Method to indicate synchronization lock of a remote station with a base station for a discrete multitone spread spectrum communications system
First Claim
1. A time division duplex method of synchronizing a remote station to a base station in a bandwidth efficient communication system, comprising the steps of:
- generating a clock signal at the base station;
deriving a synchronization symbol pattern from said base station clock signal;
spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal;
transmitting the spread signal from the base station;
receiving the spread signal at the remote station;
generating a first clock signal at the remote station;
sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal;
applying said first sampled signal to a matched filter bank, forming a frequency error signal;
adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal;
sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal;
despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern;
comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and
selectively processing traffic signals received from the base station using said second clock signal, if said comparing step is successful.
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Accused Products
Abstract
A method for a wireless discrete multitone spread spectrum communications system, synchronizes the remote station to the base station. The method begins with the step of generating a clock signal at the base station. The base station then derives a synchronization symbol pattern from the base station clock signal and spreads the it with spreading codes that distributes the symbol pattern over a plurality of discrete tones, forming a discrete multitone spread spectrum signal. The base station then transmits the spread signal to the remote station. The remote station generates a first clock signal and samples the discrete tones using the remote station first clock signal, forming a first sampled signal. Then the remote station applies the first sampled signal to a matched filter bank, forming a frequency error signal. The method then adjusts a frequency of the remote station first clock signal using the frequency error signal, forming a second clock signal. Then the remote station samples the discrete tones using the remote station second clock signal, forming a second sampled signal. Then the remote station despreads the second sampled signal with despreading codes to extract the synchronization symbol pattern. Then the remote station compares the extracted synchronization symbol pattern with a reference symbol pattern at the remote station. If the comparing step is successful, then the remote station selectively processes traffic signals received from the base station using the second clock signal. If the comparing step is not successful, then the remote station selectively adjusts a time offset value of the remote station second clock signal forming a third clock signal.
48 Citations
34 Claims
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1. A time division duplex method of synchronizing a remote station to a base station in a bandwidth efficient communication system, comprising the steps of:
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generating a clock signal at the base station; deriving a synchronization symbol pattern from said base station clock signal; spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; transmitting the spread signal from the base station; receiving the spread signal at the remote station; generating a first clock signal at the remote station; sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; applying said first sampled signal to a matched filter bank, forming a frequency error signal; adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and selectively processing traffic signals received from the base station using said second clock signal, if said comparing step is successful. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A time division duplex method of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system, comprising the steps of:
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generating a clock signal at the base station; deriving a synchronization symbol pattern from said base station clock signal; spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; transmitting the spread signal from the base station and receiving the spread signal at the remote station; generating a first clock signal at the remote station; sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; forming a frequency error signal from said first sampled signal; adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and selectively processing traffic signals received from the base station using said second clock signal, if said comparing step is successful. - View Dependent Claims (10, 11, 12)
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13. A time division duplex method of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system to enable communication of data traffic, comprising the steps of:
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generating a clock signal at the base station; deriving a synchronization symbol pattern from said base station clock signal; spectrally and spatially spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; including traffic data in the spread signal by spectrally and spatially spreading the traffic data the base station said spreading codes to distribute the traffic data over a plurality of discrete tones transmitting the spread signal from the base station and receiving the spread signal at the remote station; generating a first clock signal at the remote station; sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; forming a frequency error signal from said first sampled signal; adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and despreading said traffic data with said despreading codes to extract said traffic data from said spread signal using said second clock signal, and outputting said traffic data if said comparing step is successful. - View Dependent Claims (14)
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15. A system of synchronizing a remote station to a base station in a bandwidth efficient communication system, comprising:
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means for generating a clock signal at the base station; means for deriving a synchronization symbol pattern from said base station clock signal; means for spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; means for transmitting the spread signal from the base station; means for receiving the spread signal at the remote station; means for generating a first clock signal at the remote station; means for sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; means for applying said first sampled signal to a matched filter bank, forming a frequency error signal; means for adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; means for sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; means for despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; means for comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and means for selectively processing traffic signals received from the base station using said second clock signal, if said comparing is successful. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A system of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system, comprising:
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means for generating a clock signal at the base station; means for deriving a synchronization symbol pattern from said base station clock signal; means for spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; means for transmitting the spread signal from the base station and receiving the spread signal at the remote station; means for generating a first clock signal at the remote station; means for sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; means for forming a frequency error signal from said first sampled signal; means for adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; means for sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; means for despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; means for comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and means for selectively processing traffic signals received from the base station using said second clock signal, if said comparing is successful. - View Dependent Claims (24, 25, 26)
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27. A system of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system to enable communication of data traffic, comprising:
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means for generating a clock signal at the base station; means for deriving a synchronization symbol pattern from said base station clock signal; means for spectrally and spatially spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; means for including traffic data in the spread signal by spectrally and spatially spreading the traffic data the base station said spreading codes to distribute the traffic data over a plurality of discrete tones means for transmitting the spread signal from the base station and receiving the spread signal at the remote station; means for generating a first clock signal at the remote station; means for sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; means for forming a frequency error signal from said first sampled signal; means for adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; means for sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; means for despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; means for comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and means for despreading said traffic data with said despreading codes to extract said traffic data from said spread signal using said second clock signal, and outputting said traffic data if said comparing is successful. - View Dependent Claims (28)
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29. A time division duplex method of synchronizing a remote station to a base station in a bandwidth efficient communication system, comprising the steps of:
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generating a clock signal at the base station; deriving a synchronization symbol pattern from said base station clock signal; spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; transmitting the spread signal from the base station in a first time division duplex period; receiving the spread signal at the remote station; generating a first clock signal at the remote station; sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; applying said first sampled signal to a matched filter bank, forming a frequency error signal; adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and selectively processing traffic signals received from the base station in a later time division duplex period using said second clock signal, if said comparing step is successful.
