchart showing a decoding procedure in the decoding unit 36. The control unit 42 acquires transmission encoded information (S100). When the transmission encoded information is not transmitted or the first mode is designated (Y in S102), the depuncture unit 60 selects the depuncture process for the first mode (S104). On the other hand, if the first mode is not designated (N in S102), the depuncture unit 60 selects the depuncture process for the second mode (S106). Here, it is assumed that the depuncture process is not executed in the second mode. The depuncture unit 60 performs a depuncture process (S108). Initialization processing for decoding processing is executed (S110). The 1st decoding part 62 performs a decoding process (S112). If the first mode is designated (Y in S114), the interleaving unit 70 executes an interleaving process (S116).

  The processing unit 72 executes a decoding process (S118). If the number of iterations has not reached the specified number (N in S120), the deinterleaving unit 74 performs deinterleaving on the posterior value (S122), and returns to Step 112. If the number of iterations reaches the specified number (Y in S120), the deinterleaving unit 74 executes the deinterleaving process on the log likelihood ratio (S124), and the hard decision unit 68 executes the hard decision. (S126). If the first mode is not designated (N in S114), the hard decision unit 68 performs a hard decision (S126).

  According to the embodiment of the present invention, the first encoding unit and the second encoding unit are operated in the first mode, and the first encoding unit is operated in the second mode to operate the second mode. Since the encoding unit is stopped, the processing amount can be reduced in the second mode. Further, since it is only necessary to change whether the second encoding unit is operated or stopped depending on whether the mode is the first mode or the second mode, the processing can be simplified. Further, regardless of whether the mode is the first mode or the second mode, the amount of information data included in the packet signal does not fluctuate, so that the processing can be simplified.

  In the first mode, the first decoding unit and the second decoding unit are operated, and in the second mode, the first decoding unit is operated and the second decoding unit is stopped. In this case, the processing amount can be reduced. Further, since it is only necessary to change whether to operate or stop the second decoding unit depending on whether the mode is the first mode or the second mode, the processing can be simplified. In addition, when the communication channel is in good condition, one of the two encoding units and one of the two decoding units in turbo encoding are not used, so that power consumption can be reduced. Further, since the bit allocation of the second puncture is reassigned to the first puncture without changing the modulation scheme and the coding rate, the processing can be simplified.

(Example 2)
As in the first embodiment, the second embodiment of the present invention relates to a communication system that supports turbo codes. The transmission device and the reception device execute only a part of the turbo coding and turbo decoding when the communication path is in a good state. In the second embodiment, retransmission of transmission data is further considered. In an automatic repeat request (ARQ: Automatic Repeat reQuest), when the bit error rate in the receiving apparatus does not satisfy a predetermined value, or when an error is detected in the CRC, the receiving apparatus requests the transmitting apparatus to retransmit, The transmission device transmits the same transmission data again in response to this request. If an error occurs when using the second mode in the first embodiment, if retransmission is performed in the same second mode, there is a high possibility that the error will occur again.

  When retransmitting with HARQ Type I, if the previous received value is discarded, there is no increase in redundancy. For this reason, when the Doppler frequency is lower than the packet signal size in a fading environment, most of the frame is damaged, and improvement is difficult unless the reception status changes. In addition, HARQ Type II is configured to increase redundancy when retransmitting. However, if information data is not retransmitted, the subsequent decoding result is greatly influenced by the reception result of the first information data. Become. For this reason, even when retransmission occurs, it is desired to suppress both deterioration in reception characteristics and reduce the processing amount.

  When an error occurs in the packet signal transmitted in the second mode (hereinafter referred to as “third case”), the transmitting apparatus is not the first encoding unit that has already been used, but the second encoding that is not being used. The packet signal is generated again using only the part. It is assumed that the encoding process and the decoding process in the third case are the “third mode”. The transmitting apparatus retransmits the packet signal generated again. The receiving device acquires information data by performing demodulation processing and decoding processing on the retransmitted packet signal. When an error also occurs in the retransmitted packet signal (hereinafter referred to as “fourth case”), the receiving apparatus sets the log likelihood ratio based on the first received packet signal and the retransmitted packet signal. In response, a new packet signal is generated internally. The receiving device performs a decoding process on the new packet signal. It is assumed that the decoding process in the fourth case is the “fourth mode”. The transmission device 100 according to the second embodiment is the same type as that in FIG. 1, and the reception device 200 according to the second embodiment is the same type as that in FIG. Therefore, here, the difference will be mainly described.

