Multiplexed radio communication system

• US 5,737,358 A
• Filed: 02/02/1995
• Issued: 04/07/1998
• Est. Priority Date: 11/03/1992
• Status: Expired due to Fees

• Current Assignee: Geotek Communications, Inc.
• Original Assignee: Geotek Communications, Inc., Rafael - Armament Development Authority Ltd.
• Inventors: Livneh, Noam, Hilsenrath, Oliver, Silbershatz, Giora, Calhoun, George, Ritz, Mordechai
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US08/382,631
• Time in Patent Office: 1,160 Days
• Field of Search: 375/202, 375/262, 375/341, 375/205, 375/260, 375/203, 455/33.1, 455/53.1, 455/54.1, 370/18, 370/95.1, 370/95.3, 370/319, 370/321, 370/203, 370/442, 370/341, 371/43, 379/59
• US Class Current: 375/133
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/7143 Arrangements for generation of hop patterns
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04B 7/2615 using hybrid frequency-time division multiple access [FDMA-TDMA]
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A multiple access communications system reuses a set of either N carrier frequencies or time slots in adjacent communications sites to provide more than N or T minimally cross-correlated frequency or time hopping communications channels respectively. 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 or T time slots 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 or T time slots 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. This is accomplished by having such other sets be a decimated transformation of the first or second set respectively.

Claims

1. A method of providing hopping communication channels in a hopping multiple access communications system in which a set of R communications resources are used to provide said hopping communications channels, said method including:

defining a plurality of adjacent communications sites associated with said communications system;

using said R communication resources to define a first set of 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 hopping communications channels employ the same one of said R communications resources at the same time; and

using said R communications resources to define a second set of 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 hopping communications channels employ the same one of said R communications resources at the same time, said second set of hopping communications channels being a first decimated transformation of each of said hopping communications channels in said first set.

2. The method of claim 1 further comprising:

using said R communications resources to define a third set of hopping communications channels associated with a third of said plurality of adjacent communications sites in which no two of said channels in said third set of hopping communications channels employ the same one of said R communications resources at the same time, said third set of said hopping communications channels being a second decimated transformation of each of said hopping communications channels in said first set.

3. The multiple access communications system as defined in claim 1 in which each of said hopping communications channels in said first set is defined by a unique sequence of said R communications resources and said first decimated transformation is performed on each of said hopping communications channels in said first set by selecting one of said R communications resources from each of said hopping communications channels in said first set in their sequential order skipping a first decimation number of communications resources in said sequence and repeating this process on the remaining communications resources in said sequence of each channel in their remaining order until all of said communications resources in each channel are used to define said second set of frequency hopping communications channels.

4. The multiple access communications system as defined in claim 2 in which each of said hopping communications channels in said first set is defined by a unique sequence of said R communications resources and said first decimated transformation is performed on each of said hopping communications channels in said first set by selecting communications resources from each of said hopping communications channels in said first set in their sequential order skipping a first decimation number of communications resources in said sequence and repeating this process on the remaining communications resources in said sequence of each channel in their remaining order until all of said communications resources resources in each channel are used to define said second set of frequency hopping communications channels;

and

said second decimated transformation is performed on each of said hopping communications channels in said first set by selecting communications resources from each of said hopping communications channels in said first set in their sequential order skipping a second decimation number of communications resources in said sequence and repeating this process on the remaining communications resources in said sequence of each channel in their remaining order until all of said communications resources in each channel are used to define said third set of frequency hopping communications channels.

5. In a hopping multiple access communications system in which a set of R communications resources are used to provide hopping communications channels in said system, said system including:

a plurality of adjacent communications sites associated with said communications system; and

a central base communications station which uses said R communications resources for defining a first set of 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 hopping communications channels employ the same one of said R communications resources at the same time; and

which also uses said R communications resources for defining a second set of 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 hopping communications channels employ the same one of said R communications resources at the same time, wherein said second set of hopping communications channels is further defined as a first decimated transformation of each of said hopping communications channels in said first set.

6. In a hopping multiple access communications system as definded in claim 5 in which said central base communications station also uses said R communications resources for defining a third set of hopping communications channels associated with a third of said plurality of adjacent communications sites in which no two of said channels in said third set of hopping communications channels employ the same one of said R communications resources at the same time, wherein said third set of hopping communications channels is further defined as a second decimated transformation of each of said hopping communications channels in said first set.

7. In the multiple access hopping communications system as defined in claim 5, said system also including:

means for selectively encoding digital information signals on ones of said 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.

8. In the multiple access hopping communications system as defined in claim 5 also including:

decoding means for decoding said digital information signals which includes the use of soft decision making and side information.

9. In the multiple access hopping communications system as defined in claim 8 said system further comprising:

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 subscriber.

10. In the multiple access hopping communications system as defined in claims 5 said system further comprising:

means for performing a conference call between a plurality of subscribers in a site by causing each of said subscribers to employ the same channel.