Frequency-Domain Adaptive Antenna Array for Multi-Code MC-CDMA

MC-CDMA is an attractive multi-access method for the next generation high-speed mobile communication systems. The uplink transmission performance is limited by the multi-access interference (MAI) from other users since all users share the same bandwidth. Adaptive antenna array can be used to suppress the MAI and to improve the uplink transmission performance. In this paper, we propose a frequencydomain adaptive antenna array for multi-code MC-CDMA. The proposed frequency-domain adaptive antenna array uses a simple normalized LMS (NLMS) algorithm. Although the NLMS algorithm is used, very fast weight convergence within one MC-CDMA symbol duration is achieved since the weight updating is possible as many times as the number of subcarriers within one MC-CDMA symbol duration. key words: MC-CDMA, adaptive antenna array, adaptive algorithm, frequency-domain