Fast in-phase and quadrature imbalance calibration
US8654885B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2007 |
| Grant date | Feb 18, 2014 |
| Priority date | — |
| Expiry date | Apr 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3863
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An embodiment of the present invention includes a technique to calibrate receiver and transmitter in a communication system. N digitized samples I(n) and Q(n) are stored. The N digitized samples represent in-phase and quadrature (I-Q) components, respectively, of a down-converted signal from a receiver. The I-Q components are generated from a quadrature demodulator or modulator having I-Q imbalance. Phase and gain adjustment constants are computed from the N digitized samples to compensate for the I-Q imbalance using a closed form solution.Another embodiment of the present invention includes a technique to calibrate a transceiver in a communication system without using a calibrated reference receiver. A first test signal at a first frequency is injected to a transmitter having a quadrature modulator with I-Q imbalance. The quadrature modulator has a carrier frequency. The transmitter generates a transmitter signal. The transmitter signal is detected to generate a composite signal having the first test signal and a second test signal at a second frequency twice the first frequency. The composite signal is digitized. I-Q direct current (DC) offset, phase, and gain corrections are com…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.