Peer-peer frequency hopping spread spectrum wireless system

• US 5,887,022 A
• Filed: 06/12/1996
• Issued: 03/23/1999
• Est. Priority Date: 06/12/1996
• Status: Expired due to Term

• Current Assignee: Telecommunications Research Laboratories
• Original Assignee: Telecommunications Research Laboratories
• Inventors: Lee, Wilson, Fattouche, Michael
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Bayard, Emmanuel
• Application Number:
  US08/662,155
• Time in Patent Office: 1,014 Days
• Field of Search: 370/522, 370/524, 370/280, 370/330, 375/202, 375/200
• US Class Current: 375/132
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

A peer--peer frequency hopping spread spectrum wireless system allows the implementation of full duplex voice/data communications in a single hop peer--peer wireless system. The system uses frequency hopping spread spectrum technique. The frequency band is divided into signalling and message channels. The signalling channels use TDMA with a media access control(MAC) protocol developed for the wireless terminals to access the signalling channels. Once a wireless terminal accesses a time slot on a signalling channel, the corresponding hopping pattern on the message channel is assigned. The message channels use frequency hopping. The hopping patterns of the message channel are chosen such that there is no co-channel interference and minimum adjacent channel interference in the system. Either analog or digital modulation schemes can be used. Synchronization of a transmitter-receiver pair (user-pair) and among user-pairs are achieved through the use of the signalling channels.

Claims

1. A method of radio communication between at least two wireless terminals over an allocated frequency band, in which the allocated frequency band is divided into a signalling channel and a message channel, the message channel is divided into frequency slots and the signalling channel is divided into time slots, the method comprising the steps of:

initiating a call by a wireless terminal accessing an idle time slot in the signalling channel;

the wireless terminal subsequently transmitting message data in the message channel using a distinct frequency hopping pattern corresponding to the time slot accessed by the wireless terminal;

the allocated frequency band having N frequency slots in the message channel and a set of N frequency hopping patterns being available for use by the terminal pairs, the set of N frequency hopping patterns being characterized by being selected from the group consisting of;

(A) the set A of N frequency hopping patterns defined by;

space="preserve" listing-type="tabular">______________________________________column #1 #2 #3 #4 #5 #6 #7______________________________________pattern #1 1 2 3 4 5 6. . .pattern #2 3 4 5 6 7 8. . .pattern #3 5 6 7 8 9 10. . . . . . . . . . . .pattern #N/2 N-1 N 1 2 3 4. . .pattern #(N/2+1) 2 3 N 1 N-2 N-1 N-4pattern #(N/2+2) 4 5 2 3 N 1 N-2pattern #(N/2+3) 6 7 4 5 2 3 N . . . . . . . . .pattern #N N 1 N-2 N-1 N-4 N-3 N-6______________________________________column #8 #(N-3) #(N-2) #(N-1) #N______________________________________pattern #1 N-3 N-2 N-1 N!pattern #2 N-1 N 1 2!pattern #3 1 2 3 4!pattern #N/2 N-5 N-4 N-3 N-2!pattern #(N/2+1) N-3. . . 4 5!pattern #(N/2+2) N-1. . . 6 7!pattern #(N/2+3) 1. . . 8 9! . . . . . . . . . . . .pattern #N N-5. . . 2 3!;

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and

(B) any set of N frequency hopping patterns consisting of any combination of the columns of the frequency hopping pattern defined in set A.

2. A method of radio communication between at least two wireless terminals over an allocated frequency band, in which the allocated frequency band is divided into a signalling channel and a message channel, the method comprising the steps of:

exchanging message data between the wireless terminals by transmitting and receiving message data over the message channel;

each wireless terminal periodically hopping into the signalling channel during transmission of message data to synchronize the wireless terminals to each other;

the message channel being divided into frequency slots and during transmission of message data each wireless terminal periodically hops in the message channel frequency slots;

the allocated frequency band having N frequency slots in the message channel and a set of N frequency hopping patterns being available for use by the terminal pairs, the set of N frequency hopping patterns being characterized by being selected from the group consisting of;

