CONTROLLING POWER IN A SPREAD SPECTRUM SYSTEM

• US 20100195553A1
• Filed: 03/31/2010
• Published: 08/05/2010
• Est. Priority Date: 03/18/2008
• Status: Abandoned Application

• Current Assignee: On-Ramp Wireless Incorporated
• Original Assignee: On-Ramp Wireless Incorporated
• Inventors: Myers, Theodore J.
• Application Number:
  US12/751,724
• Publication Number:
  US 20100195553A1
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H03J 7/02 Automatic frequency control H03J7/18 takes precedence
• CPC Class Codes: H04B 1/7073 Synchronisation aspects
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04L 2027/0095 in a preamble or similar structure
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission
• CPC Class Codes: H04W 52/10 Open loop power control

Abstract

A technique and system is disclosed for controlling power in a spread spectrum system. A fast slot of a frame is received where the frame is divided into a number of fast slots. The received power is measured on the fast slot. A second fast slot is transmitted at a second time with a transmit power setting and a variable spreading factor. The transmit power setting and the variable spreading factor is adjusted based on the received power. The variable spreading factor affects the total number of fast slots that are transmitted.

Claims

1. A method for power control in a half-duplex, multiple access spread spectrum communication interface comprising:

receiving a first fast slot of a first frame at a first time at a receiver, wherein the frame is divided into a plurality of fast slots;

measuring a first received power based on receiving the first fast slot;

transmitting a second fast slot of a second frame at a second time at a power setting at a transmitter

wherein the second frame is divided into a second plurality of fast slots,

wherein a number of fast slots in the second plurality of fast slots is determined in part from a variable spreading factor,

wherein the power setting is determined in part from the first received power, and

wherein the variable spreading factor is determined in part from the first received power.

2. The method of claim 1, wherein the second frame is spread using a PN code that also spreads a transmission by a second transmitter, and wherein the receiver and the transmitter are on a node.

3. The method of claim 1, wherein the second time is less than or equal to 2.048 milliseconds after the second time.

4. The method of claim 1, wherein each fast slot of the plurality of fast slots is smaller than a symbol.

5. The method of claim 1, wherein each fast slot of the plurality of fast slots contains a plurality of symbols.

6. The method of claim 1, wherein the second time comprises a random time offset.

7. The method of claim 1, wherein the first time comprises a random time offset.

8. The method of claim 1, wherein the first frame and the second frame are modulated using 2-ary modulation.

9. The method of claim 1, further comprising aborting a prior transmission after measuring the received power.

10. The method of claim 9, wherein the second frame is a repeat of the prior transmission.

11. The method of claim 1, wherein a number of fast slots in the second plurality of fast slots is determined in part from a constant frame size.

12. The method of claim 1, wherein at least a portion of the second fast slot overlaps at least a portion of a third fast slot in a slot which is transmitted by a second transmitter such that the second fast slot and the third fast slot can be received.

13. A node capable of controlling transmit power in a half-duplex, multiple access spread spectrum communication system comprising:

a receiver configured to receive a first fast slot of a first frame at a first time, wherein the first frame is divided into a first plurality of fast slots and to measure a first received power based on receiving the first fast slot;

a transmitter configured to transmit a second fast slot of a second frame at a second time at a power setting wherein the second frame is divided into a second plurality of fast slots, wherein a number of fast slots in the second plurality of fast slots is determined in part from a variable spreading factor;

a processor configured to adjust the power setting as determined in part from the first received power and to adjust the variable spreading factor as determined in part from the first received power.

14. The node of claim 13, wherein the second frame is spread using a PN code that also spreads a transmission by a second transmitter.

15. The node of claim 13, wherein the second time is less than or equal to 2.048 after the second time.

16. The node of claim 13, wherein each fast slot of the plurality of fast slots is smaller than a symbol.

17. The node of claim 13, wherein the second time comprises a random time offset.

18. The node of claim 13, wherein the first frame and the second frame are modulated using 2-ary modulation.

19. The node of claim 13, wherein the processor is further configured to abort a prior transmission after the first received power is measured.

20. A computer-readable medium having computer-readable instructions stored thereon that, upon execution by a processor, cause a node to:

receive a first fast slot of a frame at a first time at a receiver, wherein the frame is divided into a first plurality of fast slots;

measure a first received power based on receiving the first fast slot;

adjust a power setting as determined in part from the first received power;

adjust a variable spreading factor as determined in part from the first received power; and

transmit a second fast slot of a second frame at a second time at the power setting wherein the second frame is divided into a second plurality of fast slots and wherein a number of fast slots in the second plurality of fast slots is determined in part from the variable spreading factor.