  The configuration of the encoding unit 12 is the same type as that in FIG. Therefore, FIG. 3A shows a portion where the encoder 12 operates in the first mode, and FIG. 3B shows a portion where the encoder 12 operates in the second mode. Hereinafter, the process of the encoding unit 12 in the case of the third case, that is, the third mode will be described. The control unit 20 in FIG. 1 further defines the third mode, and selects the third mode when retransmitting the transmission data transmitted in the second mode. The occurrence of retransmission is detected by receiving NACK (Negative ACKnowledge) from receiving apparatus 200. The control unit 20 instructs the encoding unit 12 to select the third mode.

  FIG. 11 shows the configuration of the encoding unit 12 according to the second embodiment of the present invention. FIG. 11 corresponds to a portion where the encoding unit 12 operates in the case of the third mode. The encoding unit 12 includes an interleave unit 52, a second encoding unit 54, and a generation unit 56. The interleaving unit 52 and the second encoding unit 54 that have stopped operating in the second mode start operating when in the third mode. As a result, the interleaving unit 52 and the second encoding unit 54 generate the second parity from the information data to be retransmitted. The second encoding unit 54 outputs the second parity to the generation unit 56. The generation unit 56 combines the directly input information data and the second parity from the second encoding unit 54 in the third mode. The generation unit 56 outputs the processing result as encoded data for retransmission. In addition, the 1st encoding part 50 which is not shown in figure stops in the case of a 3rd mode. That is, in the third mode, the encoding unit 12 executes only a part of the normal turbo encoding process and is different from that in the second mode.

  12A to 12D show the configuration of the decoding unit 36 according to the second embodiment of the present invention. FIG. 12A is a configuration for explaining a portion operating in the first case in the decoding unit 36. The configuration of FIG. 12A is the same type as the configuration of FIG. 5A, but a first memory 80 and a second memory 82 are added. The first memory 80 and the second memory 82 may be included in the configuration of FIG. FIG. 12B is a configuration for explaining a portion of the decoding unit 36 that operates in the second case. The configuration of FIG. 12B is the same type as the configuration of FIG. 5B, but a first memory 80 and a fourth memory 86 are added. Note that the first memory 80 and the fourth memory 86 may be included in the configuration of FIG.

  The first memory 80 receives the depunctured demodulated data from the depuncture unit 60. The first memory 80 stores the depunctured demodulated data. That is, in the first memory 80, the sequence {R ′ (dk)} corresponding to the information data of the demodulated data and the sequence {R (p1k)} corresponding to the first parity are developed. Since 2 parities are not included, {R (p1k)} = {Rp}. Note that storage is performed over packet signals. The fourth memory 86 receives the log likelihood ratio {Λ (dk)} from the first decoding unit 62. The fourth memory 86 stores the log likelihood ratio {Λ (dk)}. Note that storage is performed over packet signals.

  FIG. 12C is a configuration for explaining a portion of the decoding unit 36 that operates in the third case. FIG. 12C includes a depuncturing unit 60, a third memory 84, a second decoding unit 64, a second memory 82, a selection unit 66, and a hard decision unit 68. The second decoding unit 64 includes an interleaving unit 70, processing Part 72 and deinterleave part 74. At that time, the first memory 80 and the fourth memory 86 in FIG. 12B hold the stored contents. This corresponds to storing the received content at the time of the first transmission and the decoding operation result of the first decoding unit in the second case operation.

  The depuncture unit 60 inputs information data and demodulated data including a second parity generated by performing an interleaving process on the information data and then performing an encoding process. In the third mode, the depuncture unit 60 does not execute the depuncture process. The third memory 84 stores demodulated data. In the third memory 84, a sequence {Rr '(dk)} corresponding to the information data of the demodulated data and a sequence {R (p2n)} corresponding to the second parity are developed. Note that storage is performed over packet signals. The interleaving unit 70 generates a sequence {Rr (dn)} by performing an interleaving process on the sequence {Rr ′ (dk)} corresponding to the information data in the third mode.

