Patent ID: 7876856

Claim:
A low-IF quadrature receiver comprising: A. an antenna for receiving a radio frequency signal; B. a RF receiver having an input connected to the antenna and outputs carrying quadrature analog IF signals; C. an analog receiver having inputs connected to the outputs of the RF receiver and having outputs carrying quadrature digital IF band signals; D. digital filters having inputs connected to the outputs of the analog receiver and having outputs carrying in-phase and quadrature components of quadrature signals; E. a correction engine having inputs connected to the outputs of the digital filters, a complex-valued filter coefficient w input, and a v output; F. a coefficient controller having a complex-valued filter coefficient w output connected with the complex-valued filter coefficient w input, a complex-valued filter coefficient wA input, and a third coefficient output; G. an adaptation engine having inputs connected with the outputs of the digital filters, a complex-valued filter coefficient wA output connected with the complex-valued filter coefficient wA input, and a third coefficient input connected with the third coefficient output, the adaptation engine including a vA output; and H. a multiplexer having one input connected with the v output, another input connected with the vA output, and a v(n) output; and wherein the outputs of the digital filters include u outputs carrying in-phase u I and quadrature u Q components of the quadrature signals, the adaptation engine produces a complex-valued filter coefficient wA signal on the complex-valued filter coefficient wA output in response to a difference in signal power between the u I and u Q components of the quadrature signals.