| 摘要 |
A ZIF direct-conversion OFDM receiver capable of estimating and correcting an I/Q imbalance in a baseband signal. A complex down-conversion is performed on a received signal r(t). The received signal r(t) is divided into an In-phase signal (I) and Quadrature-phase signal (Q). An I/Q imbalance is introduced by the local oscillator such that the I/Q imbalance includes an amplitude imbalance factor (rho) and phase imbalance factor (phi). The I and Q signals are amplified, filtered and digitized. The digitized I and Q signals are processed via a Fast Fourier Transform (FFT). An I/Q compensation algorithm estimates the values of the amplitude imbalance factor (rho) and, the phase imbalance factor (phi) based on a time expectation calculation. The imbalance factors are applied to the baseband signal to recover the signal of interest x(t). The OFDM receiver outputs the signal of interest x(t) to an information display device.
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