Low complexity decision directed channel tracking for MIMO WLAN system

It is expected that the next generation wireless local area networks will be predominantly based on MIMO-OFDM physical layer. The performance of coherent MIMO-OFDM based systems critically depends on the availability of accurate channel estimations. Preambles, at the beginning of each packet, are used to estimate the channels in IEEE 802.11n systems. However, in mobile communication, when the channel is time varying, the channel variations within a given packet increases the packet error rate (PER) in the system. So the channel variations have to be tracked by the receiver. This paper proposes a low complexity channel tracking scheme for 802.11n systems to improve the PER. The delay introduced by the channel tracking scheme is within the acceptable limits.