DELAY ESTIMATION BASED ON REDUCED DATA SETS
First Claim
1. An apparatus comprising:
- a delay estimation unit configured to receive first and second data streams and produce respective first and second filtered data streams;
wherein the delay estimation unit includes a first decimator configured to reduce a number of samples in the first filtered data stream to produce first decimated data, wherein the delay estimation unit includes a second decimator configured to reduce a number of samples in the second filtered data stream to produce second decimated data; and
wherein the delay estimation unit is configured to perform a correlation of the first decimated data with the second decimated data to output an indication of a time alignment of the first data stream relative to the second data stream.
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Abstract
A delay estimation unit is disclosed. The delay estimation unit may receive first and second streams of data having identical content. The amount of data in the data streams is reduced by filtering (e.g., lowpass filtering) the first and second data streams to produce first and second filtered streams, respectively. The amount of data is further reduced by decimating the first and second filtered streams, discarding all but one of every N samples to produce first and second decimated data, respectively. The first and second decimated streams are received by a correlator that performs a correlation operation. The output of the correlator is received by a peak search unit that analyzes the correlation results over time and searches for peaks that indicate alignment of the first and second data streams.
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Citations
19 Claims
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1. An apparatus comprising:
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a delay estimation unit configured to receive first and second data streams and produce respective first and second filtered data streams; wherein the delay estimation unit includes a first decimator configured to reduce a number of samples in the first filtered data stream to produce first decimated data, wherein the delay estimation unit includes a second decimator configured to reduce a number of samples in the second filtered data stream to produce second decimated data; and wherein the delay estimation unit is configured to perform a correlation of the first decimated data with the second decimated data to output an indication of a time alignment of the first data stream relative to the second data stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method comprising:
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a delay estimation unit receiving first and second data streams; lowpass filtering the first and second data streams to produce first and second filtered data streams; first and second decimators reducing a number of samples of the first and second filtered data streams, respectively, to produce corresponding first and second decimated data streams; a correlation unit correlating the first and second decimated data streams; and providing an indication of a time alignment of the first and second data streams based on said correlating. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A delay estimation unit comprising:
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a first filter configured to produce first filtered data by filtering a first data stream; a second filter configured to produce second filtered data by filtering a second data stream, wherein the first and second data streams included information from simulcast analog and digital radio signals, respectively; a first decimator configured to produce first decimated data by outputting 1 of every N samples of the first filtered data; a second decimator configured to output second decimated data by outputting 1 of every N samples of the second filtered data; a correlation unit configured to perform a correlation of the first decimated data with the second decimated data and configured to output an indication of a time alignment of the first data stream relative to the second data stream based on the correlation. - View Dependent Claims (17, 18, 19)
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Specification