I am trying to figure out if channel estimation and coherent demodulation is used in 802.11b receiver. I understand that 802.11b uses CCK coding with DBPSK or DQPSK for 5.5 and 11Mbps rates. But I am not able to figure out if Channel estimation and coherent demodulation is done at the receiver, and if it is done then how is it implemented.
But I am still confused if coherent detection/demodulation is done at the receiver in 802.11b. Since 802.11b uses Differential QPSK and BPSK which does not require coherent detection (Maybe I am wrong about this). A lot of texts say that 802.11b uses coherent detection. I just want to know the reason for using coherent detection in 802.11b.