Spread-spectrum, frequency-hopping radiotelephone system
First Claim
1. In a frequency hopping multiple access communications system in which a set of N carrier frequencies are used to provide frequency hopping communications channels in said system, said system including:
- means for defining a plurality of adjacent communications sites associated with said communications system;
means using said N carrier frequencies for defining a first set of frequency hopping communications channels associated with a first of said plurality of adjacent communications sites in which no two of said channels in said first set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time;
means using said N carrier frequencies for defining a second set of frequency hopping communications channels associated with a second of said plurality of adjacent communications sites in which no two of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time;
said second set of channels is further defined so that no one of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time as more than a predetermined number of said channels in said first set of frequency hopping communications channels;
where said predetermined number is the minimum number of channels possible;
means for selectively encoding digital information signals on ones of said frequency hopping communications channels such that there is a redundant relationship between channel bits;
error correcting means for setting said relationship; and
decoder means for utilizing said relationship for error correction.
1 Assignment
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Accused Products
Abstract
A multiple access communications system reuses a set of N carrier frequencies in adjacent communications sites to provide more than N minimally cross-correlated frequency-hopping communications channels. A first set of communications channels is associated with a first of the communications sites. No two of the channels in the first set employ the same frequency at the same time. A second set of communications channels is associated with a second of the adjacent communications sites. No two of the channels in the second set of channels employ the same one of the N carrier frequencies at the same time. One or more sets of the minimally cross-correlated channels are further defined so that none of the channels in such sets employ the same frequency at the same time as more than a predetermined number of the channels in another of the sets of the minimally cross-correlated frequency-hopping communications channels.
93 Citations
15 Claims
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1. In a frequency hopping multiple access communications system in which a set of N carrier frequencies are used to provide frequency hopping communications channels in said system, said system including:
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means for defining a plurality of adjacent communications sites associated with said communications system; means using said N carrier frequencies for defining a first set of frequency hopping communications channels associated with a first of said plurality of adjacent communications sites in which no two of said channels in said first set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; means using said N carrier frequencies for defining a second set of frequency hopping communications channels associated with a second of said plurality of adjacent communications sites in which no two of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; said second set of channels is further defined so that no one of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time as more than a predetermined number of said channels in said first set of frequency hopping communications channels;
where said predetermined number is the minimum number of channels possible;means for selectively encoding digital information signals on ones of said frequency hopping communications channels such that there is a redundant relationship between channel bits; error correcting means for setting said relationship; and decoder means for utilizing said relationship for error correction. - View Dependent Claims (2, 4)
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3. In a frequency hopping multiple access communications system in which a set of N carrier frequencies are used to provide frequency hopping communications channels in said system, said system including:
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means for defining a plurality of adjacent communications sites associated with said communications system; means using said N carrier frequencies for defining a first set of frequency hopping communications channels associated with a first of said plurality of adjacent communications sites in which no two of said channels in said first set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; means using said N carrier frequencies for defining a second set of frequency hopping communications channels associated with a second of said plurality of adjacent communications sites in which no two of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; said second set of channels is further defined so that no one of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time as more than a predetermined number of said channels in said first set of frequency hopping communications channels;
where said predetermined number is the minimum number of channels possible;voice activity detection means for measuring signal activity levels representative of subscriber voice activity on an assigned channel to generate a channel voice activity signal; and means responsive to said channel voice activity signal for selectively allocating channels to subscribers.
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5. In a frequency hopping multiple access communications system in which a set of N carrier frequencies are used to provide frequency hopping communications channels in said system, said system including:
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means for defining a plurality of adjacent communications sites associated with said communications system; means using said N carrier frequencies for defining a first set of frequency hopping communications channels associated with a first of said plurality of adjacent communications sites in which no two of said channels in said first set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; and means using said N carrier frequencies for defining a second set of frequency hopping communications channels associated with a second of said plurality of adjacent communications sites in which no two of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time;
wherein said second set of frequency hopping communications channels is further defined as a first decimated transformation of said frequency hopping communications channels in said first set. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. In a method of providing a frequency hopping multiple access communications system in which a set of N carrier frequencies are used to provide frequency hopping communications channels in said system, said method including:
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defining a plurality of adjacent communications sites associated with said communications system; using said N carrier frequencies for defining a first set of frequency hopping communications channels associated with a first of said plurality of adjacent communications sites in which no two of said channels in said first set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; and using said N carrier frequencies for defining a second set of frequency hopping communications channels associated with a second of said plurality of adjacent communications sites in which no two of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time, wherein said second set of frequency hopping communications channels is a first decimated transformation of each of said frequency hopping communications channels in said first set. - View Dependent Claims (13)
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14. In a frequency hopping multiple access communications system in which a set of N carrier frequencies are used to provide frequency hopping communications channels in said system, said system including:
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a plurality of adjacent communications sites associated with said communications system; and a central base communications station which uses said N carrier frequencies for defining a first set of frequency hopping communications channels associated with a first of said plurality of adjacent communications sites in which no two of said channels in said first set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time; and
which also uses said N carrier frequencies for defining a second set of frequency hopping communications channels associated with a second of said plurality of adjacent communications sites in which no two of said channels in said second set of frequency hopping communications channels employ the same one of said N carrier frequencies at the same time, wherein said second set of frequency hopping communications channels is further defined as a first decimated transformation of each of said frequency hopping communications channels in said first set. - View Dependent Claims (15)
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Specification