Low Complexity PIC-MMSE Detector for LDS Systems over Frequency-Selective Channels

In this paper, we examine the bit error rate (BER) performance of low-density spreading (LDS) systems employing the minimum mean square error (MMSE) and parallel interference cancellation (MMSE-PIC) detector in frequency-selective fading channels while additionally proposing a precoding scheme for multipath channels which effectively transforms the multipath channel into a single path channel. Numerical studies illustrate that the precoding scheme is effective and that reliable communication is possible, even in harsh multipath conditions.