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30. A time division duplex method of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system, comprising the steps of:
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generating a clock signal at the base station; deriving a synchronization symbol pattern from said base station clock signal; spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; transmitting the spread signal from the base station and receiving the spread signal at the remote station during a first time division duplex period; generating a first clock signal at the remote station; sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; forming a frequency error signal from said first sampled signal;
adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal;sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and selectively processing traffic signals received from the base station during a later time division duplex period using said second clock signal, if said comparing step is successful.
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31. A time division duplex method of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system to enable communication of data traffic, comprising the steps of:
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generating a clock signal at the base station; deriving a synchronization symbol pattern from said base station clock signal; spectrally and spatially spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; including traffic data in the spread signal by spectrally and spatially spreading the traffic data the base station said spreading codes to distribute the traffic data over a plurality of discrete tones transmitting the spread signal from the base station and receiving the spread signal at the remote station during a first time division duplex period; generating a first clock signal at the remote station; sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; forming a frequency error signal from said first sampled signal;
adjusting a frequency of said remote station first clock signal using said frequency error signal;forming a second clock signal; sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and despreading said traffic data with said despreading codes to extract said traffic data from said spread signal using said second clock signal, and outputting said traffic data if said comparing step is successful.
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32. A time division duplex system of synchronizing a remote station to a base station in a bandwidth efficient communication system, comprising:
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means for generating a clock signal at the base station; means for deriving a synchronization symbol pattern from said base station clock signal; means for spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; means for transmitting the spread signal from the base station during a first time division duplex period; means for receiving the spread signal at the remote station;
means for generating a first clock signal at the remote station;means for sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; means for applying said first sampled signal to a matched filter bank, forming a frequency error signal; means for adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; means for sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; means for despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; means for comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and means for selectively processing traffic signals received from the base station using said second clock signal in a later time division duplex period, if said comparing is successful.
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33. A time division duplex system of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system, comprising:
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means for generating a clock signal at the base station; means for deriving a synchronization symbol pattern from said base station clock signal; means for spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; means for transmitting the spread signal from the base station and receiving the spread signal at the remote station during a first time division duplex period; means for generating a first clock signal at the remote station; means for sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; means for forming a frequency error signal from said first sampled signal; means for adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal, means for sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; means for despreading said second sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; means for comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and means for selectively processing traffic signals received from the base station using said second clock signal in a later time division duplex period, if said comparing is successful.
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34. A time division duplex system of synchronizing a remote station to a base station in a wireless discrete multitone spread spectrum communications system to enable communication of data traffic, comprising:
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means for generating a clock signal at the base station; means for deriving a synchronization symbol pattern from said base station clock signal; means for spectrally and spatially spreading said synchronization symbol pattern at the base station with spreading codes that distributes the synchronization symbol pattern over a plurality of discrete tones, forming a spread signal; means for including traffic data in the spread signal by spectrally and spatially spreading the traffic data the base station said spreading codes to distribute the traffic data over a plurality of discrete tones; means for transmitting the spread signal from the base station and receiving the spread signal at the remote station during a first time division duplex period; means for generating a first clock signal at the remote station; means for sampling said discrete tones at the remote station using said remote station first clock signal, forming a first sampled signal; means for forming a frequency error signal from said first sampled signal; means for adjusting a frequency of said remote station first clock signal using said frequency error signal, forming a second clock signal; means for sampling said discrete tones at the remote station using said remote station second clock signal, forming a second sampled signal; means for despreading said second-sampled signal at the remote station with despreading codes to extract said synchronization symbol pattern; means for comparing said extracted synchronization symbol pattern with a reference symbol pattern at the remote station; and means for despreading said traffic data with said despreading codes to extract said traffic data from said spread signal using said second clock signal in a later time division duplex period, and outputting said traffic data if said comparing is successful.
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Specification