Asynchronous SSMA system using secret polyphase orthogonal sequences with elimination filter for co-channel interference
N. Suehiro · 2003
A filter is discussed which has been proposed for eliminating cochannel interference without using the knowledge of the sequence of cochannel interference in an asynchronous spread-spectrum multiple-access (SSMA) system, in which each transmitter/receiver is assigned an infinite number of sequences and selects a sequence secretly for channel security. The filter gathers the cochannel interference energy into some pulses and scatters the signal energy widely. The receiver can clip the cochannel interference energy by losing a small amount of signal energy. This is a new solution for the near-far problem in an asynchronous SSMA system using secret sequences.>