Title :
Multiple turbo codes
Author :
Divsalar, D. ; Pollara, F.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
We introduce multiple turbo codes and a suitable decoder structure derived from an approximation to the maximum a posteriori probability (MAP) decision rule, which is substantially different from the decoder for two-code-based encoders. We developed new rate 1/3 and 2/3 constituent codes to be used in the turbo encoder structure. These codes, for 2 to 32 states, are designed by using primitive polynomials. The resulting turbo codes have rates b/n, b=1, 2 and n=3, 4, and include random interleavers for better asymptotic performance. A rate 2/4 code with 16QAM modulation was used to realize a turbo trellis coded modulation (TTCM) scheme at 2 bit/sec/Hz throughput, whose performance is within 1 dB from the Shannon limit at a BER=10-5
Keywords :
approximation theory; decision theory; encoding; interleaved codes; maximum likelihood estimation; polynomials; quadrature amplitude modulation; trellis coded modulation; 16QAM modulation; BER; MAP decision rule; Shannon limit; TTCM; approximation; asymptotic performance; decoder structure; maximum a posteriori probability; multiple turbo codes; primitive polynomials; random interleavers; rate 2/4 code; throughput; turbo encoder structure; turbo trellis coded modulation; Bit error rate; Convolutional codes; Decoding; Error correction codes; IEEE news; Laboratories; Modulation coding; Propulsion; Throughput; Turbo codes;
Conference_Titel :
Military Communications Conference, 1995. MILCOM '95, Conference Record, IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-2489-7
DOI :
10.1109/MILCOM.1995.483313
