摘要：In order to reduce the influence of multipath propagation on signal transmission in the OFDM wireless network, a novel HARQ scheme based on frequency diversity and Energy-MRC is proposed. This scheme takes the times of accurate transmission of previous data as reference value of present data transmission. When the data is retransmitted, the position in which information sequence lives after constellation mapping is changed before IFFT. So each time subcarrier fading relativity of the same information sequence is small, and major frequency diversity gain is obtained. In the receiving terminal, energy of the same information sequence in many times of transmission is maximal ratio combined after FFT. Under Rayleigh fading channel environment, simulation experiment shows that this scheme can reduce effectively BER(Bit Error Rate), compared with HARQ scheme without frequency diversity and MRC based on channel impulse response power. This scheme is easy to realize, and complex channel estimation is avoided.
关键词：Frequency Diversity;Maximal Ratio Combining(MRC);Hybrid Automatic Repeat Request( HARQ);OFDM;Frequency Selective Fading
