Apparatus and method for effecting synchrony in a wireless communication system

• US 6,748,040 B1
• Filed: 11/09/2000
• Issued: 06/08/2004
• Est. Priority Date: 11/09/2000
• Status: Active Grant

• Current Assignee: Humatics Corporation
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Johnson, Timothy A., Jett, Preston
• Primary Examiner(s): Tran, Khai
• Application Number:
  US09/711,026
• Time in Patent Office: 1,307 Days
• Field of Search: 375/354, 375/355, 375/356, 375/358, 375/316, 375/376
• US Class Current: 375/354
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 2001/6908 using time hopping

Abstract

An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system is disclosed. The transmitted signal is encoded according to a predetermined coding scheme and arranged in a plurality of first frames in a first succession having a first period. The apparatus comprises: (a) a timing circuit for generating a trigger signal for effecting periodic sampling of the transmitted signal at a sampling node; the trigger signal and the transmitted signal cooperate at the sampling node to generate a detection indication signal; (b) a reference signal source for generating a reference signal for the timing circuit in a plurality of second frames in a second succession having a second period; an amount by which the first period and the second period differ establishes a base offset; (c) an offset generator device; the offset generator device is coupled with the sampling node and with the timing circuit; the offset generator device receives the detection indication signal. The offset generator device determines a code offset related to elapsed time following a beginning of a respective frame of the plurality of first frames during which an expression encoded according to the predetermined coding scheme may be received. The offset generator device generates a frame offset signal by which to effect adjusting sending the trigger signal by the timing circuit from the second period to adjust synchrony with the transmitted signal. The frame offset signal involves the base offset and the code offset.

Claims

1. An apparatus for effecting synchrony in a wireless communication system;

said communication system including at least one transmitting station;

said at least one transmitting station sending a transmission signal in a plurality of first frames in a first succession having a first period;

said transmission signal being encoded according to a predetermined coding scheme;

said communication system including a receiving station for receiving said transmission signal;

said receiving station including an antenna for receiving said transmission signal;

the apparatus comprising;

(a) an oscillator device generating a receiver timing reference signal in a plurality of second frames in a second succession having a second period;

an amount by which said first period and said second period differ establishing a base offset;

(b) a timing circuit;

said timing circuit being coupled with said antenna and generating a trigger signal for effecting periodic sampling of said transmission signal at a sampling node;

said trigger signal and said transmission signals cooperating at said sampling node to generate a detection indication signal;

said timing circuit receiving said receiver timing reference signal from said oscillator device;

(c) a seeking device;

said seeking device being connected with said sampling node and receiving said detection indication signal;

said seeking device periodically imposing a stepwise timing variance to said detection indication signal to generate an incremented detection indication signal;

(d) an offset generating device coupled with said seeking device;

said offset generating device employing said incremented detection indication signal and said base offset to generate a frame offset signal;

(e) a code reconstruction device coupled with said offset generating device and with said timing circuit;

said code reconstruction device generating said predetermined coding scheme at said receiving station;

said code reconstruction device generating a code offset signal related to said predetermined coding scheme;

said timing circuit employing said receiver timing reference signal, said frame offset signal and said code offset signal to determine said trigger signal.

2. An apparatus for effecting synchrony in a wireless communication system as recited in claim 1 wherein said offset generating device further comprises a frame offset load control device for providing said frame offset at selected predetermined offset load times within selected frames of said second succession.

3. An apparatus for effecting synchrony in a wireless communication system as recited in claim 2 wherein said predetermined offset load times occur at a plurality of substantially equal intervals within said selected frames.

4. An apparatus for effecting synchrony in a wireless communication system as recited in claim 1 wherein said code reconstruction device includes a pseudorandom code generator generating a pseudorandom code signal, and includes a modulation code generator generating a modulation code signal;

said code generating device employing said pseudorandom code signal and said modulation code signal in generating said code offset signal.

5. An apparatus for effecting synchrony in a wireless communication system as recited in claim 1, 2, 3 or 4 wherein said seeking device imposes said step-wise timing variance in a first step size when the apparatus seeks to acquire synchrony with said transmission signal, and wherein said seeking device imposes said step-wise timing variance in a second step size when the apparatus seeks to track said transmission signal to maintain synchrony with said transmission signal.

6. An apparatus for effecting synchrony in a wireless communication system as recited in claim 5 wherein said first step size is larger than said second step size.

7. A method for effecting synchrony in a wireless communication system;

said communication system including at least one transmitting station;

said at least one transmitting station sending a transmission signal in a plurality of first frames in a first succession having a first period;

said transmission signal being encoded according to a predetermined coding scheme;

said communication system including at least one receiving station for receiving said transmission signal;

said receiving station including an antenna for receiving said transmission signal;

the method comprising the steps of;

(a) generating a receiver timing reference signal in a plurality of second frames in a second succession having a second period;

an amount by which said first period and said second period differ establishing a base offset;

(b) generating a trigger signal for effecting periodic sampling of said transmission signal at a sampling node;

said trigger signal and said transmission signals cooperate at said sampling node to generate a detection indication signal;

said timing circuit receiving said receiver timing reference signal from said oscillator device;

(c) periodically imposing a stepwise timing variance to said detection indication signal to generate an incremented detection indication signal;

(d) employing said incremented detection indication signal and said base offset to generate a frame offset signal;

(e) generating a code offset signal based upon said predetermined coding scheme;

(f) employing said receiver timing reference signal, said frame offset signal and said code offset signal to determine said trigger signal; and

(g) repeating steps (a) through (f) for each frame of said first succession to maintain said synchrony.

