The research on MMSE equalization algorithm for HFDL signal

HFDL working in the short wave band is interfered by the multipath effect, and Turbo equalizer could achieve excellent performance when dealing with the Inter symbol interference (ISI) which is caused by the multipath effect. According to the signal characteristics of HFDL, this article designs Turbo equalizer, which was based on MMSE equalization algorithm, and proposes the solutions to the problems we often encounter, including channel impulse response estimating, mutual mapping between symbol information and bit information, the Probe´s Soft information setting. Meanwhile, according to HFDL signal frame structure features, the article designs the low-complexity approximate minimum mean square error (LC app MMSE) algorithm based on the Probe´s cycle time. The algorithm overcomes the shortcomings of the traditional LC app MMSE when dealing with the varying channel, and has high practical application value. Finally, the simulation was completed for verifying the solution and the algorithm. The results show that the performance of Turbo equalizer is far superior to DFE.