Research on the broadband power line communication system based on adaptive OFDM

There are characteristics of high noise, big attenuation, the big impedance variation and the uneven frequency response on low-voltage power line channel. Firstly, this paper proposes the combination the adaptive technology with the OFDM technology to realize the reliable and high-speed data transmission channel. It is a key to study the channel estimation of the OFDM technology and the channel allocation of the adaptive technology. Then, we put forward to the algorithm of comb-type pilots Unscented Kalman Filter, and we use the time-frequency domain estimation algorithm to improve the channel estimation accuracy. Lastly, we take the improving particle swarm algorithm to solve the problem of the channel allocation and the bit allocation, realize the sub-carrier bits and the power allocation in multiuser adaptive OFDM system, save running time, reduce the transmitted power and enhancing the efficiency of spectrum.