RSSI measurement mechanism in the presence of pulsed jammers

• US 8,520,721 B2
• Filed: 05/14/2012
• Issued: 08/27/2013
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: Ingenu Inc.
• Original Assignee: On-Ramp Wireless Incorporated
• Inventors: Myers, Theodore J., Boesel, Robert W.
• Primary Examiner(s): Burd, Kevin M
• Application Number:
  US13/471,000
• Publication Number:
  US 20120224549A1
• Time in Patent Office: 470 Days
• Field of Search: 375/130, 375/140, 375/147, 375/150
• US Class Current: 375/150
• CPC Class Codes: H03J 7/02 Automatic frequency control H03J7/18 takes precedence
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04J 13/0029 Gold
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012
• CPC Class Codes: H04L 1/0046 Code rate detection or code type detection H04L1/0038 takes precedence; detection of the data rate H04L25/0262; for packet format H04L1/0091
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 2027/0065 Frequency error detectors H04L2027/0067 takes precedence
• CPC Class Codes: H04L 27/233 using non-coherent demodulation
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal

Abstract

This disclosure relates to method, device and system for controlling power in a communication system. A plurality of power levels is measured from a received signal that includes a pulsed noise source. The received signal is correlated with a known sequence creating a correlation metric. A signal power is determined based on the correlation metric and the plurality of power levels. An uplink signal is transmitted at a transmit power that is based on the signal power.

Claims

1. A method of controlling power in a communication system, the method comprising:

correlating a received signal, received at a receiver, with a known sequence to determine a correlation metric over a correlating period of time;

measuring a plurality of sampled power levels from the received signal at a frequency whose period is less than the correlating period of time, wherein the received signal comprises a pulsed noise signal, and wherein the pulsed noise signal interferes with the received signal for a portion of the period of time;

determining a high-energy metric based upon an average of the plurality of sampled power levels;

determining a signal power using the correlation metric and the high-energy metric, wherein at least a portion of the pulsed noise signal power is excluded from the signal power based upon at least the plurality of sampled power levels; and

transmitting an uplink signal at a transmit power at a transmitter wherein the transmit power is based in part on the determined signal power, wherein the uplink signal is transmitted at a first time based on a slot start time and a first random timing offset, wherein the uplink signal is transmitted while at least a portion of a second signal is transmitted from a second node such that both the uplink signal and the second signal are received, and wherein the second signal is transmitted at a second time based on the slot start time and a second random timing offset.

2. The method of claim 1, wherein the correlation metric is determined in part by computing an average of a plurality of despread symbols, wherein a despread symbol of the plurality of despread symbols is computed in part from correlating the received signal with the known sequence.

3. The method of claim 2, wherein the plurality of despread symbols comprises sixteen despread symbols.

4. The method of claim 1, wherein the correlation metric is determined in part from an empirical mapping of the correlated received signal.

5. The method of claim 1, wherein the known sequence is a gold code.

6. The method of claim 1, wherein the plurality of sampled power levels are measured during a second period of time that overlaps with the correlating period of time used.

7. The method of claim 1, wherein the signal power excluding power of the pulsed noise signal is calculated as CM*[1/AVG(1/SQRT(P_i))]² where CM is the correlation metric and P_i is each of the plurality of sampled power levels.

8. The method of claim 1, wherein the received signal comprises a broadcast channel.

9. The method of claim 1, further comprising calculating a node interference based in part on the signal power, and transmitting the node interference to an access point.

10. A node comprising:

a processor;

a receiver operatively coupled to the processor and configured to;

correlate a received signal with a known sequence to determine a correlation metric over a correlating period of time;

measure a plurality of sampled power levels from the received signal at a frequency whose period is less than the correlating period of time, wherein the received signal comprises a pulsed noise signaand wherein the pulsed noise signal interferes with the received signal for a portion of the period of time; and

determine a high-energy metric based upon an average of the plurality of sampled power levels;

determine a signal power using the correlation metric and the high-energy metric, wherein at least a portion of the pulsed noise signal power is excluded from the signal power based upon at least the plurality of sampled power levels; and

a transmitter operatively coupled to the processor and configured to;

transmit a signal at a transmit power based in part on the determined signal power, wherein the signal is transmitted at a first time based on a slot start time and a first random timing offset, wherein the signal is transmitted while at least a portion of a second signal is transmitted from a second node such that both the signal and the second signal are received, and wherein the second signal is transmitted at a second time based on the slot start time and a second random timing offset.

11. The node of claim 10, wherein the correlation metric is determined in part by computing an average of a plurality of despread symbols, wherein each despread symbol of the plurality of despread symbols is computed in part from correlating the received signal with the known sequence.

12. The node of claim 10, wherein the known sequence is a gold code.

13. The node of claim 10, wherein the plurality of sampled power levels are measured during a second period of time that overlaps with the correlating period of time.

14. The node of claim 10, wherein the received signal comprises a broadcast channel.

15. A system comprising:

an access point comprising;

a downlink transmitter configured to transmit a downlink signal; and

a node comprising;

a processor;

a receiver operatively coupled to the processor and configured to;

correlate a received signal with a known sequence to determine a correlation metric over a correlating period of time;

measure a plurality of sampled power levels from the received signal at a frequency whose period is less than the correlating period of time, wherein the received signal comprises a pulsed noise signal, and wherein the pulsed noise signal interferes with the received signal for a portion of the period of time; and

determine a high-energy metric based upon an average of the plurality of sampled power levels;

determine a signal power using the correlation metric and the high-energy metric, wherein at least a portion of the pulsed noise signal power is excluded from the signal power based upon at least the plurality of sampled power levels; and

a transmitter operatively coupled to the processor and configured to;

transmit a signal at a transmit power wherein the transmit power is based in part on the determined signal power, wherein the signal is transmitted at a first time based on a slot start time and a first random timing offset, wherein the signal is transmitted while at least a portion of a second signal is transmitted from a second node such that both the signal and the second signal are received, and wherein the second signal is transmitted at a second time based on the slot start time and a second random timing offset.

16. The system of claim 15, wherein the correlation metric is determined in part by computing an average of a plurality of despread symbols, wherein each despread symbol of the plurality of despread symbols is computed in part from correlating the received signal with the known sequence.

17. The system of claim 15, wherein the known sequence is a gold code.

18. The system of claim 15, wherein the plurality of sampled power levels are measured during a second period of time that overlaps with the correlating period of time.

19. The system of claim 15, wherein the received signal comprises a broadcast channel.