Method and apparatus for mitigating signal interference in a feedback system

• US 9,369,909 B2
• Filed: 04/21/2015
• Issued: 06/14/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: ISCO International Inc.
• Original Assignee: ISCO International Inc.
• Inventors: Abdelmonem, Amr, Galeev, Mikhail, Cordone, Sean S., Wong, Howard
• Primary Examiner(s): LEE, SIU M
• Application Number:
  US14/692,246
• Publication Number:
  US 20150229352A1
• Time in Patent Office: 420 Days
• Field of Search: 375/316, 375/346, 375/349, 375/347, 375/259, 375/285, 375/229, 375/232, 375/233
• US Class Current: 1/1
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H
• CPC Class Codes: H04B 1/709 Correlator structure
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 17/00 Monitoring; Testing of line transmission systems H04B3/46; arrangements for monitoring or testing transmission systems employing electromagnetic waves other than radio waves H04B10/07
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 17/373 Predicting channel quality or other radio frequency [RF] parameters
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04B 2201/709745 Iterative interference mitigation schemes
• CPC Class Codes: H04B 7/2634 for channel frequency control
• CPC Class Codes: H04J 11/0066 of narrowband interference narrowband interference reduction H04B1/1036
• CPC Class Codes: H04L 41/069 using logs of notifications; Post-processing of notifications
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0026 Division using four or more dimensions
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/006 : Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0073 : Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 16/28 : using beam steering
• CPC Class Codes: H04W 24/02 : Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/08 : Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 24/10 : Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/0236 : radio quality, e.g. interference, losses or delay
• CPC Class Codes: H04W 28/04 : Error control
• CPC Class Codes: H04W 4/02 : Services making use of location information
• CPC Class Codes: H04W 4/023 : using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/029 : Location-based management or tracking services
• CPC Class Codes: H04W 40/16 : based on interference
• CPC Class Codes: H04W 52/04 : TPC
• CPC Class Codes: H04W 52/14 : Separate analysis of uplink or downlink
• CPC Class Codes: H04W 52/243 : taking into account interferences
• CPC Class Codes: H04W 64/00 : Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 : with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 72/0446 : Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/52 : based on load
• CPC Class Codes: H04W 72/54 : based on quality criteria
• CPC Class Codes: H04W 72/541 : using the level of interference
• CPC Class Codes: H04W 72/542 : using measured or perceived quality

Abstract

A system that incorporates the subject disclosure may include, for example, a process that includes adjusting a filter in electrical communication between an input terminal and a demodulator. The filter is applied to an information bearing signal, e.g., to mitigate interference, received at the input terminal, resulting in a filtered signal. An error signal is received, indicative of errors detected within information obtained by demodulation of a modulated carrier of the filtered signal. A modified filter state is determined in response to the error signal and the filter is adjusted according to the modified filter state, e.g., to improve mitigation of the interference. Other embodiments are disclosed.

Claims

1. A method, comprising:

measuring, by a system comprising a processor, a plurality of power levels associated with a first plurality of frequency segments over a first radio frequency spectrum of a first wireless communication system;

calculating, by the system, a first plurality of average power levels for the first plurality of frequency segments;

averaging, by the system, the first plurality of average power levels to determine a baseline average power level for the first radio frequency spectrum;

determining, by the system, interference within a frequency spectrum of an information bearing signal received at an input terminal according to a threshold for detecting signal interference in the first plurality of frequency segments, wherein the threshold for detecting signal interference is based on the baseline average power level;

determining, by the system, a mitigation state responsive to the determining of the interference;

adjusting, by the system, a system parameter for a first mitigation of the interference, resulting in an pre-adjusted system parameter;

receiving, by the system, a first error signal indicative of errors corrected within information obtained by demodulation of a signal received according to the pre-adjusted system parameter; and

adjusting, by the system, the pre-adjusted system parameter for a second mitigation of the interference according to the first error signal.

2. The method of claim 1, further comprising determining, by the system, a modified mitigation state responsive to the first error signal, wherein the adjusting of the pre-adjusted system parameter is based on the modified mitigation state.

3. The method of claim 1, further comprising eliminating, by the system, a highest average power level from the first plurality of average power levels prior to the step of averaging the first plurality of average power levels.

