I/Q imbalance compensation
US8503545B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 2007 |
| Grant date | Aug 6, 2013 |
| Priority date | — |
| Expiry date | Jan 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2647
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
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 (ρ) and phase imbalance factor (φ). 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 (ρ) and, the phase imbalance factor (φ) 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.