Complex processing in quaternary direct-sequence spread-spectrum receivers

The processing that is often employed in receivers for quaternary direct-sequence spread-spectrum communications operates separately on the inphase and quadrature components of the spread-spectrum signal. Previous results on quaternary complex sequences, which are also referred to as four-phase sequences, provide a strong motivation to employ processing methods that permit the receiver to benefit from the correlation properties of the complex sequences. This can be accomplished through the use of complex processing in the receiver. Receiver architectures are developed to take advantage of the improved periodic correlation properties of the quaternary complex sequences, and an analysis is presented which relates the performance of these receiver architectures to the complex correlation functions for the spreading sequences