(A) the set A of N frequency hopping patterns defined by;

space="preserve" listing-type="tabular">______________________________________column #1 #2 #3 #4 #5 #6 #7______________________________________pattern #1 1 2 3 4 5 6. . .pattern #2 3 4 5 6 7 8. . .pattern #3 5 6 7 8 9 10. . . . . . . . . . . .pattern #N/2 N-1 N 1 2 3 4. . .pattern #(N/2+1) 2 3 N 1 N-2 N-1 N-4pattern #(N/2+2) 4 5 2 3 N 1 N-2pattern #(N/2+3) 6 7 4 5 2 3 N . . . . . . . . .pattern #N N 1 N-2 N-1 N-4 N-3 N-6______________________________________column #8 #(N-3) #(N-2) #(N-1) #N______________________________________pattern #1 N-3 N-2 N-1 N!pattern #2 N-1 N 1 2!pattern #3 1 2 3 4! . . . . . . . . . . . . . . .pattern #N/2 N-5 N-4 N-3 N-2!pattern #(N/2+1) N-3. . . 4 5!pattern #(N/2+2) N-1. . . 6 7!pattern #(N/2+3) 1. . . 8 9! . . . . . . . . . . . . . . .pattern #N N-5. . . 2 3!;

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and

(B) any set of N frequency hopping patterns consisting of any combination of the columns of the frequency hopping pattern defined in set A.

3. The method of claim 2 in which the signalling channel is divided into time slots, and the method further comprises the steps of:

a wireless terminal initiating a call by accessing an idle time slot in the signalling channel; and

the wireless terminal subsequently transmitting message data using a distinct frequency hopping pattern corresponding to the time slot accessed by the wireless terminal.

4. The method of claim 2 in which the signalling channel is divided into time slots and the method further comprising the step of:

accessing the signalling channel by each wireless terminal initially scanning the signalling channel to search for an idle time slot and;

(a) if all time slots are idle, subsequently transmitting signals in any usable time slot;

(b) if one or more but not all time slots are busy, searching for a usable time slot adjacent to a busy time slot and subsequently transmitting signals in the usable time slot; and

(c) if all time slots are busy, transmitting a busy tone to the wireless terminal or repeating the scan for an idle time slot.

5. A method of radio communication between at least two wireless terminals over an allocated frequency band, in which the allocated frequency band is divided into at least a signalling channel and a message channel, the message channel being divided into N frequency slots, the method comprising the steps of:

assigning to each wireless terminal a frequency hopping pattern selected from a set of N frequency hopping patterns that are available for use by the wireless terminals;

the wireless terminal subsequently transmitting message data using the frequency hopping pattern; and

the set of N frequency hopping patterns being characterized by being selected from the group consisting of;

(A) the set A of N frequency hopping patterns defined by;

space="preserve" listing-type="tabular">__________________________________________________________________________column #1 #2 #3 #4 #5 #6 #7 #8 #(N-3) #(N-2) #(N-1) #N__________________________________________________________________________pattern #1 1 2 3 4 5 6 . . . N-3 N-2 N-1 N!pattern #2 3 4 5 6 7 8 . . . N-1 N 1 2!pattern #3 5 6 7 8 9 10 . . . 1 2 3 4! . . . . . . . . .pattern #N/2 N-1 N 1 2 3 4 . . . N-5 N-4 N-3 N-2!pattern #(N/2 +

     1) 2 3 N 1 N-2 N-1 N-4 N-3 . . . 4 5!pattern #(N/2 +

     2) 4 5 2 3 N 1 N-2 N-1 . . . 6 7!pattern #(N/2 +

     3) 6 7 4 5 2 3 N 1 . . . 8 9! . . . . . . . . .pattern #N N 1 N-2 N-1 N-4 N-3 N-6 N-5 . . . 2 3!;

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and

(B) any set of N frequency hopping patterns consisting of any combination of the columns of the frequency hopping pattern defined in set A.