  In the third mode, the processing unit 72 performs a decoding process on the sequence {Rr (dn)} and the sequence {R (p2n)} corresponding to the second parity. Here, the processing of the processing unit 72 is the same as that in mode 1, but the iterative decoding is not executed and the log likelihood ratio {Λr (dn)} is output to the deinterleaving unit 74. The deinterleaving unit 74 performs deinterleaving processing. The second memory 82 stores the log likelihood ratio {Λr (dk)} of the deinterleave result. Note that storage is performed over packet signals. In the third mode, the selection unit 66 selects the log likelihood ratio {Λr (dk)} stored in the second memory 82 and sends the log likelihood ratio {Λr (dk)} to the hard decision unit 68. Output. In the third mode, the first decoding unit 62 is stopped.

  FIG. 12D is a configuration for explaining a portion of the decoding unit 36 that operates when there is an error in the result of decoding in the third mode (hereinafter referred to as “fourth case”). As a premise, the data processing unit 38 in FIG. 2 performs CRC detection on the decoded data output from the decoding unit 36 in the third mode. When an error is detected, the control unit 42 instructs the decoding unit 36 to operate in the fourth mode. FIG. 12D shows a first memory 80, a third memory 84, a first decoding unit 62, a second decoding unit 64, a second memory 82, a fourth memory 86, an absolute value comparison unit 88, a selection unit 66, a hard unit. The determination unit 68 is included, and the second decoding unit 64 includes an interleaving unit 70, a processing unit 72, and a deinterleaving unit 74.

  In the fourth mode, the absolute value comparison unit 88 acquires the log-likelihood ratio at the time of first reception stored in the fourth memory 86 and also acquires the log-likelihood ratio at the time of re-transmission / reception stored in the second memory 82. . The absolute value comparison unit 88 compares the absolute value of the log likelihood ratio {Λ (dk)} at the time of initial reception with the absolute value of the log likelihood ratio {Λr (dk)} at the time of retransmission, for each bit. Select the one with the larger absolute value. The absolute value comparison unit 88 performs bit-by-bit processing on the sequence corresponding to the information data at the first reception stored in the first memory 80 and the sequence corresponding to the information data at the time of retransmission stored in the third memory 84. Based on the selection result, any one is selected for each bit, and they are combined to generate a sequence {R ″ (dk)} corresponding to new information data.

  In the case of the fourth mode, the first decoding unit 62 generates a new sequence {R ″ (dk)}, a sequence {R (p1k)} corresponding to the first parity, and a sequence {R ( p2n)} is set to “0” as the prior value {La1 (dk)}, and then the decoding process is executed. The first decoding unit 62 outputs the posterior value {Le1 (dk)} as the decoding result to the interleaving unit 70. Interleaving unit 70 performs an interleaving process on posterior value {Le1 (dk)} to generate a priori value {La2 (dn)} and outputs a priori value {La2 (dn)} to processing unit 72. To do. The interleaving unit 70 also generates {R ″ (dn)} by performing an interleaving process for the new sequence {R ″ (dk)}.

  The processing unit 72 inputs the prior value {La2 (dn)}, the sequence {R ″ (dn)}, and the sequence {R (p2n)} and executes a decoding process. The processing unit 72 outputs the posterior value {Le2 (dn)} that is the decoding result to the deinterleaving unit 74. The deinterleaving unit 74 generates a prior value {La1 (dk)} by performing a deinterleaving process on the posterior value {Le2 (dn)}. The deinterleaving unit 74 outputs the prior value {La1 (dk)} to the first decoding unit 62. After this series of operations is performed once and decoding is repeatedly performed up to a specified number of times, the deinterleaving unit 74 rearranges the log likelihood ratio {Λ (dn)} acquired by the processing unit 72 to obtain the log likelihood ratio { Λ (dk)} is output to the second memory 82. In the case of the fourth mode, the selection unit 66 selects the second memory 82 and outputs the selected log likelihood ratio {Λ (dk)} to the hard decision unit 68. The hard decision unit 68 To generate decoded data.

