Iterative carrier phase tracking decoding system
AssigneeConexant Systems, Inc.
InventorsDonald Brian Eidson, Abraham Krieger
Life of this patent
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Abstract
An iterative system for performing carrier phase tracking of symbols using a serial turbo decoder. Estimates of a buffered block of symbols are provided by a serial turbo decoder. Optionally, reliability metrics for the estimates are provided as well. Responsive to this information, a tracking loop module determines derotation phases for each of the symbols in the buffer. A symbol derotator derotates each of the buffered symbols in the block by its corresponding derotation phase. The derotated symbols are stored back in the buffer. The process may repeat itself for a prescribed number of iterations, after which the serial turbo decoder provides estimates of the underlying source bits.
Claims39
An iterative carrier phase tracking decoding system comprising:
- a buffer for buffering a block of symbols;
- a serial turbo decoder for providing, during an iteration p, estimates skp of one or more of the buffered symbols, rkp, and having a capability to provide one or more reliability metrics Rkp, for the one or more estimates, and, after a prescribed number of iterations, estimates of underlying source bits;
- a tracking loop module configured, during an iteration p, to (a) determine one or more residuals zkp, between the one or more buffered symbols, rkp, and the corresponding one or more symbol estimates, skp;
- (b) weight the residuals with corresponding reliability metrics, Rkp;
- and (c) determine one or more derotation phases θkp responsive to one or more of the weighted or unweighted residuals;
- a symbol derotator for derotating, during an iteration p, one or more of the buffered symbols, rkp, using the one or more derotation phases, θkp, and storing one or more of the derotated symbols, tkp, back in the buffer;
- and
- a controller for directing the system to perform one or more iterations.
An iterative carrier phase tracking decoding system comprising:
- buffer means for buffering a block of symbols;
- serial turbo decoding means for providing, during an iteration p, one or more estimates skp of one or more of the buffered symbols rkp, and having a capability to provide one or more reliability metrics Rkp, for the one or more estimates, and, after a prescribed number of iterations, estimates of underlying source bits;
- tracking loop means for, during an iteration p, (a) determining one or more residuals zkp between one or more of the buffered symbols, rkp and one or more corresponding symbol estimates, skp;
- (b) weighting the one or more residuals with one or more corresponding reliability metrics, Rkp;
- and (c) determining one or more derotation phases θkp, responsive to one or more of the weighted or unweighted residuals;
- symbol derotation means for derotating, during an iteration p, one or more of the buffered symbols, rkp, using one or more derotation phases, θkp, and storing one or more derotated symbols, tkp, back in the buffer;
- and
- control means for directing the system to perform one or more iterations.
A method of performing iterative decoding, comprising the following steps:
- providing one or more estimates skp of a block of buffered symbols rkp;
- providing one or more reliability metrics Rkp for corresponding one or more estimates;
- determining one or more residuals zkp between one or more buffered symbols rkp and one or more symbol estimates skp;
- weighting one or more residuals zkp with one or more reliability metrics Rkp;
- determining one or more derotation phases θkp responsive to one or more of the weighted or unweighted residuals;
- derotating one or more buffered symbols rkp using one or more derotation phases θkp;
- buffering one or more derotated symbols tkp;
- if a prescribed number of iterations has not been completed, performing another iteration beginning with the first providing step;
- and
- after a prescribed number of iterations has been completed, providing estimates of underlying source bits.
A method of performing iterative decoding, comprising the following steps:
- a step of providing one or more estimates skp of one or more buffered symbols rkp;
- a step of providing one or more reliability metrics Rkp for one or more estimates;
- a step of determining one or more residuals zkp between one or more buffered symbols rkp and corresponding one or more symbol estimates skp;
- a step of weighting one or more residuals zkp with one or more corresponding reliability metrics Rkp;
- a step of determining one or more derotation phases θkp responsive to one or more of the weighted or unweighted residuals;
- a step of derotating one or more buffered symbols rkp using one or more derotation phases θkp;
- a step of buffering one or more derotated symbols tkp;
- if a prescribed number of iterations has not been completed, a step of performing another iteration beginning with the first providing step;
- and
- after a prescribed number of iterations has been completed, a step of providing estimates of underlying source bits.
Dependencies are inferred from the claim text.