Methods of MIMO decoders for very high throughput WLAN IEEE802.11ac

Exponential growing of wireless multimedia communications has forced the IEEE802.11 workgroup to define new standard of WLAN. It is named a Very High Throughput WLAN IEEE 802.11ac which exploits MIMO-OFDM technology to provide up to 6,9Gbps of throughput. MIMO decoder is the vital part of WLAN 802.11ac. It decodes the received signals to get back the transmitted information. There are many methods can be implemented in MIMO Decoder. The linear methods, such as Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) are simple but low in performance. At the other side, the well-known non-linear method called Maximum Likelihood Detection (MLD) measures the likelihood of the received signal to all symbol candidates. It gives an optimum performance by the cost of very high complexity. Between them, there are some sub-optimal methods, such as K-best, Trellis, and Sphere Detection. These three methods are low in complexity but give performance close to optimum. This paper is adressed to compare the performance and complexity of above methods as MIMO decoders for 8×8 WLAN 802.11ac. Observation is conducted under small room channel model.