  FIG. 13 is a flowchart showing an encoding procedure in the encoding unit 12. If the control unit 20 has not selected the first mode (N in S140) and has not been retransmitted (N in S142), the first encoding unit 50 executes the encoding process (S144). On the other hand, when the control unit 20 selects the first mode (Y in S140), the first encoding unit 50 executes the encoding process (S144). When the control unit 20 has selected the first mode (Y in S146), the second encoding unit 54 executes an encoding process (S148). The generation unit 56 selects puncture processing for the first mode (S150). When the control unit 20 does not select the first mode (N in S146), the generation unit 56 selects the puncture process for the second mode (S152). Here, it is assumed that the puncturing process is not executed in the second mode. If it is retransmission (Y of S142), the 2nd coding part 54 will perform coding processing (S154). The generation unit 56 selects the puncture process for the third mode (S156). Here, it is assumed that the puncturing process is not executed in the third mode. The generation unit 56 performs puncture processing (S158).

  FIG. 14 is a flowchart showing a decoding procedure in the decoding unit 36. If it is the first mode (Y of S170), the depuncture unit 60 selects the depuncture process for the first mode (S172). On the other hand, if not in the first mode (N in S170) and not retransmitted (N in S174), the depuncture unit 60 selects the depuncture process for the second mode (S176). Here, it is assumed that the depuncture process is not executed in the second mode. If it is retransmission (Y of S174), the depuncture unit 60 selects the depuncture process for the third mode (S178). Here, it is assumed that the depuncture process is not executed in the third mode. The depuncture unit 60 performs a depuncture process (S180).

  Initialization processing for decoding processing is executed (S182). If it is the first mode (Y of S184), or not the first mode (N of S184), or if it is not a retransmission (N of S186), the first decoding unit 62 executes the decoding process (S188). In the case of retransmission (Y in S190) or not in retransmission (N in S190), in the first mode (Y in S192), the interleaving unit 70 executes an interleaving process (S194). The processing unit 72 executes a decoding process (S196). If the number of repetitions has not reached the specified number (N in S198), the deinterleaving unit 74 performs a deinterleaving process on the posterior value (S200), and returns to Step 188.

  If the number of iterations reaches the specified number (Y in S198), the deinterleaving unit 74 performs deinterleaving processing on the log likelihood ratio (S208), and the hard decision unit 68 executes hard decision. (S210). When it is not the first mode (N in S192), the hard decision unit 68 performs a hard decision (S210). In the case of retransmission (Y in S186), if the CRC is NG (Y in S202), the absolute value comparison unit 88 compares the absolute values of the log likelihood ratios (S204), and executes the processing after step 188. To do. If CRC is not NG (N of S202), the 2nd decoding part 64 will perform a decoding process (S206). The deinterleaving unit 74 performs deinterleaving processing on the log likelihood ratio (S208), and the hard decision unit 68 performs hard decision (S210).

  According to the embodiment of the present invention, when retransmission occurs in the second mode, the second parity that has not been transmitted in the second mode is targeted for retransmission, and single decoding based on the retransmission in the third mode. By performing the above first, the following effects can be obtained. When an error occurs in the decoding result of the reception in the second mode due to sudden disturbance of the communication path, the situation of the communication path may be recovered at the time of retransmission. In such a case, if the independent decoding in the third mode is successful, an increase in the processing amount can be prevented.

  In addition, when the reception data in the third mode is incorrect, new reception data is obtained according to the log likelihood ratio based on the reception data in the second mode and the reception data in the third mode. Therefore, it is possible to generate highly reliable received data. In addition, since the decoding process is performed on the highly reliable received data, it is possible to suppress the deterioration of the reception characteristics. Further, since new reception data is generated based on the reception data that has already been received, transmission of new data can be omitted. In addition, since transmission of new data is omitted, deterioration of transmission efficiency can be suppressed. Since the reception sequence corresponding to the information data is selected based on the magnitude of the absolute value of the log-likelihood ratio at the first time and at the time of retransmission, it is higher compared to the case of simply judging from the information obtained from the likelihood of the demodulated data Accuracy can be obtained.