8. A method for effecting synchrony in a wireless communication as recited in claim 7 wherein step (d) further comprises:

providing said frame offset at selected predetermined offset load times within selected frames of said second succession.

9. A method for effecting synchrony in a wireless communication system as recited in claim 8 wherein said predetermined offset load times occur at a plurality of substantially equal intervals within said selected frames.

10. A method for effecting synchrony in a wireless communication system as recited in claim 7 wherein said generating a code offset signal includes employment of a pseudorandom code signal and a modulation code signal.

11. A method for effecting synchrony in a wireless communication system as recited in claim 7, 8, 9 or 10 wherein said step-wise timing variance is imposed in a first step size when the method is employed to acquire synchrony with said transmission signal, and wherein said step-wise timing variance is imposed in a second step size when the method is employed to track said transmission signal to maintain synchrony with said transmission signal.

12. A method for effecting synchrony in a wireless communication system as recited in claim 11 wherein said first step size is larger than said second step size.

13. An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system;

said transmitted signal being encoded according to a predetermined coding scheme and arranged in a plurality of first frames in a first succession having a first period;

the apparatus comprising;

(a) a timing circuit for generating a trigger signal for effecting periodic sampling of said transmitted signal at a sampling node;

said trigger signal and said transmitted signal cooperating at said sampling node to generate a detection indication signal;

(b) a reference signal source coupled with said timing circuit for generating a reference signal for said timing circuit in a plurality of second frames in a second succession having a second period;

an amount by which said first period and said second period differ establishing a base offset;

(c) an offset generator device;

said offset generator device being coupled with said sampling node and with said timing circuit;

said offset generator device receiving said detection indication signal;

said offset generator device determining a code offset related to elapsed time following a beginning of a respective frame of said plurality of first frames during which an expression encoded according to said predetermined coding scheme can be received;

said offset generator device generating a frame offset signal by which to effect adjusting sending said trigger signal by said timing circuit from said second period to adjust synchrony with said transmitted signal;

said frame offset signal involving said base offset and said code offset.

14. An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 13 wherein said offset generator device includes a frame offset load control device for effecting loading said frame offset signal at selected predetermined offset load times within selected frames of said second succession.

15. An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 14 wherein said predetermined offset load times occur at a plurality of substantially equal intervals within said selected frames.

16. An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 13, 14 or 15 wherein said offset generator device periodically imposes a step-wise timing variance to said frame offset signal to vary said synchrony.

17. An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 16 wherein said step-wise timing variance is imposed in a first step size when the apparatus seeks to acquire synchrony, and wherein said step-wise timing variance is imposed in a second step size when the apparatus seeks to track said transmitted signal to maintain synchrony.

18. An apparatus for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 17 wherein said first step size is larger than said second step size.

19. A method for effecting synchrony with a received transmitted signal in a wireless communication system;

said transmitted signal being encoded according to a predetermined coding scheme and arranged in a plurality of first frames in a first succession having a first period;

the apparatus comprising;

(a) generating a trigger signal for effecting periodic sampling of said transmitted signal at a sampling node;

said trigger signal and said transmitted signal cooperating at said sampling node to generate a detection indication signal;

(b) generating a reference signal in a plurality of second frames in a second succession having a second period;

an amount by which said first period and said second period differ establishing a base offset;

(c) determining a code offset related to elapsed time following a beginning of a respective frame of said plurality of first frames during which an expression encoded according to said predetermined coding scheme can be received;

(d) generating a frame offset signal involving said base offset and said code offset;

(e) applying said frame offset signal to adjust sending said trigger signal from said second period to adjust synchrony with said transmitted signal.

20. A method for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 19 wherein said frame offset signal is provided according to a frame offset load control device;

said frame offset load control device effecting loading said frame offset signal at selected predetermined offset load times within selected frames of said second succession.

21. A method for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 20 wherein said predetermined offset load times occur at a plurality of substantially equal intervals within said selected frames.

22. Method for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 19, 20 or 21 wherein said frame offset signal periodically includes a step-wise timing variance to vary said synchrony.

23. A method for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 22 wherein said step-wise timing variance is included in a first step size when the method seeks to acquire synchrony, and wherein said step-wise timing variance is included in a second step size when the method seeks to track said transmitted signal to maintain synchrony.

24. A method for effecting synchrony with a received transmitted signal in a wireless communication system as recited in claim 23 wherein said first step size is larger than said second step size.