4. The method of claim 1, wherein the plurality of power levels are measured over a plurality of time cycles.

5. The method of claim 1, wherein the information bearing signal comprises a modulated carrier waveform, and wherein the first error signal indicates errors corrected within information obtained by demodulation of the modulated carrier waveform of the signal.

6. The method of claim 5, wherein the demodulation of the modulated carrier waveform produces a structured sequence comprising redundant bits usable for detection of errors within the structured sequence.

7. The method of claim 6, wherein the first error signal is indicative of errors detected within the structured sequence.

8. The method of claim 6, wherein the redundant bits of the structured sequence are usable to correct errors within the structured sequence.

9. The method of claim 1, wherein the mitigation state comprises a filter state of a filter provided between the input terminal and a demodulator and the pre-adjusted system parameter comprises a pre-adjusted filter adjusted according to the filter state.

10. The method of claim 9, wherein the filter comprises a transfer function to reject a portion of interference, the adjusting of the filter comprising one of adjusting the transfer function to reject a greater portion of the interference or adjusting the transfer function to reject a lesser portion of the interference.

11. The method of claim 10, wherein the adjusting of the transfer function comprises adjusting of one of a filter width, a filter depth, a filter shape, or a combination thereof.

12. The method of claim 1, further comprising:

receiving, by the system, a second error signal indicative of errors detected within information obtained by demodulation of the signal;

determining, by the system, a re-modified mitigation state in response to one of the second error signal or the first and second error signals; and

adjusting, by the system, the system parameter according to the re-modified mitigation state.

13. A device, comprising:

a processor; and

a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising;

measuring average power levels for frequency segments over a radio frequency spectrum of a wireless communication system;

determining a baseline average power level for the radio frequency spectrum according to the average power levels for the frequency segments of the radio frequency spectrum;

determining a threshold from the baseline average power level for detecting signal interference in the frequency segments of the radio frequency spectrum of the wireless communication system;

determining a filter state to mitigate the signal interference, wherein the filter state is determined based on the signal interference that is detected via the threshold;

adjusting a filter according to the filter state, for filtering an information bearing signal that is received at an input terminal, resulting in a filtered signal;

receiving a first error signal indicative of errors corrected within information obtained from the filtered signal; and

adjusting the filter based on the first error signal.

14. The device of claim 13, wherein the operations further comprise:

determining a modified filter state in response to the first error signal; and

adjusting the filter according to the modified filter state.

15. The device of claim 13, wherein the filter is provided between an input terminal and a demodulator, wherein the information bearing signal comprises a modulated carrier, and wherein the information obtained from the information bearing signal by demodulation of the modulated carrier.

16. The device of claim 15, wherein demodulation of the modulated carrier produces a structured sequence comprising redundant bits usable for detection of errors within the structured sequence.

17. The device of claim 16, wherein the first error signal is indicative of errors detected within the structured sequence.

18. The device of claim 16, wherein the redundant bits of the structured sequence are usable to correct errors within the structured sequence.

19. A machine-readable storage device comprising instructions that when executed by a processor, cause the processor to perform operations comprising:

measuring average power levels for frequency segments over a radio frequency spectrum of a wireless communication system;

determining a baseline average power level for the radio frequency spectrum according to the average power levels for the frequency segments of the radio frequency spectrum;

determining a threshold from the baseline average power level for detecting signal interference in the frequency segments of the radio frequency spectrum of the wireless communication system;

adjusting a filter in electrical communication between an input terminal and a demodulator to filter an information bearing signal received at the input terminal, resulting in a filtered signal, wherein the adjusting of the filter is based on the signal interference that is detected;

adjusting a filter according to a filter state, for filtering an information bearing signal that is received at the input terminal, resulting in a filtered signal;

receiving a first error signal indicative of errors corrected within information obtained from the filtered signal; and

adjusting the filter based on the first error signal.

20. The machine-readable storage device of claim 19, wherein the operations further comprise eliminating a highest average power level from a plurality of average power levels for the frequency segments prior to the step of determining the baseline average power level, wherein the average power levels are measured over a plurality of time cycles.