Method and apparatus for an adaptive filter architecture

• US 9,294,144 B2
• Filed: 01/31/2014
• Issued: 03/22/2016
• Est. Priority Date: 11/11/2008
• Status: Active Grant

• Current Assignee: ISCO International Inc.
• Original Assignee: ISCO International Inc.
• Inventors: Abdelmonem, Amr, Cordone, Sean S
• Primary Examiner(s): TAYONG, HELENE E
• Application Number:
  US14/169,560
• Publication Number:
  US 20140162672A1
• Time in Patent Office: 781 Days
• Field of Search: 375/224
• 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 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7093 Matched filter type
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 17/318 Received signal strength
• 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 2001/1072 by tuning the receiver frequency
• CPC Class Codes: H04J 11/0023 Interference mitigation or co-ordination direct sequence spread spectrum [DSSS] systems H04B1/7097; frequency hopping H04B1/713; allocation criteria for ingress interference avoidance H04L5/0062; frequency allocation criteria for requirements on out-of-channel emissions H04L5/0066; arrangements for removing intersymbol interference or baseband equalisers H04L25/03006; peak power aspects in multicarrier modulation H04L27/2614; power management H04W52/00; traffic scheduling H04W72/54, H04W72/541
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

A system that incorporates teachings of the subject disclosure may include, for example, a method for identifying a spectral region in a radio frequency spectrum, determining a signal strength of the spectral region, determining a correlation factor by correlating the signal strength of the spectral region, detecting according to the correlation factor interference in the spectral region, generating coefficient data to substantially suppress the interference in the spectral region, configuring a filter according to the coefficient data to substantially suppress the interference in the spectral region and produce a digital filtered signal, and transmitting the digital filtered signal to a base station. Other embodiments are disclosed.

Claims

1. A method comprising:

identifying, by a system including a processor, a spectral region in a radio frequency spectrum independent of there being interference in the spectral region;

determining, by the system, a signal strength of the spectral region;

determining, by the system, a correlation factor by correlating the signal strength of the spectral region, wherein the determining of the correlation factor comprises determining correlation factors for a group of higher signal strengths without determining correlation factors for a group of lower signal strengths;

detecting, by the system according to the correlation factor, interference in the spectral region;

generating, by the system, coefficient data that corresponds to a bandpass frequency; and

configuring, by the system, a filter according to the coefficient data to substantially suppress the interference in the spectral region and to produce a digital filtered signal, wherein the configuring of the filter includes activating at least one target filter of a group of target filters, and wherein the group of target filters includes at least one infinite impulse response filter or finite impulse response filter.

2. The method of claim 1, comprising formatting, by the system, the digital filtered signal for transmission according to a Gigabit Ethernet protocol, an Open Base Station Architecture Initiative (OBSAI) protocol, or a Common Public Radio Interface (CPRI) protocol.

3. The method of claim 1, comprising transmitting, by the system, the digital filtered signal to a base station.

4. The method of claim 1, comprising formatting, by the system, the digital filtered signal according to a Gigabit Ethernet protocol.

5. The method of claim 1, comprising formatting, by the system, the digital filtered signal according to an Open Base Station Architecture Initiative (OBSAI) protocol.

6. The method of claim 1, comprising formatting, by the system, the digital filtered signal according to a Common Public Radio Interface (CPRI) protocol.

7. The method of claim 1, wherein the system is located in a base station.

8. A method, comprising:

selecting, by a system including a processor, an available frequency band for engaging in communications independent of there being interference in the available frequency band;

determining, by the system, a signal strength for each of a plurality of narrowband channels in the available frequency band;

determining, by the system, a correlation factor for at least a portion of the plurality of narrowband channels based on correlating of the signal strength, wherein the determining of the correlation factor comprises determining correlation factors for a group of higher signal strengths without determining correlation factors for a group of lower signal strengths;

identifying, by the system from the correlation factor, narrowband interference in a narrowband channel of the plurality of narrowband channels;

generating, by the system, tuning coefficient data based on the narrowband interference; and

configuring, by the system, a filter according to the tuning coefficient data to substantially suppress the narrowband interference in the narrowband channel and to produce a digital filtered signal.

9. The method of claim 8, comprising transmitting, by the system, the digital filtered signal to a base station.

10. The method of claim 9, wherein the system is located in a mobile device that is communicatively coupled to the base station.

11. The method of claim 8, wherein the system is located in a cellular base station.

12. The method of claim 8, comprising formatting, by the system, the digital filtered signal for transmission according to one of a Gigabit Ethernet protocol, an Open Base Station Architecture Initiative (OBSAI) protocol or a Common Public Radio Interface (CPRI) protocol.

13. The method of claim 8, wherein the configuring of the filter comprises tuning the filter to a filter frequency and a filter bandwidth according to the tuning coefficient data, wherein the filter comprises a plurality of filter elements that are arranged in parallel or in a cascaded configuration.

14. The method of claim 8, wherein the determining of the correlation factor comprises repeating a determination of the signal strength for each of the plurality of narrowband channels in the available frequency band.

15. A system, comprising:

a filter apparatus; and

a circuit coupled to the filter apparatus, wherein execution of instructions by the circuit causes the circuit to perform operations comprising;

selecting portions of a spectral region for engaging in a communication session independent of there being interference in the portions of the spectral region;

determining a signal strength for a plurality of channels corresponding to the portions of the spectral region;

determining a correlation factor by a correlation of the signal strength;

identifying from the correlation factor a channel of the plurality of channels experiencing interference;

generating coefficient data based on the interference; and

configuring the filter apparatus by tuning the filter apparatus to a filter frequency and a filter bandwidth according to the coefficient data to substantially suppress the interference and to produce a digital filtered signal,

wherein the determining of the correlation factor comprises determining correlation factors for a group of higher signal strengths without determining correlation factors for a group of lower signal strengths.

16. The system of claim 15, wherein the system is located in a cellular base station.

17. The system of claim 15, wherein the filter apparatus comprises a plurality of filter elements.

18. The system of claim 17, wherein the plurality of filter elements are arranged in a parallel configuration.

19. The system of claim 17, wherein the plurality of filter elements are arranged in a cascaded configuration.

20. The system of claim 15, wherein the system is located in a mobile device that is communicatively coupled to a cellular base station, and wherein the operations further comprise transmitting the digital filtered signal to the cellular base station.