Abstract: Techniques to adjust the setpoint of a power control loop in a wireless communication system. The setpoint may be adjusted based on frame status indicative of erased/good decoded frames, one or more (typically soft) metrics indicative of the confidence in the decoded results, power surplus/deficit indicative of the difference between the received signal quality and the setpoint, setpoint surplus/deficit indicative of the difference between the setpoint and a threshold Eb/Nt needed for the desired level of performance, or a combination thereof. The metrics may include re-encoded symbol error rate, re-encoded power metric, modified Yamamoto metric, minimum or average LLR among decoded bits, number of decoding iterations, and possibly others. The setpoint may be adjusted in different manners and/or by different amounts depending on the above-noted factors. The techniques may be employed for forward and/or reverse links in CDMA systems.
Type:
Grant
Filed:
July 12, 2004
Date of Patent:
January 5, 2010
Assignee:
QUALCOMM Incorporated
Inventors:
Tao Chen, Jack M. Holtzman, Fuyun Ling, Keith Saints, Nagabhushana Sindhushayana, Charles E. Wheatley, III
Abstract: A compensation circuit to correct for mismatch in a quadrature receiver comprises first and second mixers to receive a radio frequency (RF) modulated signal. One mixer receives an I local oscillator signal while the second mixer receives a Q local oscillator signal wherein the I and Q local oscillators have frequencies that are substantially identical. The output of the first and second mixers are coupled to first and second filters, respectively, which generate the I and Q output signals, respectively. Inherent circuit mismatch generate gain and/or phase errors that result in mismatch in the I and Q output signals. A correction circuit automatically applies a correction factor to at least one of the I and Q output signals to correct the gain and/or phase error by applying a multiplication factor to at least one of the I and Q output signals to thereby generate a corrected signal. The correction factors must be determined on a unit by unit basis.
Type:
Grant
Filed:
May 29, 2002
Date of Patent:
August 31, 2004
Assignee:
Qualcomm Incorporated
Inventors:
Steven C. Ciccarelli, Arun Raghupathy, Robert Reeves
Abstract: A novel and improved method and apparatus for searching is described. This searcher combines the ability to search multiple offsets of single pilots, such as those found in the IS-95 system, with the ability to search multiple pilots, such as those found in a GPS location determination system. Both types of searching can be done in a single architecture combining the parallel computation features of a matched filter with the flexibility of allowing a variable number of coherent accumulations and a variable number of non-coherent accumulations to be performed at high speed for a wide range of search hypotheses in a resource efficient manner. This invention allows for parallel use of the matched filter structure in a time-sliced manner to search multiple windows. In addition, the searcher allows for optional independent Walsh decovering for each search window. The time-sharing approach allows for optional frequency searching of any offset.
Type:
Grant
Filed:
December 21, 1999
Date of Patent:
November 12, 2002
Assignee:
Qualcomm, Incorporated
Inventors:
Gilbert C. Sih, Ian Fevrier, Inyup Kang, Christopher Patrick