Equaliser apparatus and methods
First Claim
1. An equaliser for a digital communications system, the equaliser comprising:
- a first buffer to store received data prior to equalisation;
a second buffer to store error-checked received data;
a channel estimator coupled to said first and second buffers to determine a channel estimate using said received data from said first buffer and said error-checked data from said second buffer; and
a control unit coupled to said channel estimator to update the channel estimate for use by said equaliser in equalising said received data,wherein said control unit is configured to perform said updating conditional upon a difference between the channel estimate and a previous channel estimate used for equalising said received data; and
a look-up table coupled to said control unit and a calculating device coupled to said look-up table and configured to calculate and store in said look-up table, data for a plurality of symbol sequences, the data for each symbol sequence comprising data obtained by applying said channel estimate to a sequence of symbols.
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Accused Products
Abstract
An equalizer for a digital communications system includes a first buffer to store received data prior to equalisation; a second buffer to store error-checked received data; a channel estimator coupled to the first and second buffers to determine a channel estimate using the received data from the first buffer and the error-checked data from the second buffer; and a control unit coupled to the channel estimator to update a channel estimate for use by the equalizer in equalizing the received data. The control unit performs the updating conditional upon a difference between the channel estimate and a previous channel estimate used for equalizing the received data. A look-up table is coupled to the control unit and a calculating device is coupled to the look-up table to calculate and store, in the look-up table, data obtained by applying the channel estimate to a sequence of symbols.
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Citations
15 Claims
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1. An equaliser for a digital communications system, the equaliser comprising:
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a first buffer to store received data prior to equalisation; a second buffer to store error-checked received data; a channel estimator coupled to said first and second buffers to determine a channel estimate using said received data from said first buffer and said error-checked data from said second buffer; and a control unit coupled to said channel estimator to update the channel estimate for use by said equaliser in equalising said received data, wherein said control unit is configured to perform said updating conditional upon a difference between the channel estimate and a previous channel estimate used for equalising said received data; and a look-up table coupled to said control unit and a calculating device coupled to said look-up table and configured to calculate and store in said look-up table, data for a plurality of symbol sequences, the data for each symbol sequence comprising data obtained by applying said channel estimate to a sequence of symbols. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of equalising data in a digital communication system, the method comprising:
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receiving said data for equalisation; storing said received data in a first buffer; equalising said received data; error-checking said equalised data; storing said error-checked data in a second buffer; reading data from said first and second buffers; determining a channel estimate using said received data and said error-checked equalised data; and updating said channel estimate for use in said equalisation using said determined channel estimate, wherein said updating is conditional upon said channel estimate being different from a channel estimate previously used for said equalising by more than an updating trigger level; and storing said channel estimate in a look-up table as data for a plurality of symbol sequences modified by said channel estimate. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A computer readable medium encoded with program instructions which when executed by a computer results in equalising data in a digital communication system by performance of steps comprising:
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receiving said data for equalisation; storing said received data in a first buffer; equalising said received data; error-checking said equalised data; storing said error-checked data in a second buffer; reading data from said first and second buffers; determining a channel estimate using said received data and said error-checked equalised data; updating a channel estimate for use in said equalisation using said determined channel estimate, wherein said updating is conditional upon said channel estimate being different from a channel estimate previously used for said equalising by more than an updating trigger level; and storing said channel estimate in a look-up table as data for a plurality of symbol sequences modified by said channel estimate.
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Specification