Patent ID: 8682251

Claim:
A method performed by a communication device for estimating a subchannel power imbalance ratio (SCPIR) between a pair of subchannels consisting of a first subchannel and a second subchannel, the method comprising: receiving at the communication device a modulated signal, the modulated signal comprising a first signal intended for the communication device and a second signal intended for another communication device, the first signal comprising a first training sequence (TS 1 ) and the second signal comprising a second training sequence (TS 2 ) that is paired with TS 1 ; producing from the received modulated signal a sample sequence (r); using TS 1 and r to estimate a channel impulse response of length K for the first subchannel, where h 1 denotes the estimated channel impulse response for the first subchannel and K is greater than or equal to 1; using TS 2 and r to estimate a channel impulse response of length K for the second subchannel, where h 2 denotes the estimated channel impulse response for the second subchannel; and estimating the SCPIR from h 1 and h 2 .