Research On Turbo Product Codes In Optical Communication

Forward error correction (FEC) codes are one of the key technologies in the optical communications with the increasing demand for higher capacity for dense wavelength division multiplexing (DWDM) systems. The well channel coding can efficiently improve the system performance. A new kind of FEC, called turbo product codes (TPCs), whose performances in terms of bit error rate (BER) are close to the Shannon limit, is introduced to modern communication. However, there are still many operations, i.e. implementation complexity degradation, required during TPC decoding. This thesis mainly focuses on the implementation complexity and the decoding latency, and proposes an efficient TPC decoding algorithm. At last, we discuss the affection of the efficient TPC decoding algorithm in the optical communication.Firstly, a few of fundamental theories of channel code are introduced; encoding and decoding principles of TPCs and main decoding algorithm are described, as well as the simulation results of TPC decoding algorithm, and the performance of TPCs, Turbo codes and convolution codes is compared.Secondly, an efficient althorithm is proposed witch can reduce the implementation complexity and decoding delay of the original TPCs. An efficient Chase decoder is proposed where the test patterns are ordered conventionally that can reduce the decoding complexity by an order of magnitude with no performance degradation. We also propose that the weight and reliability factors can be fixed, and that there is no need for normalization of the extrinsic information. To decrease decoding latency, a kind of parallel TPC algorithm is employed. The parallel decoding algorithm can half the decoding delay with only a little loss in performance.Finally, the performance of the efficient althorithm in the optical system is discussed. We research the system model of the long-haul single-mode fiber...