Patent ID: 8605831

Claim:
A method comprising: receiving a data symbol y over a communication channel, wherein the received data symbol y corresponds to a transmitted data symbol x; processing the data symbol y according to a model y=(h+Δh) x+z, where h is an estimate of the communication channel, Δh is a channel estimation error corresponding to the estimate h of the communication channel, and z is noise corresponding to the communication channel, and wherein processing the data symbol y comprises determining, with a hardware device, the estimate h of the communication channel, determining, with the hardware device, a mean square error σ h 2 corresponding to the channel estimation error Δh, and determining, with the hardware device, a likelihood value for a bit in the transmitted data symbol x at least in part by calculating a first quantity equal to σ z 2 +σ h 2 |x| 2 , where σ z 2 is the noise power of the communication channel, calculating a second quantity equal to e -  y - hx  2 σ z 2 + σ h 2 ⁢  x  2 , and calculating the likelihood value for the bit using at least (i) the first quantity and (ii) the second quantity.