Hybrid intra-cell TDMA/Inter-cell CDMA with inter-cell interference suppression for wireless networks

Time-Division Multiple-Access (TDMA) and Code-Division Multiple-Access (CDMA) have received much attention as potentially attractive multiple-access techniques for wireless networks, such as the future Personal Communication Network. The standard TDMA cellular network is designed so that physically adjacent cells are assigned different frequency bands, or channels, in order to reduce inter-cell interference. Here we present a multiple-access scheme in which TDMA is used inside each cell, but different transmitted pulse shapes with low cross-correlations are assigned to adjacent cells. For example, these pulses could be Direct-Sequence Spread-Spectrum pulses, which have been proposed for CDMA wireless networks. Such a hybrid system combines the high intra-cell capacity of TDMA with intercell and multipath interference rejection capabilities of CDMA. We conclude that this hybrid scheme offers a potential increase in capacity relative to intra-cell TDMA/ inter-cell Frequency-Division Multiple Access(FDMA) provided that interference suppression techniques can be used to suppress inter-cell interference. Additional advantages and disadvantages of the scheme will be discussed.