Communication device, spread-spectrum receiver, and related method using normalized matched filter for improving signal-to-noise ratio in harsh environments

A method of operating a communication device, the method comprising:

• receiving, at a receiver, an incoming RF signal;
• demodulating, with a demodulator of the receiver, the incoming RF signal to generate a baseband signal;
• filtering the baseband signal with a normalized matched filter having filter characteristics matched to a pulse-shaping filter of a transmitter that generated the incoming RF signal, the filtering comprising:
• partitioning the baseband signal to obtain a number of sampled segments;
• performing an FFT on a sequence including a sampled segment of the number of sampled segments;
• normalizing the sequence in the frequency domain;
• applying a matched filtering operation to the normalized sequence to generate a matched filtered sequence;
• performing an inverse FFT on the matched filtered sequence to generate a result;
• and
• performing an overlap-add operation with the result in the time domain to generate a normalized output;
• and
• extracting a received signal from the normalized output generated by the normalized matched filter.