Phase and gain error control system for use in an I/Q direct conversion receiver
Patent 5249203 Issued on September 28, 1993. Estimated Expiration Date: 
February 25, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 25, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesGain tracker for digital modem Baseband carrier phase corrector Gain and phase correction in a dual branch receiver Direct conversion receiver with tri-phase architecture Digital demodulator for amplitude or angle modulation using truncated nonlinear power series approximations Patent #: 5121072 InventorAssigneeApplicationNo. 660492 filed on 02/25/1991US Classes:375/344, Automatic frequency control375/345, Automatic gain control455/324Homodyne (i.e., zero beat or synchrodyne reception)ExaminersPrimary: Kuntz, CurtisAssistant: Ghebretinsae, T. Attorney, Agent or FirmInternational ClassH04L 027/06AbstractA system for controlling for gain and phase errors due to mismatches between signal channels in direct conversion receiver having a pair of signal channels carrying I and Q baseband component signals which are in quadrature. In accordance with the system new I' and Q' signals are generated which may be viewed as analogs of the I and Q baseband components but which are related to twice the phase angle defined by the original I and Q baseboard components signal components. Phase angles are determined based on the original I and Q baseband components signals and the new I' and Q' signals. An error signal is then formed from these signals which can be analyzed to determine the gain and phase errors affecting the I and Q baseband components. These components can then be adjusted to correct for gain and phase errors in order to compensate for hardware mismatches between the signal channels in the receiver. | |
