Qualcomm Incorporated

Richard Chi

Parvathanathan Subrahmanya

Da-shan Shiu

Serge D Willenegger

Nitin Kasturi

Chih-Ping Hsu

Jittra Jootar

Avneesh Agrawal

Ranganathan Krishnan

Raganathan Krishnan

Techniques to more efficiently control the transmit power for a data transmission that uses a number of formats (e.g., rates, transport formats). Different formats for a given data channel (e.g., transport channel) may require different target SNIRs to achieved a particular BLER. In one aspect, individual target BLER may be specified for each format of each data channel. In another aspect, various power control schemes are provided to achieve different target SNIRs for different formats. In a first power control scheme, multiple individual outer loops are maintained for multiple formats. For each format, its associated outer loop attempts to set the target SNIR such that the target BLER specified for that format is achieved. In a second power control scheme, multiple individual outer loops are maintained and the base station further applies different adjustments to the transmit power levels for different formats.

Power control for a channel with multiple formats in a communication system

Techniques for detecting received sequences when certain signaling characteristics (e.g., transport formats, rates) are not known a priori at the receiver. In one method, a sequence for a transmitted message is received, and a metric value is computed for each of a number of hypothesized messages corresponding to a number of hypotheses for the unknown signaling characteristic of the transmitted message. The metric value is computed based on a MAP metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages. The hypothesized message having the best metric value is selected as the transmitted message. The specific form of the MAP metric is dependent on the particular signaling scheme used to map the message to its corresponding sequence, and may be used for blind transport format detection (BTFD) in a W-CDMA system and blind rate detection in an IS-95 CDMA system.

Method and apparatus for detecting messages with unknown signaling characteristic

Techniques for power control that avoids outer loop wind-up are disclosed. In one aspect, wind-up of a target power level is detected, and the target power level is modified in response. In another aspect, unwinding of the target power level is detected, after which the target power level is determined without considering wind-up. Various other aspects are also presented, including wind-up and unwinding detection procedures, and target power level modification procedures. These aspects have the benefit of reducing the time that transmit power exceeds that which is necessary, thus increasing system capacity and performance, and mitigating misallocation of system resources.

Power control avoiding outer loop wind-up

A trellis decoder determines the most likely transmitted phase in response to previously requested phase adjustments and observed transmitted symbols. Maximum a posteriori (MAP) decoding also may be used. Alternatively, the identified likely transmitted phase is used for data demodulation. This and related features have the benefit of decreasing the effect of phase discrepancies introduced by erroneous reception of phase adjustment information, resulting in improved error rates, and a corresponding increase in system capacity, data throughput, or both.

Closed loop transmit diversity antenna verification using trellis decoding

A received symbol stream is oversampled and correlated with a known sync word to determine the correlation properties of the oversampled signal with a known sync word. A linear filter, such as a moving average window filter, is convolved with the correlation signal to generate a convolution signal. Once the convolution signal has reached a predetermined threshold, it is scanned over a predetermined window of oversamples. If the convolution signal exceeds the threshold for the window of oversamples, the sync word has been found and the symbol stream is down-sampled at intervals that depend on the data rate of the symbol stream. This down-sampling process may be done by picking the center oversample corresponding to each information symbol given the timing alignment, or by doing a majority vote over a multiple number of samples centered around the center oversample.

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Santa Clara, CA, United States of America

Richard Chi