Mimo Antenna Selection

Multiple input multiple output (MIMO) technique as a great breakthrough in wireless communication system can obtain high spectral efficiencies and MIMO-related topics are also hot spots of academic communications research nowadays. However, employing multiple antennas implies that the cost of additional hardware required will increase in the form of radio frequency (RF) chains. To solve these problems, while utilizing the advantages of multiple antennas, the technique of antenna selection was developed. The idea behind antenna selection is to use only a subset of transmit and/or receive antennas with better performance in MIMO systems.This paper proposes a rate control antenna selection based on approximate average signal to noise ratio (SNR). The approximate average SNR of receiving signal determines which transmitting antennas would be selected. The proposed system keeps average BER under the BER target, and spectral efficiency is maximized.For MIMO systems that need to keep transmission rate fixed, this paper proposes a reduced antenna selection criterion based on QR decomposition. The proposed system adjusts constellation and number of transmitting antennas to improve system's vector symbol error rate (VSER) performance in both flat fading and correlated fading channel, while keeping transmission rate fixed.In reduced antenna selection criterion based on QR decomposition, determination of diagonal elements of upper triangular matrix R. There are three different methods to determine diagonal elements of R: QR decomposition, Cholesky decomposition and LDL decomposition. This paper compares complexity and fixed point error of the three methods. This paper compares antenna selection system's fixed point VSER using three different methods.