6. The method of claim 5 in which the signalling channel is divided into at least N time slots and each time slot is associated with a distinct frequency hopping pattern, the method further comprising the steps of:

assigning the frequency hopping pattern associated with a time slot to a wireless terminal when the wireless terminal accesses that time slot for signalling.

7. A method of radio communication between at least two wireless terminals over an allocated frequency band, in which the allocated frequency band is divided into a signalling channel and a message channel, the signalling channel being divided into time slots, the method comprising the steps of:

exchanging message data between the wireless terminals by transmitting and receiving message data over the message channel; and

accessing the signalling channel by each wireless terminal initially scanning the signalling channel to search for an idle time slot and;

(a) if all time slots are idle, subsequently transmitting signals in any usable time slot;

(b) if one or more but not all time slots are busy, searching for a usable time slot adjacent to a busy time slot and subsequently transmitting signals in the usable time slot; and

(c) if all time slots are busy, transmitting a busy tone to the wireless terminal or repeating the scan for an idle time slot.

8. A wireless terminal, comprising:

a radio transceiver;

a frequency synthesizer having output operatively coupled to the radio transceiver, the output of the frequency synthesizer including a signalling channel and a message channel;

a synchronizer operatively coupled to the radio transceiver for the exchange of synchronization information;

a codec operatively coupled to the radio transceiver for the exchange, coding and decoding of message information between a source of message information and the radio transceiver; and

a controller operatively coupled to the synchronizer and the frequency synthesizer for instructing the frequency synthesizer to periodically hop into the signalling channel during exchange of message information on the message channel and the synchronizer to provide synchronization information to the radio transceiver during a hop by the frequency synthesizer into the signalling channel.

9. The wireless terminal of claim 8 in which:

the controller has a memory, the message channel includes N frequency slots and the memory stores a set of N frequency hopping patterns, the set of N frequency hopping patterns being characterized by being selected from the group consisting of;

(A) the set A of N frequency hopping patterns defined by;

space="preserve" listing-type="tabular">__________________________________________________________________________column #1 #2 #3 #4 #5 #6 #7 #8 #(N-3) #(N-2) #(N-1) #N__________________________________________________________________________pattern #1 1 2 3 4 5 6 . . . N-3 N-2 N-1 N!pattern #2 3 4 5 6 7 8 . . . N-1 N 1 2!pattern #3 5 6 7 8 9 10 . . . 1 2 3 4! . . . . . . . . .pattern #N/2 N-1 N 1 2 3 4 . . . N-5 N-4 N-3 N-2!pattern #(N/2 +

     1) 2 3 N 1 N-2 N-1 N-4 N-3 . . . 4 5!pattern #(N/2 +

     2) 4 5 2 3 N 1 N-2 N-1 . . . 6 7!pattern #(N/2 +

     3) 6 7 4 5 2 3 N 1 . . . 8 9! . . . . . . . . .pattern #N N 1 N-2 N-1 N-4 N-3 N-6 N-5 . . . 2 3!;

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and

(B) any set of N frequency hopping patterns consisting of any combination of the columns of the frequency hopping pattern defined in set A.

10. A wireless terminal, comprising:

a radio transceiver;

a frequency synthesizer having output operatively coupled to the radio transceiver, the output of the frequency synthesizer including a signalling channel and a message channel, the signalling channel being divided into time slots;

a synchronizer operatively coupled to the radio transceiver for the exchange of synchronization information;

a codec operatively coupled to the radio transceiver for the exchange, coding and decoding of message information between a source of message information and the radio transceiver; and

a controller operatively coupled to the synchronizer and the frequency synthesizer for instructing the frequency synthesizer to periodically hop in the message channel according to a stored frequency hopping pattern uniquely corresponding to one of the time slots in the signalling channel.

