Asynchronous fast frequency-hopping CDMA cellular systems

We address the problem of constructing frequency-hopping codes for use in a fast frequency-hopping code-division multiple-access cellular system with a K-cell frequency-reuse scheme. Different hopping codes are used in different cochannel cells to reduce the cochannel interference. The frequency-hopping patterns possess ideal auto- and cross-correlation properties for use in the intracells and ideal autocorrelation and nearly ideal cross-correlation properties in the cochannel intercells. Additionally the cardinalities (the number of patterns) of the codes for use in the intracells meets the bound and hence are optimal. The maximum number of users which can be accommodated by using the proposed scheme is 20% more than the scheme using the same frequency-hopping code in all cells under a carrier-to-interference ratio of -15 dB.