On the coexistence of N-CDMA and analog FM/FDMA cellular telephonesystems in adjacent spectrum

摘要

Coexisting analog frequency modulation (FM) based on frequencydivision multiple access (FDMA) and narrow-band code division multipleaccess (N-CDMA) in adjacent spectrum is studied. The allocation ondifferent spectrum can avoid the serious performance degradation astransitioning from fully loaded analog FM/FDMA to N-CDMA. The guard-bandneeded between the adjacent spectrum to maintain acceptable performancedegradation is derived and evaluated. Numerical results indicate that atleast a 255 kHz bandwidth to separate the two systems is necessary. Theworst case of the interference from FDMA degrades the performance ofN-CDMA, even under appropriate guard-band separation. This studydemonstrates the capacity reduction of N-CDMA as coexisting analogFM/FDMA in adjacent spectrum