Smart antenna concepts with interference cancellation for joint demodulation in the WCDMA UTRA uplink

Two different smart antenna joint demodulation schemes with iterative interference cancellation for uplink transmission in the Universal Mobile Telecommunications System (UMTS) terrestrial radio access (UTRA) with wideband code-division multiple access (WCDMA) are derived in the framework of the space-alternating generalized expectation-maximization (SAGE) algorithm using a common channel model. The both schemes rely either on directional information or the spatial diversity of the mobile radio channel. It is shown via simulations that for a large number of waves impinging at the receiver the latter scheme being less complex is more robust in terms of the achievable bit-error rates than the former one while the performance is similar in channels with a small angular spread