The Study of Beamforming Techniques and Smart Antenna in Wireless MIMO-OFDM Systems
|關鍵字:||成波束天線;智慧型天線;正交多工;多輸入多輸出;Digital beamforming;Smart antenna;MIMO-OFDM system;MIMO Detection|
|摘要:||為了能夠有效的利用頻寬，使用智慧型天線(smart antenna)與數位訊號成波束技術(digital beamforming)可以提升多輸入多輸出 (MIMO) 的傳輸系統效能，其目地為提高訊號品質與消除其他訊號之干擾。
Smart antenna and digital beamforming in MIMO-OFDM system are an efficient way to improve the performance. Two of them are cancelling the interference signal and emphasize the interested signal. They can be used the antenna array to received signals and control the direction of the maximum gain via different phase adjustment. In this paper, we proposed a method to estimate the arrival of angle in smart antenna system. The method detects correlation of transmitted signal by search the maximal quality form transmitted-end. Moreover, according to this method, we can find an arrival angle on received-end and adjust the antenna angle to steering them. It can improve the interested signal quality. In digital beamforming system, if the signal arrival on received-end is skew, it will cause the signal performance terribly. We proposed a method to detect the channel environment to adjust the signal on received end. The received signal is computed a weighting vector to improve the SINR (Signal Interference Noise Ratio), increase capacity and enhance the signal quality. Through simulation in IEEE 802.11n platform with TGn channel D, It will show that the proposed algorithm with smart antenna performs a little degradation than with the prefect smart antenna system. And in digital beamforming system, using this detector to detect the channel impulse response and via phase adjustment will improve some performance then channel arrival skew. All of these simulations are in MIMO-OFDM 4×4 platform.
|Appears in Collections:||Thesis|
Files in This Item: