Residue-division multiplexing for discrete-time signals

Multiplexing is a technique for dividing a single transmission channel into a number of virtual subchannels. The present paper introduces a new multiplexing system for discrete-time signals based on a polynomial factorization. In this multiplexing system, a linear-filter additive-noise channel is decomposed into independent subchannels that are also modeled as linear-filter additive-noise channels. A configuration and an analysis of the multiplexing system as applied to mobile communications are described in detail, based on a specific selection of polynomial factorization. Multicarrier code-division multiple access (MC-CDMA) is receiving much attention in the field of mobile communications because of its time and frequency diversity property. As is the case with MC-CDMA, in the proposed multiplexing system, the subchannel information is dispersed uniformly in both frequency and time so that degradation localized in frequency or time average out over the subchannels. The averaging has the effect of decreasing the total error probability of transmission. Unlike MC-CDMA however, the multiplexing system creates multiple carriers simply by up-sampling a single complex sinusoidal carrier for each subchannel user. Because of the simple mechanism, the implementation cost is less than that of MC-CDMA.