Equalizer training for high-speed indoor wireless transmission

A high-speed indoor QPSK radio system for transmissions of ATM cells has been investigated in relation to the required training time of a decision feedback equalizer (DFE). The system operates at a raw bit rate of 20 Mbps and the access point handles the medium access control by giving the (mobile) stations permission to transmit. The access point receiver can store equalizer tap settings during an initial transmission from a certain station. During a subsequent transmission from a (mobile) station the access point receiver can reload the previously stored equalizer tap settings since the access point knows which station has started a transmission. The training of the DFE equalizer has been optimized with regard to the initial/subsequent training time, mobility robustness and timing offset between successive transmissions