Spread-spectrum telephony with accelerated code acquisition
First Claim
1. A method of spread spectrum communication, comprising the steps of:
- transmitting a signal which at least intermittently includes a data channel spread by a first long code, a first perch channel which is transmitted intermittently and has not been spread by said first long code, and a second perch channel which is transmitted intermittently and has not been spread by said first long; and
wherein multiple transmissions of said first and second perch channels, in combination, provide at least partial identification of said first long code;
wherein said second perch channel comprises symbols of comma free error correcting codes comprising a set of code words from an error correcting code such that each code word has unique cyclic shifts, and the cyclic shifts of each code word are distinct from cyclic shifts of other code words in the set.
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Accused Products
Abstract
The present application discloses an improved mobile communications architecture, in which each base station broadcasts not only data which has been spread by that station'"'"'s long code word, but also (intermittently) code identification data which has not been spread. The code identification data is a block code which includes multiple symbols, so that multiple intermittent transmissions are required to complete the transmission of the code identification data. This transmission lets the mobile station shorten the search for the base station'"'"'s long code word in two ways: the code identification data gives at least some information about the long code itself; and the phase of the block code gives at least some information about the phase of the long code word.
134 Citations
57 Claims
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1. A method of spread spectrum communication, comprising the steps of:
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transmitting a signal which at least intermittently includes a data channel spread by a first long code, a first perch channel which is transmitted intermittently and has not been spread by said first long code, and a second perch channel which is transmitted intermittently and has not been spread by said first long; and
wherein multiple transmissions of said first and second perch channels, in combination, provide at least partial identification of said first long code;
wherein said second perch channel comprises symbols of comma free error correcting codes comprising a set of code words from an error correcting code such that each code word has unique cyclic shifts, and the cyclic shifts of each code word are distinct from cyclic shifts of other code words in the set. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of spread spectrum communication, comprising the steps of:
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transmitting a signal which includes first data which has been spread by a first long code, and which also includes, intermittently, a first perch channel comprising a shared code which does not identify said first long code and a second perch channel consisting of successive portions of a comma-free block code which provides at least partial identification of said first long code, wherein said first and second perch channels are not spread by said first long code;
wherein said symbols of comma free block code comprise a set of code words such that each code word has unique cyclic shifts, and the cyclic shifts of each code word are distinct from cyclic shifts of other code words in the set. - View Dependent Claims (11, 12, 13, 14)
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15. A method for operating a mobile station, comprising the steps of:
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detecting, when possible, a block code that identifies a base station specific scrambling or long code, in the transmission of a new base station with which communication is desired to be established;
deriving at least some information about the possible identity of a long code from said block of symbols in combination; and
deriving at least some information about the phase of said long code from the phase of said block code;
wherein said block code is a comma free error correcting code, comprising a set of code words from an error correcting code such that each code word has unique cyclic shifts, and the cyclic shifts of each code word are distinct from cyclic shifts of other code words in the set. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A method of communication, comprising the steps of:
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providing a plurality of base stations executing a method of spread spectrum communication, comprising the action of transmitting a signal which at least intermittently includes both first data which has been spread by a first base station specific long code, and also second data which is transmitted intermittently, and has not been spread by said first long code; and
providing a plurality of receivers executing a method for operating a mobile station, comprising the steps of;
detecting, when possible, a block code that identifies at least in part said long code, in the transmission of a new base station with which communication is desired to be established; and
deriving at least some information about the possible identity of said long code from said block of symbols in combination; and
deriving at least some information about the phase of said long code from the phase of said block code; and
wherein said second data successively defines portions of a block code which provides at least partial identification of said first code. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A spread spectrum communication system, comprising:
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a base station which transmits a signal, comprising;
first data which has been spread by a first long code;
second data which is transmitted intermittently, and has not been spread by said first long code; and
a block code which provides at least partial identification of said first long code and information about the phase of said first long code and is defined, at least in part by said second data; and
a receiver which receives said signal and said block code;
wherein said block code is a comma free code comprising a set of code words from an error correcting code such that each code word has unique cyclic shifts, and the cyclic shifts of each code word are distinct from cyclic shifts of other code words that comprise the block code. - View Dependent Claims (35, 36, 37, 38, 39)
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40. A spread spectrum communication system, comprising:
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a base station which transmits a signal, comprising;
first data which has been spread by a first long code;
successive portions of a comma-free block code which provide at least partial identification of said first long code and information about the phase of said long code, which is not spread by said first long code; and
a shared code which does not even partially identify said first long code and which is not spread by said first long code; and
a receiver which receives said signal. - View Dependent Claims (41, 42, 43, 44, 45)
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46. A spread spectrum communication system, comprising:
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a base station transmitting a scrambling code and a code-identifying block code that is not spread by said scrambling code; and
a receiver which detects, when possible, a said code-identifying block code that is not spread by the base station specific scrambling code, in the transmission of a signal from said base station with which communication is desired to be established; and
which derives at least some information about the possible identity of the scrambling code used by said base station from said block of symbols in combination; and
derives at least some information about the phase of said scrambling code from the phase of said block code.- View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57)
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Specification