Coexistence of cellular CDMA and FSM: interference suppression using filtered PN sequences

The spectrum sharing between a direct sequence code division multiple access personal communications network (DS CDMA PCN) and the fixed service microwave (FSM) radio links in the 1850 to 1990 MHz band is investigated. The spectrum coexistence of the two systems will improve spectral efficiency, but it will cause interference to both systems. To reduce the interference, the spread spectrum (SS) technique is used in the PCN. In addition a CDMA PCN transmitter is designed, employing filtered pseudonoise (PN) sequences, that reduce the interference to the FSM systems. The performance of the FSM under the overlaid filtered PCN is studied. Next, a CDMA PCN receiver is designed, employing filtered PN sequences, and the performance of the filtered PCN, under FSM interference, is evaluated in terms of the CDMA capacity reduction