FREQUENCY-DEPENDENT IQ IMBALANCE ESTIMATION

摘要

RF impairment parameters, including frequency- dependent IQ imbalance, are estimated in a wideband received signal on a per- sub-band (or per sub-band pair) basis. In one embodiment, block- type pilot signals are received, such as on SCH, and IQ imbalance and carrier frequency offset are estimated from the block- type pilot signals. Data and comb- type pilot signals are then received on all sub-bands. Phase noise and channel coefficients are estimated for the first sub-band, based on the IQ imbalance and carrier frequency offset estimates. IQ imbalance is then successively estimated, on a per- sub- band (or per sub-band pair) basis, based on the comb- type pilot signals, the previously estimated carrier frequency offset estimate, and the phase noise and IQ imbalance estimates from prior sub-bands (or pairs). This may comprise iterative estimation based on decision feedback.