  As described above, since the reception value and the decoding result of each time can be handled independently, the operation is performed while reducing the power consumption by the second mode, and when an error occurs, retransmission or “initial reception result” is performed as necessary. And decoding result ”and“ retransmission / reception result and decoding result ”are combined with a new received value of information data to perform decoding with increased redundancy and correction capability.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the present embodiment, the encoding unit 12 performs the encoding process using the first mode or the second mode according to the estimation result of the communication path. However, the present invention is not limited to this. For example, the encoding unit 12 may use the second mode at the time of initial transmission and use the third mode at the time of retransmission. According to the present modification, the mode selection process according to the communication path estimation result can be omitted, so that the process can be simplified.

  In the present embodiment, the transmission apparatus 100 and the reception apparatus 200 select a mode according to a predetermined rule. However, the present invention is not limited to this. For example, the receiving apparatus 200 may request a mode when transmitting a NACK as a reception result. Further, the receiving apparatus 200 derives an average value of the absolute values of the log likelihood ratio obtained at the time of the first reception, and when the value falls below a preset threshold value, the third mode at the time of NACK return The use of the first mode may be requested instead of the use of. According to the present embodiment, retransmission according to the reception characteristic at that time can be realized.

  Further, each decoding when performing turbo decoding on a new information data reception sequence by storing for each bit whether the information data reception sequence at the initial time or at the time of retransmission is selected when shifting to the turbo operation at the time of retransmission. The time γ calculation may be simplified. For example, at the time of decoding by the first decoding unit 62, only γ corresponding to the bit replaced with the information data reception sequence at the time of retransmission may be recalculated with respect to the original initial information data reception sequence. Also, when performing turbo decoding based on the retransmission result, normally, all 0s are set as a prior value at the first decoding, but the second decoding is performed on the bits for which the information data reception sequence at the time of retransmission is selected. Decoding may be started using a value converted from the posterior value obtained by the unit 64 as an a priori value. Alternatively, instead of fixing the start of turbo decoding from the first decoding unit 62, starting decoding from the decoder associated with the larger number of selected bits of the information data series, the other decoding with low reliability is performed. Alternatively, it may be started by giving a prior value with some reliability instead of the prior value 0. Also in this case, if the average value of the absolute values of the log likelihood ratio can be obtained, it is possible to select whether to start the prior value with 0 or the other value depending on the size of the average value. Good.

  In the embodiment of the present invention, since the communication system is based on a wireless communication system, the transmission device 100 and the reception device 200 are included in the wireless communication device. However, the present invention is not limited to this. For example, the communication system may be based on a wired communication system. At that time, the transmission device 100 and the reception device 200 are included in a wired communication device. According to this modification, the present invention can be applied to various devices.

  10 information data generation unit, 12 encoding unit, 14 block interleaving unit, 16 modulation unit, 18 RF / amplification unit, 20 control unit, 30 amplification / RF unit, 32 demodulation unit, 34 block deinterleaving unit, 36 decoding unit, 38 data processing unit, 40 channel estimation unit, 42 control unit, 50 first encoding unit, 52 interleaving unit, 54 second encoding unit, 56 generation unit, 60 depuncture unit, 62 first decoding unit, 64 second Decoding unit, 66 selection unit, 68 hard decision unit, 70 interleaving unit, 72 processing unit, 74 deinterleaving unit, 80 first memory, 82 second memory, 84 third memory, 86 fourth memory, 88 absolute value comparison unit , 100 transmitting device, 200 receiving device.

