Qualcomm Incorporated

Mohammad Jafar Mohseni

Brian K Butler

Haitao Zhang

Deepu John

Roland Reinhard Rick

Helena Deirdre O'Shea

Faraz Faheem

A system and method for bad frame indication of a speech frame includes estimating a signal-to-noise ratio (SNR) and checking a cyclic redundancy code (CRC) value of the speech frame. When the speech frame fails CRC error detection or the SNR is below a pre-specified value, a bad frame indication (BFI) flag is set. When the speech frame passes CRC error detection and the SNR is above the pre-specified value, a receive signal quality metric of the speech frame is checked against a high threshold and, if need be, a low threshold. The BFI flag and the receive signal quality metric for the previous speech frame is checked when the current receive signal quality metric is between the high and low thresholds. The BFI flag is set according to the value of the SNR, the CRC value, the current and previous receive signal quality metrics, and the previous BFI flag.

Bad frame indicator for radio-telephone receivers in GSM mobile systems

A composite signal has two components, each carrying a stream of information that may be digital. In one application of a method according to an embodiment of the invention, at least one of the components is delayed such that a time relation between the streams of information is altered. The components are transferred via a common signal path such that upon transfer, the original time relation between the streams of information may be restored.

System, method, and apparatus for fractional delay

A spreading system according to an embodiment of the invention spreads two data signals. The system produces a filtered signal that is based on one of the data signals and an output signal that is based on both of the data signals. In one example, a spreading system is used to perform QPSK spreading of two data signals, including separate processing of the two data signals, in a practical manner. Such separate control may include filtering and/or gain control.

System for direct sequence spreading

A system for digital filtering includes a set of logic gates, a state storage, and a multiplexer. The state storage includes two or more storage banks and may also include combinatorial logic and/or at least one lookup table. In one application, a filtering operation according to a finite-impulse-response filter coefficient vector is performed without runtime multiplications. Applications to symmetric and antisymmetric filter coefficient vectors are described, as well as applications to filter coefficient vectors of arbitrary odd or even length.

Digital filter with state storage

In applications employing phase-shift keying modulation, a phase rotator as disclosed herein is used to rotate the constellation of signal vectors before carrier modulation in order to maximize modulator output power. Such a rotator may be applied in the digital domain (to complex signals having either binary-valued or multi-valued components) or in the analog domain.

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San Diego, CA, United States of America

Mohammad Jafar Mohseni