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

Abstract

The standard time division multiple access (TDMA) cellular network is designed so that physically adjacent cells are assigned different frequency bands, or channels, in order to reduce inter-cell interference. A multiple-access scheme is presented in which TDMA is used inside each cell, but different transmitted pulse shapes with low cross-correlations are assigned to adjacent cells. These pulses could be direct-sequence spread-spectrum pulses, which have been proposed for code division multiple access (CDMA) wireless networks. Such a hybrid system combines the high intra-cell capacity of TDMA with the inter-cell and multipath interference rejection capabilities of CDMA. It is concluded 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 are discussed.