Research And Implements Of New Cascade Code In Satellite Communication

Satellite communication refers to the use of man-made earth satellite as a relay station, it transmits the information by transmitting or reflecting the electromagnetic waves in space. Satellite channel is a typical time-varying and fading channel. For the purpose of compensating the information quality in the receiver, the method of error-coding is more significant than increasing system power. The serial concatenated code which is made up of the outer code Reed-Solomon code and inner code TTCM code with inter-leaver between them has an large error-correcting capability that performs well against both random and burst errors. Nowadays, it has been widely used in many fields such as satellite communication, mobile communication systems.Reed-Solomon code is a class of error-correcting codes enjoyed countless applications. As a multi-band code, RS code has a strong ability to resist burst errors, so RS code is often used as a preferred error correcting code or as a component code in the design of a scheme for data transmission or storage error correction.Turbo code is one of the best encoding styles found so far. Its feedback iterative decoding is to a turbo. The decoding algorithm adopts SISO BCJR iterative algorithm. TCM combines coding and modulation, using the theory named "Subset Partition" rather than gaining the coding gain at the cost of expanding the band. In this thesis, TTCM combines the two codes and implements by using TCM as the component code in Turbo.Cascade code described in this thesis is the use of TTCM as the inner code and RS is the outer code and cascaded by the block inter-leaver. This is mainly to take advantage of the TTCM can be decoded by optimum Viterbi, besides RS has a burst error correction capability, thus the ability of correcting code error is greatly improved.Based on the theory of RS, TTCM and the characteristics of the satellite channel, a new cascade code in satellite communication was put forward in this thesis. First of all, it is simulated by MATLAB to judge its feasibility, and then C Language is used to implement the encoder and decoder of RS and TTCM, two kinds of code were cascaded by inter-leaver. At last, a set of data is transmitted to validate its feasibility.