| The traditional Last Mile solutions of home network are independent with eachother, which are conducted by different telecommunication standards. ITU-T proposed arecommendation on developing one united home network transceiver. In order toaccommodate the transmission medium including power lines, phone lines and coaxialcables, the standard defines the same MAC but different PHY. With widespread indoornetwork interface, the power line is chose as channel model in this paper. While thetransmission environment of power lines is interfered by severe frequency degradationand noise. As a result, research on the achieving robust high speed communication bypower lines becomes one hot issue all over the world.After studied the interference characteristics on the power line channel, we defineda channel model which is perfectly similar to real power line. Then we analyzed the fastLDPC (Low Density Parity Check) encoding algorithms with simulations. And wefound the simulation of the Efficient algorithm needs shortest encoding time andminimum memory space. On the other hand, we improved the LDPC decodingalgorithm after the comparative studies on Believe Propagation algorithm and Min-sumalgorithm. The simulation of the improved decoding algorithm suggested it has a goodperformance both on decoding complexity and low bit error rate. The followed chapterstudied mainly on the key technologies of the OFDM (Orthogonal Frequency DivisionMultiplexing), which included both synchronization technology and channel estimationtechnology. With the adoption of the improved T.Schmidl&D.Cox algorithm, moreprecise frame synchronization and minimum frequency offset are achieved. At the sametime, the channel frequency response estimation based on the direct judging algorithmhas a good performance.Finally, Physical Layer system simulation was conducted with differentcombinations of SNR and modulation mode.200M data transimitting velocity wasachieved under100M bandwidth with SNR15dB and16QAM modulation mode. |
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