Agere Systems Inc.

Dominic Wing-Kin Yip

Christopher John Nicol

Tomasz Thomas Prokop

Tomasz Prokop

Rami Banna

Long Ung

Christopher J Nicol

Tomasz T Prokop

A communications circuit includes a filter module with a sampling window, a control module, and an input buffer. The control module has a ray parameter interface to obtain information regarding significant ray changes that make it desirable to re-position the sampling window. The control module determines re-positioning parameters, responsive to this information, which reflect the re-positioning of the sampling window. The input buffer obtains samples of a received signal and outputs received signal data to the filter module. The filter module obtains the re-positioning parameters from the control module, and the filter module and control module temporally re-position the sampling window in duration and/or location in accordance with the re-positioning parameters, and output a filtered chip.

Communications circuit and method with re-positionable sampling span

A communications circuit can operate with a data channel and a control channel. A changeable portion of the circuit can be reconfigurable between a first mode associated with activity on the control channel only and a second mode associated with activity on both the data channel and the control channel. The first mode can be selected to reduce power consumption compared to the second mode. Controller circuitry is provided to sense signals associated with the control channel and to switch the changeable portion between the first and second modes.

Reconfigurable communications circuit operable with data channel and control channel

The span of a linear transversal equalizer filter moves according to the current positions of the multi-paths to a receiver. The alignment of the filter span is measured quantitatively with respect to the current positions of the multi-paths. Adjustments are made to the filter span to enable the linear transversal filter to capture most of the available energy of the transmitted signal. The low-pass-filtered magnitudes of tap weights of the linear filter are multiplied with values of a function which has zeroes at desired points for the larger tap weights, and a gradient of the function at its zeroes being non-zero. The magnitude of the alignment measurement signal is used as a quantitative measure of the alignment of the equalizer span, while the sign of the alignment measurement signal can be used to decide the direction that the span should be moved in.

Measurement of equalizer span alignment with respect to channel condition

A communications circuit can operate in a first mode, such as a diversity mode including space time transmit diversity (STTD). In this mode, a number of equalizer filter portions connected to a number of post-equalizer processors are employed. When the diversity mode is not required, the extra equalizer filter portions would represent a waste of power consumption and/or chip space. A combining circuit and suitable control circuitry are provided to allow use of the additional equalizer filter portions to be made in other operating modes. Appropriate trade-offs can be made based on power consumption and performance.

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Carlingford, Australia

Dominic Wing-Kin Yip