11. The wireless terminal of claim 10 in which:

the controller has a memory, the message channel includes N frequency slots and the memory stores a set of N frequency hopping patterns, the set of N frequency hopping patterns being characterized by being selected from the group consisting of;

(A) the set A of N frequency hopping patterns defined by;

space="preserve" listing-type="tabular">__________________________________________________________________________column #1 #2 #3 #4 #5 #6 #7 #8 #(N-3) #(N-2) #(N-1) #N__________________________________________________________________________pattern #1 1 2 3 4 5 6 . . . N-3 N-2 N-1 N!pattern #2 3 4 5 6 7 8 . . . N-1 N 1 2!pattern #3 5 6 7 8 9 10 . . . 1 2 3 4! . . . . . . . . .pattern #N/2 N-1 N 1 2 3 4 . . . N-5 N-4 N-3 N-2!pattern #(N/2 +

     1) 2 3 N 1 N-2 N-1 N-4 N-3 . . . 4 5!pattern #(N/2 +

     2) 4 5 2 3 N 1 N-2 N-1 . . . 6 7!pattern #(N/2 +

     3) 6 7 4 5 2 3 N 1 . . . 8 9! . . . . . . . . .pattern #N N 1 N-2 N-1 N-4 N-3 N-6 N-5 . . . 2 3!;

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and

(B) any set of N frequency hopping patterns consisting of any combination of the columns of the frequency hopping pattern defined in set A.

12. A wireless terminal, comprising:

a radio transceiver;

a frequency synthesizer having output operatively coupled to the radio transceiver, the output of the frequency synthesizer including a signalling channel and a message channel, the signalling channel being divided into time slots;

a synchronizer operatively coupled to the radio transceiver for the exchange of synchronization information;

a codec operatively coupled to the radio transceiver for the exchange, coding and decoding of message information between a source of message information and the radio transceiver; and

a controller operatively coupled to the synchronizer and the frequency synthesizer for instructing the frequency synthesizer to scan the signalling channel to search for an idle time slot according to a search program, in which the search program contains instructions;

(a) if all time slots are idle, to cause the radio transceiver to transmit signals in any usable time slot;

(b) if one or more but not all time slots are busy, to search for a usable time slot adjacent to a busy time slot and to cause the radio transceiver to transmit signals in the usable time slot; and

(c) if all time slots are busy, to cause the wireless terminal to emit a busy tone to the wireless terminal or repeat the scan for an idle time slot.

13. A wireless terminal, comprising:

a radio transceiver;

a frequency synthesizer having output operatively coupled to the radio transceiver, the output of the frequency synthesizer including a signalling channel and a message channel, the signalling channel being divided into time slots and the message channel being divided into frequency slots;

a synchronizer operatively coupled to the radio transceiver for the exchange of synchronization information;

a codec operatively coupled to the radio transceiver for the exchange, coding and decoding of message information between a source of message information and the radio transceiver; and

a controller operatively coupled to the synchronizer and the frequency synthesizer for instructing the frequency synthesizer to periodically hop in the message channel according to a stored frequency hopping pattern characterized by being selected from the group consisting of;

(A) the set A of N frequency hopping patterns defined by;

space="preserve" listing-type="tabular">__________________________________________________________________________column #1 #2 #3 #4 #5 #6 #7 #8 #(N-3) #(N-2) #(N-1) #N__________________________________________________________________________pattern #1 1 2 3 4 5 6 . . . N-3 N-2 N-1 N!pattern #2 3 4 5 6 7 8 . . . N-1 N 1 2!pattern #3 5 6 7 8 9 10 . . . 1 2 3 4! . . . . . . . . .pattern #N/2 N-1 N 1 2 3 4 . . . N-5 N-4 N-3 N-2!pattern #(N/2 +

     1) 2 3 N 1 N-2 N-1 N-4 N-3 . . . 4 5!pattern #(N/2 +

     2) 4 5 2 3 N 1 N-2 N-1 . . . 6 7!pattern #(N/2 +

     3) 6 7 4 5 2 3 N 1 . . . 8 9! . . . . . . . . .pattern #N N 1 N-2 N-1 N-4 N-3 N-6 N-5 . . . 2 3!;

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and

(B) any set of N frequency hopping patterns consisting of any combination of the columns of the frequency hopping pattern defined in set A.