Improved receivers for digital high frequency waveforms using turbo equalization

We develop a turbo equalization-based receiver for serial-tone HF waveforms, where the conventional decision feedback equalizer is replaced by a soft-in soft-out (SISO) equalizer, and the receiver iterates soft information between the equalizer and the decoder. To keep the computational burden of the iterative equalization and decoding procedure as low as possible, the SISO equalizer uses a linear filter, performing soft intersymbol interference cancellation. Simulation results show that the proposed receiver performs more than 2 dB signal-to-noise ratio better than a conventional DFE-based receiver over an ITU-R poor channel.