Blind space-frequency channel estimator for MC-CDMA systems with antenna arrays in frequency-selective fading environment

The multicarrier code division multiple access (MC-CDMA) technique is known to be appropriate for high-data-rate wireless communications due to its robustness to multipath fading and its capability of handling high-data-rate transmissions with a simple one-tap equalizer. This paper investigates a uniform linear antenna array at the base station for macrocell MC-CDMA systems in a frequency-selective fading channel environment, and develops a blind space-frequency channel estimator for an MC-CDMA system with antenna array. As a by-product, the direction-of-arrivals (DOAs) can also be estimated. By constructing a specific auxiliary matrix including both the space-frequency channel and DOA information, and performing eigen decomposition on it, we can obtain the closed-form solution of space-frequency channels and DOAs for all active users within the macrocell. The overall performance of this novel scheme is demonstrated by extensive computer simulations.