Patent Number: 6,480,528

Title: Automatic gain control for improved decoding of multi-carrier signal

Abstract: A method and a receiver for processing a desired signal for decoding (i.e., by a decoder). In accordance with the method, an input signal that includes the desired signal and additional signals is received and filtered with a first filter having a bandwidth greater than a bandwidth of the desired signal. The filtered signal is then sampled to generate discrete time samples, which is then filtered with a discrete time matched filter. The filtered samples are then scaled with a scaling factor and quantized. A quantity related to an amplitude of the quantized samples (i.e., power) is measured, and the scaling factor is adjusted in accordance with the measured quantity. The quantized samples can be further processed (i.e., demodulated) and provided to a decoder. The desired signal can be a quadrature modulated signal, in which case matched filtering, scaling, and quantization are performed on the in-phase and quadrature components of the desired signal. The adjustment of the scaling factor can be performed by an automatic gain control (AGC) loop that compares the measured quantity (e.g., signal power of the quantized samples) against a predetermined value to generate error values. The AGC loop then filters the error values to generate the scaling factor. In an embodiment, the loop filtering can be performed with an integrator.

Inventors: Patel; Shimman (San Diego, CA), Wilborn; Thomas (San Diego, CA)

Assignee: Qualcomm Incorporated

International Classification: H04L 5/02 (20060101); H03G 3/30 (20060101); H04J 1/05 (20060101); H04L 5/06 (20060101); H04J 1/00 (20060101); H04B 001/707 ()

Expiration Date: 11/12/2019