Patent ID: 7062700
Filing Date: 2006-06-13
Classification: H03M,H04L

Abstract:
1. A TTCM (Turbo Trellis Coded Modulation) encoder that encodes a plurality of input bits according to a rate control sequence, the encoder comprising: a top interleaver operably coupled selectively to interleave at least some input bits of the plurality of input bits; a top rate 2/4 constituent trellis encoder, communicatively coupled to the top interleaver and operable to receive selectively interleaved bits there from, that is operable to encode the selectively interleaved bits that have been interleaved by the top interleaver; a bottom interleaver operably coupled selectively to interleave at least some input bits of the plurality of input bits; a bottom rate 2/4 constituent trellis encoder, communicatively coupled to the bottom interleaver and operable to receive selectively interleaved bits there from, that is operable to encode the selectively interleaved bits that have been interleaved by the bottom interleaver; a MUX (Multiplexor) that alternatively selects encoded bits that are output from the top rate 2/4 constituent trellis encoder and the bottom rate 2/4 constituent trellis encoder to produce a first plurality of multiplexed bits and a second plurality of multiplexed bits; a puncturing functional block that is operable selectively to puncture the first plurality of multiplexed bits output from the MUX according to a first RC (Rate Control) of the rate control sequence to produce a first encoded symbol; wherein the puncturing functional block is operable selectively to puncture the second plurality of multiplexed bits output from the MUX according to a second RC of the rate control sequence to produce a second encoded symbol; a symbol mapper that maps the first encoded symbol according to the first RC thereby generating a first mapped symbol; wherein the symbol mapper maps the second encoded symbol according to the second RC thereby generating a second mapped symbol; wherein the first RC of the rate control sequence corresponds to a first modulation that includes a first mapping of either a first 16 QAM (Quadrature Amplitude Modulation) constellation or a first 16 APSK (16 Asymmetric Phase Shift Keying) constellation; wherein the second RC of the rate control sequence corresponds to a second modulation that includes a second mapping of either a second 16 QAM constellation or a second 16 APSK constellation; wherein the first mapped symbol and the second mapped symbol form an encoded signal; and wherein the encoded signal has a bandwidth efficiency that is greater than approximately 3 bit/s/Hz (bits per second per Hertz).