Code synchronization unit and method
First Claim
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1. A pilot acquisition unit for a code division multiple access (CDMA) communication system, the pilot acquisition unit comprising:
- a. a fast Hadamard transform (FHT) unit for determining the quality, in accordance with a metric, of each of a set of possible pseudo-random number (PN) loadings; and
b. a pre-Hadamard processing unit for generating a vector u per set of PN loadings, said vector u defining a quality metric of a received pilot signal with said set of possible PN loadings, said pre-Hadamard processing unit providing said vector u to said FHT unit.
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Abstract
A pilot acquisition unit for code division multiple access (CDMA) communication systems is provided which includes a fast Hadamard transform (FHT) unit and a pre-Hadamard processing unit. The FHT unit determines the quality, in accordance with a metric, of each of a set of possible pseudo-random number (PN) loadings and the pre-Hadamard processing unit generates a vector u per set of PN loadings. The vector u defines a quality metric of a received pilot signal with the set of possible PN loadings, the pre-Hadamard processing unit providing the vector u to the FHT unit.
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Citations
25 Claims
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1. A pilot acquisition unit for a code division multiple access (CDMA) communication system, the pilot acquisition unit comprising:
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a. a fast Hadamard transform (FHT) unit for determining the quality, in accordance with a metric, of each of a set of possible pseudo-random number (PN) loadings; and b. a pre-Hadamard processing unit for generating a vector u per set of PN loadings, said vector u defining a quality metric of a received pilot signal with said set of possible PN loadings, said pre-Hadamard processing unit providing said vector u to said FHT unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A code synchronization unit for synchronizing to received encoded signals having frequency drift therein, the code synchronization unit comprising:
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a. a fast Hadamard transform (FHT) unit for determining the quality, in accordance with a metric, of each of a set of possible pseudo-random number (PN) loadings; and b. a pre-Hadamard processing unit for generating a vector u per set of possible PN loadings, said vector u defining a quality metric of said received encoded signal with said set of possible PN loadings, said pre-Hadamard processing unit providing said vector u to said FHT unit. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. An error correcting code decoder for decoding signals having frequency drift therein, the decoder comprising:
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a. a fast Hadamard transform (FHT) unit for determining the quality, in accordance with a metric, of each of a set of possible messages; and b. a pre-Hadamard processing unit for generating a vector u per set of possible PN loadings, said vector u defining a quality metric of said received encoded signal with said set of possible messages, said pre-Hadamard processing unit providing said vector u to said FHT unit. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A method for synchronizing to pilot signals of a code division multiple access (CDMA) communication system, the method comprising the steps of:
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a. per a set of possible PN loadings; i) loading a local PN generator with an initial PN loading; ii) looping on each of the datapoints of said received pilot signal, said step of looping including the steps of; a) combining one partial possible loading sE with a datapoint of said received pilot signal and with a PN loading produced by said local PN generator thereby to update a u vector; and b) stepping said local PN generator to produce another PN loading; iii) performing a fast Hadamard transform on said u vector to determine the quality, in accordance with a metric, of each of said set of possible PN loadings; iv) selecting the PN loading having the best value for its metric; b. repeating steps i-iv for all sets of PN loadings; and c. selecting the PN loading with the best metric from among the PN loadings selected in step iv.
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23. A method for synchronizing to pilot signals of a code division multiple access (CDMA) communication system which have frequency drift therein, the method comprising the steps of:
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a. per a set of possible PN loadings; i) looping over plurality of drift loop values, the step of looping including the steps of; a) loading a local PN generator with a different initial PN loading per loop value; and b) generating an input signal from a received pilot signal which is insensitive to drift; ii) looping on each of the datapoints of said input signal, said second step of looping including the steps of; a) combining one partial possible loading sE with a datapoint of said input signal and with a PN loading produced by said local PN generator thereby to update a u vector; and b) stepping said local PN generator to produce another PN loading; iii) performing a fast Hadamard transform on said u vector to determine the quality, in accordance with a metric, of each of said set of possible PN loadings; iv) selecting the PN loading having the best value for its metric; b. repeating steps i-iv for all sets of PN loadings; and c. selecting the PN loading with the best metric from among the PN loadings selected in step iv.
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24. A method for synchronizing to received encoded signals having frequency drift therein, the method comprising the steps of:
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a. per a set of possible PN loadings; i) looping over plurality of drift loop values, the step of looping including the steps of; a) loading a local PN generator with a different initial PN loading per loop value; and b) generating an input signal from a received pilot signal which is insensitive to drift; ii) looping on each of the datapoints of said input signal, said second step of looping including the steps of; a) combining one partial possible loading sE with a datapoint of said input signal and with a PN loading produced by said local PN generator thereby to update a u vector; and b) stepping said local PN generator to produce another PN loading; iii) performing a fast Hadamard transform on said u vector to determine the quality, in accordance with a metric, of each of said set of possible PN loadings; iv) selecting the PN loading having the best value for its metric; b. repeating steps i-iv for all sets of PN loadings; and c. selecting the PN loading with the best metric from among the PN loadings selected in step iv.
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25. A method for decoding signals having messages therein and being encoded with error correcting codes, the signals having frequency drift therein, the method comprising the steps of:
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a. per a set of possible messages; i) looping over plurality of drift loop values l, the step of looping including the steps of; a) creating a combined generating vector formed from two generating vectors a distance l apart; and b) generating an input signal from a received pilot signal which is insensitive to drift; ii) looping on each of the datapoints of said input signal, said second step of looping including the step of; a) combining one partial possible message sE with a datapoint of said input signal and with an external portion of said combined generating vector thereby to update an element of said u vector defined by an internal portion of said combined generating vector; iii) performing a fast Hadamard transform on said u vector to determine the quality, in accordance with a metric, of each of said set of possible messages; iv) selecting the message having the best value for its metric; b. repeating steps i-iv for all sets of messages; and c. selecting the message with the best metric from among the messages selected in step iv.
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Specification