Claims (7)

An input unit for inputting information data to be transmitted;
A first encoding unit that generates a first parity by performing an encoding process on the information data input in the input unit;
A second encoding unit that generates a second parity by sequentially performing an interleaving process and an encoding process on the information data input in the input unit;
As the operations of the first encoding unit and the second encoding unit, a control unit that defines at least a first mode and a second mode and selects one of the modes,
When the control unit selects the first mode, the information data input in the input unit, the first parity generated in the first encoding unit, and the second parity generated in the second encoding unit Based on the information data input in the input unit and the first parity generated in the first encoding unit when the transmission unit generates transmission data and the control unit selects the second mode, A generation unit for generating transmission data,
The control unit operates the first encoding unit and the second encoding unit in the first mode, and operates the first encoding unit in the second mode to operate the second encoding unit. A transmission apparatus characterized by stopping an encoding unit. The control unit further defines the third mode, and selects the third mode when retransmitting the transmission data generated by the generation unit in the second mode,
When the control unit selects the third mode, the generation unit transmits retransmission data based on the information data input in the input unit and the second parity generated in the second encoding unit. Produces
The transmission apparatus according to claim 1, wherein the first encoding unit stops when the control unit selects a third mode. In the first mode, information data, a first parity generated by encoding the information data, and a second parity generated by encoding the information data after interleaving A receiving unit that receives the received data including the information data and the first parity in the second mode;
A first decoding unit that generates first decoded data by performing a decoding process on the received data received by the receiving unit;
A second decoding data is generated by sequentially executing an interleaving process, a decoding process, and a deinterleaving process on the information data of the received data and the first decoded data generated in the first decoding unit. A decryption unit;
When the received data received by the receiving unit corresponds to the first mode, the second decoded data generated by the second decoding unit is output as information data, and the received data received by the receiving unit is the first data A selection unit for stopping the second decoding unit and outputting the first decoded data generated in the first decoding unit as information data when the second mode is supported;
A receiving apparatus comprising: When the reception data in the second mode is incorrect, the receiving unit sets the information data and the second parity generated by performing an interleaving process on the information data and then performing an encoding process as the third mode. Received data containing
The second decoding unit sequentially performs an interleaving process, a decoding process, and a deinterleaving process on the reception data generated by the receiving unit when the received data received by the receiving unit corresponds to the third mode. To generate second decoded data,
The selection unit stops the first decoding unit and receives the second decoded data generated by the second decoding unit when the received data received by the receiving unit corresponds to the third mode. The receiving apparatus according to claim 3, wherein the receiving apparatus outputs the data. And a generator that generates new reception data based on the reception data in the second mode and the reception data in the third mode when the reception data in the third mode is incorrect. ,
The first decoding unit generates first decoded data by executing a decoding process on the new received data generated in the generating unit when the received data in the third mode is incorrect. And
The second decoding unit sequentially performs an interleaving process, a decoding process, and a deinterleaving process on the first decoded data generated by the first decoding unit when the received data in the third mode is incorrect. To generate second decoded data,
The said selection part outputs the 2nd decoding data produced | generated in the said 2nd decoding part as information data, when the receiving data in the case of a 3rd mode are incorrect. Receiver device. Inputting information data to be transmitted;
Generating a first parity by performing an encoding process on the input information data;
Generating second parity by sequentially performing interleaving and encoding on the input information data;
The step of generating the first parity and the step of generating the second parity define at least a first mode and a second mode and select one of the modes,
When the selecting step selects the first mode, the transmission data is generated based on the input information data, the generated first parity, and the generated second parity, and the selecting step includes the second mode. A step of generating transmission data based on the input information data and the generated first parity when the mode is selected,
The step of selecting operates the step of generating the first parity and the step of generating the second parity in the first mode, and the step of generating the first parity in the second mode. A transmission method characterized by stopping the step of generating the second parity by operating the step of generating. In the first mode, information data, a first parity generated by encoding the information data, and a second parity generated by encoding the information data after interleaving Receiving the received data including the information data and the first parity included in the second mode; and
Generating a first decoded data by executing a decoding process on the received data;
Generating second decoded data by sequentially executing interleaving processing, decoding processing, and deinterleaving processing on the information data of the received data and the generated first decoded data;
When the received data that is received corresponds to the first mode, the generated second decoded data is output as information data, and when the received data that is received corresponds to the second mode, the second mode Stopping the step of generating decoded data and outputting the generated first decoded data as information data;
A receiving method comprising:

Images