Abstract:

The effect of channel estimation error on the performance of multiuser multiinput multi-output (MIMO) systems with zeroforcing beamforming (ZFBF) in uncorrelated Rayleigh flat fading channels is investigated. An adaptive resource allocation algorithm with the total transmit power constrained and to satisfy the target bit error rate (BER) is proposed to maximize the system effective throughput. The active users are determined by users' channel state information and fairness. To obtain closed form solution for power and rate allocation, the algorithm uses the asymptotic Gaussian convergence characteristics of the packet outage probability. Numerical analysis shows that the system effective throughput is improved, benefited from the consideration of channel estimation error and the guarantee of users' quality of service (QoS) and fairness, while the computational complexity appears low.

Key words: zeroforcing beamforming, multiinput multioutput, effective throughput, adaptive resource allocation