AN ADAPTIVE CANCELER OF COCHANNEL INTERFERENCE FOR SPREAD-SPECTRUM MULTIPLE-ACCESS COMMUNICATION-NETWORKS IN A POWER-LINE

This paper proposes and investigates an adaptive canceller of intersymbol and cochannel interference in a direct-sequence spread-spectrum multiple-access (DS-SSMA) system, which are due to channel distortion and cross-correlation among pseudonoise (PN) sequences assigned to individual users. In order to implement a local area network (LAN) by using a power line installed in a building wall as a transmission channel, we have investigated utilization of DS-SSMA which has advantages such as robustness against narrow-band interference and noise and realization of asynchronous code division multiple access. In a power line, however, restriction of transmission bandwidth for communications makes it difficult to suppress cochannel interference and the channel is also time-varying due to fluctuation of loads. Since the proposed canceller adaptively eliminates cochannel interference as well as intersymbol interference, it can facilitate synchronization and increase the number of the simultaneously accessing users in a power line with restricted processing gain. The error probability in the output of the canceller is theoretically calculated for the steady-state case by using a Markov model. Moreover, computer simulations illustrate stable convergence properties of the canceller. © 1990 IEEE