Interleaver design for the Circular Simplex Turbo Block Coded Modulator
The Circular Simplex Trellis Coded Modulation, CS-TBCM,is a patented innovative technique that is oriented to fit within military applications and the next generation of portable telephones. In these particular applications, excess bandwidth is available for coding, due to the use of spread spectrum; short delay is critical for an efficient transmission. The CS-TBCMuses non-binary, non-recursive-convolutional encoders and does not use zero padding as a state termination between blocks of information. This dissertation provides a heuristic interleaver design algorithm for non-binary and binary turbo-coded set-ups for which performance bounds and mathematical analyses are not available or are difficult to obtain. A comprehensive description of the encoding process in the CS-TBCMand a comparison with the binary counterpart is also provided. The goal was to find an interleaver design methodology capable of improving the interleavers that were in place, to do it for any size, to reduce the time to find these interleavers and to have a sound explanation of why the design improves upon the previous ones. This research provides the computer programs needed to design interleavers (N<1000 bits) with desired characteristics: spread, dispersion and correlation. These programs in conjunction with statistical estimation provide suitable interleavers for binary and non-binary turbo coded set-ups. Even though optimality cannot be guaranteed; the application of the algorithm on the CS- TBCMhas been proven successful, new benchmarks have been created and the basis for reaching optimality have been described.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:interleaver design circular simplex turbo block coded modulator
Date of Publication:01/01/2003