الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The Long Term Evolution (LTE) mobile system suffers from performance degradation due to problems of interference and multipath fading. To solve this problem, robust Direction of Arrival (DOA) based blind beamforming is proposed in order to achieve the requirements of the LTE system. The proposed methods are applied to LTE system in the uplink direction at the base station (eNodeB) that is equipped with a uniform linear array for the purpose of efficient interference mitigation and multipath effect rejection for single and multiuser cases. First, a reduced complexity super resolution DOA algorithm is proposed in order to resolve the multipath components of a single user. Also the estimation of DOA of multiuser is implemented per a subchannel assigned to every user. The obtained DOA information in both cases is exploited for a robust beamforming, and the resolved paths in the single and multiuser cases can be exploited for improvement of an output signal to noise ratio (SNR). Moreover, in the case of interference from adjacent cells in the multipath environment, the DOA of interference is estimated first by a super resolution algorithm and is then exploited for DOA estimation of the desired user. Data are detected efficiently after rejecting the effect of multipath and interference using a robust blind beamforming. In addition, non-blind beamforming combined with channel estimation is proposed for the same purpose. By those proposed algorithms the results show that the data can be received with a low bit error rate (BER) level using different modulation schemes in the 4G LTE-uplink system.