MMSE Receiver for DS-SS Systems in AWGN Channel

This implementation presents an adaptive receiver designed for Direct Sequence Spread Spectrum (DS-SS) systems operating in AWGN channels. The adaptive receiver module is modified from the LMS adaptive filter block in the DSP Blockset, implementing MMSE criteria through adaptive filtering techniques. For DS-SS signal reception, the adaptive filter requires multi-rate operation where the input sampling rate equals the chip rate and the output sampling rate equals the symbol rate. These two rates are related through the processing gain (PG) parameter, which determines the spreading factor. The implementation handles rate conversion through proper decimation and interpolation techniques, ensuring optimal symbol detection while mitigating noise effects through the MMSE criterion.