QR based MIMO Receivers: A Survey of Complexity and Performance

Multiple Input Multiple Output (MIMO) becomes a key technology to achieve a higher data rates in wireless communication. The theoretical limit of MIMO capacity can be achieved by increasing the number of antennas at the transmitter and receiver. While increasing the number of antennas, receiver design becomes very much challenging. Maximum Likelihood Detector (MLD) provides a optimal performance only if the number of antennas and modulation order is small, Otherwise it is impossible to implement in real time. In this paper, we investigated mainly QRM-MLD, LRAD and SD based on Bit Error Rate (BER) and complexity to compare with MLD. Our comparison will be helpful in understanding the complexity –performance trade-off involved in various methods. And the diversity offered by various methods is discussed. This survey helps in choosing an appropriate method for the required channel conditions.