Data transmission system, receiver, and recording medium

• US 6,269,124 B1
• Filed: 06/01/1998
• Issued: 07/31/2001
• Est. Priority Date: 06/26/1997
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Murakami, Keishi, Nagayasu, Takayuki
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): BAYARD, EMMANUEL
• Application Number:
  US09/087,926
• Time in Patent Office: 1,156 Days
• Field of Search: 375/265, 375/259, 375/262, 375/263, 375/341, 714/746, 714/701, 714/716, 714/750, 714/752, 714/754, 714/759, 714/761, 714/774, 714/786, 714/794, 714/797, 714/796, 714/795, 341/143
• US Class Current: 375/262
• CPC Class Codes: H03M 13/3776 using a re-encoding step during the decoding process
• CPC Class Codes: H03M 13/41 using the Viterbi algorithm or Viterbi processors
• CPC Class Codes: H03M 13/4146 soft-output Viterbi decoding according to Battail and Hagenauer in which the soft-output is determined using path metric differences along the maximum-likelihood path, i.e. "SOVA" decoding
• CPC Class Codes: H03M 13/45 Soft decoding, i.e. using symbol reliability information H03M13/41 takes precedence
• CPC Class Codes: H04L 1/0051 Stopping criteria
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 25/0202 Channel estimation

Abstract

A data transmission system, a receiver, and a recording medium in which a re-coder (16) generates pseudo transmission signals based on the virtual received data after a decoder (15) generates virtual received data based on virtual decision data from a virtual decision circuit (12), and a soft-decision circuit (18) outputs soft-decision data so as to decrease the number of different bits between the pseudo transmission signals and the received signals, and the received data are generated based on the soft-decision data.

Claims

1. A data transmission system comprising:

a transmitter for outputting transmission signals corresponding to transmission data after said transmission data are generated by coding processing with error correction;

a receiver for receiving said transmission signals and for generating received signals corresponding to said transmission signals, for extracting virtual received data from said received signals by decoding process (error-correction process), for generating pseudo transmission signals based on said virtual received data, and for correcting said virtual received data so that said pseudo transmission signals are approached gradually to said transmission signals transmitted from said transmitter, and for using said corrected virtual received data as said received data.

2. A receiver comprising:

a receiving section for receiving transmission signals corresponding to transmission data that have been processed by a coding processing for the purpose of error correction and transmitted from a transmitter, and for outputting received signals;

a virtual received data extraction section for decoding said received signals for the purpose of error correction, and for outputting virtual received data;

a pseudo signal generation section for performing calculation processes, that includes said same coding processing performed by said transmitter, for said virtual received data, and for generating pseudo transmission signals; and

a virtual received data correction section for correcting said virtual received data based on said pseudo transmission signals, said received signals, and a channel impulse response through which said transmission signals are transmitted, and for using said corrected virtual received data as said received data.

3. A receiver comprising:

a receiving section for receiving transmission signals corresponding to transmission data that have been processed by coding processing for the purpose of error correction and transmitted from a transmitter, and for outputting received signals;

virtual decision means for extracting virtual decision data from said received signals based on a channel impulse response through which said transmission signals are transmitted;

decoding means for performing decoding processing for the purpose of error correction for said virtual decision data and for generating and outputting virtual received data;

re-coding means for performing said coding processing for said virtual received data;

a soft-decision means for outputting soft-decision data based on pseudo transmission signals, said received signals, and said channel impulse response; and

switching means for providing said soft-decision data instead of said virtual decision data to said decoding means,

wherein said soft-decision data are inputted at least one time into said decoding means, and final virtual received data in said virtual received data outputted from said decoding means are outputted as said received data.

4. A receiver as claimed in claim 3, wherein said virtual decision means comprises a channel impulse response estimation circuit for estimating said channel impulse response based on said received signals, and a virtual decision circuit for extracting said virtual decision data from said received signals based on said estimated channel impulse response.

5. A receiver as claimed in claim 3, wherein said soft-decision means comprises a channel impulse response updating circuit for updating said channel impulse response based on said pseudo transmission signals, and said received signals, and a soft-decision circuit for generating and outputting soft-decision data based on said updated channel impulse response, said pseudo transmission signals, and said received signals.

6. A receiver as claimed in claim 3, wherein said decoding means comprising:

a deinterleave circuit for deinterleaving said virtual decision data; and

a decoding circuit for performing decoding processing for the purpose of error correction for said virtual decision data that have been deinterleaved, and

said re-coding means comprising;

a re-coding circuit for performing a same coding processing performed by said transmitter for said virtual received data outputted from said decoding means, and

an interleave circuit for performing same interleave processing performed by said transmitter for said re-coded virtual received data.

7. A receiver as claimed in claim 6, wherein said re-coding circuit performs convolutional coding, and said decoding circuit performs Viterbi decoding.

8. A receiver as claimed in claim 3, further comprising:

an error number detection circuit for comparing said decision data inputted to said decoding means with said re-coded data outputted from said re-coding means in order to count an error number as a number of different bits of said decision data and said re-coded data and for outputting said error number; and

a loop number control circuit for controlling whether correction processing for said virtual received data is continued or halted based on said error number outputted from said error number detection circuit.

9. A receiver as claimed in claim 6, further comprising:

an error number detection circuit for comparing said data inputted to said interleave circuit with said data outputted from said deinterleave circuit in order to count an error number as a number of different bits of them and for outputting said error number; and

a loop number control circuit for controlling whether correction processing for said virtual received data is continued or hated based on said error number outputted from said error number detection circuit.

10. A receiver as claimed in claim 3, wherein said receiving section comprising P (P≧

1) receiving parts for receiving transmission signals corresponding to transmission data that have been processed by coding processing for the purpose of error correction and transmitted from a transmitter, and for outputting P received signals, said virtual decision means extracts virtual decision data from said P received signals based on P channel impulse response through which said transmission signals are transmitted respectively, said decoding means performs decoding processing for the purpose of error correction for said virtual decision data and for generating and outputting virtual received data, said re-coding means performs said coding processing for said virtual received data, said soft-decision means outputs soft-decision data based on pseudo transmission signals, said P received signals, and said P channel impulse response, said switching means provides said soft-decision data instead of said virtual decision data to said decoding means, and wherein said soft-decision data are inputted at least one time into said decoding means, and final virtual received data in said virtual received data outputted from said decoding means are outputted as said received data.

11. A recording medium for storing a program that is readable by a computer, and said program performing functions comprising the steps of:

extracting virtual decision data based on received signals based on a channel impulse response through which said received signals are transmitted;

performing decoding processing for the purpose of error correction for said virtual decision data, and outputting virtual received data;

performing re-cording for said virtual received data;

performing a soft-decision for pseudo transmission signals, said received signals, and said channel impulse response, and outputting soft-decision data;

performing switching processing for inputting said soft-decision data instead of said virtual decision data into said decoding processing; and

performing a loop number control processing for inputting said soft-decision data at least one time and outputting final virtual received data in said virtual received data outputted from said decoding processing as said received data.