Channel Coding And Cooperative Relaying Technologies For Power Line Communication

Power line communication is a communication technology which transmits data and exchanges information using existing power grid.Compared with the wireless communication network and traditional Ethernet,power line communication has many advantages such as no need for any infrastructure deployment,wide distribution and so on.Therefore,power line communication has become the most promising technology for last-mile broadband access,smart grid,intelligent building and home automation.On the other hand,when the high frequency signal is transmitted over the power line channel,the signal undergoes time variant,multipath fading,attenuation,interference etc.,so that the power line communication channel makes communication environment extremely harsh.Therefore,how to achieve high-speed and reliable data transmission via power line channel has become an important and applicable subject.This dissertation targets the problems of channel attenuation,impulsive interference and time variance,studies channel coding and cooperative relay technologies aiming to increase the system capacity and reduce the bit error rate and implemental complexity.The main contributions of this dissertation are listed as follows:1.We propose a polar coding scheme for the power line communication system to cope with the impulsive noise and thereby promote the system transmission performance.What's more,a matrix interleave operator is integrated to mitigate the error propagation caused by sudden strong impulsive noises and further enhance the decoding performance.The error-correction coding/decoding algorithm and system scheme are provided,finally the simulation results demonstrate that compared with LDPC and LT coding schemes,the polar coding scheme can be of great importance to practical power line communication systems.2.We propose a novel cascaded coding scheme which cascades the outer code LT code and the inner code polar code for the power line communication system to cope with the "error propagation" of polar code decoder in low SNR fields,thereby promote the transmission performance.The error-correction encoding/decoding algorithm and system scheme are provided,finally the simulation results demonstrate that compared with LDPC-LT cascaded coding schemes,the PC-LT cascaded coding scheme can be applicable to power line communication systems.3.We propose a novel broadband cooperative relaying system over power line communication using Fountain code and Forward(FCF).The upper bound of FCF system capacity is analyzed and the closed-form expression for FCF system capacity is derived.Numerical simulations reveal that in terms of the system capacity the performance in FCF mode outperforms direct transmission,AF and DF cooperative relaying transmission schemes.In addition,the effect of the electromagnetic compatibility regulations and relay locations is analyzed as well.4.We propose an adaptive three-phase differential transmission schemes for the two-way relay network to avoid channel estimation and perfect synchronization.The relay node generates the modulation transmission signal adaptively according to the relay node detection status in the first and second phases in order to obtain higher system performance.The simulation results demonstrate the effectiveness of proposed algorithm.Finally,to further decrease the implemental complexity,a sub-optimal combination algorithm is proposed and proved to be as effective as optimal combination algorithm.