Abstract:

Tropospheric scatter communication,as an over-the-horizon communication method,is one of the main communication means in the future battlefield because of its high secrecy and interference resistance.Single carrier frequency domain equalization technology can effectively solve the problem of amplifier transmit peak power limitation and signal multipath fading,and is widely used in tropospheric scatter communication.However,in the SC-FDE systems,the residual inter-symbol interference after the frequency domain equalization can seriously affect the bit error rate (BER) performance of the scatter communication systems.To solve this problem,this paper proposes an MMSE-HDFE-RISIC equalization algorithm based on the minimum mean square error criterion for the SC-FDE scatter communication systems.The algorithm is based on the hybrid decision feedback equalization algorithm,which further reduces the impact of residual inter-symbol interference on the system performance by estimating the residual inter-symbol interference in the frequency domain and then summing up the compensation in the time domain.Simulation analysis shows that the proposed algorithm has a good BER performance under the scattering channel.Under QPSK modulation,the performance improvement is 2.9 dB compared to the MMSE frequency domain equalization algorithm and about 1 dB compared to the traditional hybrid decision feedback equalization algorithm.Under 16QAM modulation,the performance improvement is 1.3 dB compared to the MMSE frequency domain equalization algorithm and about 0.6 dB compared to the traditional hybrid decision feedback equalization algorithm.

Key words: scatter communication, SC-FDE, MMSE- HDFE-RISIC equalization