Texas Instruments Corporation

University of Washington

Katherine G Brown

Sundararajan Sriram

Yuan Kang Lee

Kirk Watson Beach

Zhenguo Gu

Francis Honore

Zhengou Gu

Melani I Plett

Michael J Caps

Kang Lee

A mechanism for implementing time tracking and early/ontime/late correlation processing in a vector correlator has been implemented to accommodate processing of data when the earliest chips in a triple data input buffer are to be processed and time tracking needs to be done to an earlier sample and further to accommodate processing of data when chips being processed are the last chips in a circular input buffer and time tracking needs to be done to a later sample.

Method of time tracking in a vector correlator based rake receiver

A system and method for maintaining timing in a CDMA rake receiver has a global chip counter that counts CDMA signal chips as they arrive at the CDMA rake receiver. A local pseudo-noise (PN) sequence replica of the incoming CDMA signal is generated and used to perform a sliding window correlation of the locally generated PN sequence replica with the incoming signal to correlate the CDMA signal timing relative to stored CDMA signal chip counts. The PN sequence timing is maintained relative to GCC, which avoids having to keep track of absolute time within each Rake finger.

Method for maintaining timing in a CDMA rake receiver

A slot-aligned IQ data buffer scheme has a third buffer that allows a processing engine to slide the selection of a vector to be processed so that it aligns with the framing of the data. This is particularly advantageous for CDMA and WCDMA systems where there are overlaying coded data streams, each with its own frame timing, since data is processed cleanly at boundaries in the data such that the processing hardware can be minimized. A first level of muxing selects a pair of buffers having the data to be processed from among three buffers. A second level of muxing selects the sample number required. The third level of muxing selects the correct chips for the alignment of the slot. The third stage is implemented with a barrel shifter to minimize hardware generally associated with use of multiplexing.

Triple data system for high data rate communication systems

A programmable, flexible, vector correlation engine for CDMA mobile and base station chip rate signal processing. A correlator co-processor (CCP) performs the de-spreading tasks for a RAKE receiver, early/late correlations for time tracking, and has provision for coherent accumulation of different lengths. The CCP also performs energy estimation and non-coherent accumulation functions. The CCP can also perform correlation functions required for delay profile estimation, and for search/acquisition functions. The same centralized Data Path is used to perform all these functions; a common controller generates signals into the Data Path in response to tasks initiated by a host processor (e.g., DSP). The tasks written into the CCP are performed effectively in parallel by the CCP Data Path.

Correlator co-processor for CDMA RAKE receiver operations

An LFRS (,) calculates a PN sequence using Fibonacci form, such that when an offset is calculated from a known state, the bits of the new state comprise a block of sequence bits. Accordingly, to calculate a block having a length less than the length of the LFSR (,), all bits of the desired block can be calculated in a single offset calculation. If the block has a length greater than the length of the LFSR, one or more additional masks can be used to calculate the additional bits of the block sequence. Zero insertion is also supported.

Block pseudo-noise generating circuit

Phase of each transducer element of a high intensity focused (HIFU) transducer array is controlled to compensate for phase change introduced by varying velocity through differing tissue along a path towards a treatment volume. The echo of a specific harmonic of ultrasound pulses of moderate intensity and less than HIFU intensity are used to measure the propagation path transit time of each HIFU transducer element that will converge in a treatment volume through nonhomogeneous tissue. The moderate intensity is outside the linear region between molecular velocity fluctuations and pressure fluctuations. Thus, specific harmonic echoes are distributed in all directions from the treatment volume. Temporal delay in the specific harmonic echoes provide a measure of the propagation path transit time to transmit a pulse that will converge on the treatment volume.

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Coppell, TX, United States of America

Katherine G Brown