Method and system for determining symbol boundary timing in a multicarrier data transmission system
First Claim
1. A symbol timing unit configured to produce a plurality of difference values for a plurality of different potential symbol timing boundaries, the symbol timing unit comprising:
- a subtractor configured to subtract (1) a first sample value of a first training symbol from (2) a second sample value of a second training symbol to produce a first difference value of the plurality of difference values;
an absolute value circuit configured to calculate absolute value or magnitude;
an accumulator configured to accumulate an absolute value or magnitude of the first difference value with an absolute value or magnitude of a second difference value of the plurality of difference values computed by the absolute value circuit, wherein the second difference value was previously computed;
a controller configured to facilitate repeating of the subtracting in the subtractor and accumulating in the accumulator over at most a factor of a symbol length;
an estimator configured to estimate noise due to inter-carrier and inter-symbol interference for at least one of the plurality of different potential symbol timing boundaries; and
a comparator configured to select, based on the accumulated difference value produced by the accumulator, a choice of symbol boundary timing with substantially a least estimated noise due to inter-carrier and inter-symbol interference.
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Accused Products
Abstract
Improved techniques for acquiring symbol boundary timing at a receiver of a multicarrier data transmission system during a training sequence are disclosed. One aspect is symbol boundary determination at a receiver wherein minimal interference is used as a criterion in selecting from a plurality of potential symbol boundary timings. The symbol boundary determination at the receiver can be performed in a time domain or a frequency domain manner. Another aspect pertains to an improved training sequence wherein pairs of identical symbols are transmitted by a transmitter. These symbols can be supplied to the transmitter in a time domain or a frequency domain manner.
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Citations
20 Claims
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1. A symbol timing unit configured to produce a plurality of difference values for a plurality of different potential symbol timing boundaries, the symbol timing unit comprising:
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a subtractor configured to subtract (1) a first sample value of a first training symbol from (2) a second sample value of a second training symbol to produce a first difference value of the plurality of difference values; an absolute value circuit configured to calculate absolute value or magnitude; an accumulator configured to accumulate an absolute value or magnitude of the first difference value with an absolute value or magnitude of a second difference value of the plurality of difference values computed by the absolute value circuit, wherein the second difference value was previously computed; a controller configured to facilitate repeating of the subtracting in the subtractor and accumulating in the accumulator over at most a factor of a symbol length; an estimator configured to estimate noise due to inter-carrier and inter-symbol interference for at least one of the plurality of different potential symbol timing boundaries; and a comparator configured to select, based on the accumulated difference value produced by the accumulator, a choice of symbol boundary timing with substantially a least estimated noise due to inter-carrier and inter-symbol interference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification