Method and apparatus for in-channel interference cancellation

• US 9,385,763 B1
• Filed: 01/26/2015
• Issued: 07/05/2016
• Est. Priority Date: 01/26/2015
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Heck, Joseph P, Stengel, Robert E, Shi, Qicai, Correal, Neiyer S, Kyperountas, Spyros
• Primary Examiner(s): Sorowar, Golam
• Application Number:
  US14/605,481
• Publication Number:
  US 20160218754A1
• Time in Patent Office: 526 Days
• 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: H04J 11/0066 of narrowband interference narrowband interference reduction H04B1/1036
• CPC Class Codes: H04L 25/03821 Inter-carrier interference cancellation [ICI]

Abstract

A communication device includes a receiver that is capable of canceling in -channel interference. The receiver includes an antenna for receiving a wireless signal comprising in-channel components and an out-of-channel component, wherein the in-channel components comprise a desired component and an in-channel interference component. A first filter of the receiver filters the wireless signal by blocking at least a portion of the out-of-channel component to produce a first signal comprising the in -channel components, and at least a second filter of the receiver filters the wireless signal by blocking at least a portion of the in-channel components to produce a second signal comprising the out-of-channel component. An in-channel interference estimator of the receiver generates an in-channel interference estimation signal based on the second signal. And a combiner of the filter combines the first signal and the second signal to at least partially cancel the in-channel interference component of the first signal.

Claims

1. A method for interference cancellation in a wireless communication system, the method comprising the steps of:

receiving first, second, and third non-overlapping portions of spectrum;

using the first and the second non-overlapping portions of spectrum to estimate power amplifier coefficients used to generate the first and the second portions of spectrum;

using the power amplifier coefficients to predict interference within the third portion of spectrum;

using the predicted interference to cancel interference within the third portion of spectrum; and

wherein the step of using the first and the second non-overlapping portions of spectrum to estimate power amplifier coefficients comprises the step of using a minimum mean squared error (MMSE) criterion to find coefficients of a 3^rd term, 5^th term and 7^th by finding vector α

that minimizes;

2. The method of claim 1 wherein the first, second, and third non-overlapping portions of spectrum comprise a wideband transmission (S_LTE), an interference (S_OOBE), and a narrowband channel (NB PS), respectively.

3. The method of claim 1 further comprising the steps of:

calculating

S_LTE=S_LTE|√

{square root over (mean(S_LTE²),)} S_3rd=(|S_LTE|)²*S_LTE, S_5th=(|S_LTE|)⁴*S_LTE, S_7th=(|S_LTE|)⁶*S_LTE, S′

_3rd=Bandpass_Filter(S_3rd), S′

_5th=Bandpass_Filter(S_5th), S′

_7th=Bandpass_Filter(S_7th),

and wherein

4. An apparatus comprising:

at least one antenna receiving first, second, and third non-overlapping portions of spectrum;

a first estimator using the first and the second non-overlapping portions of spectrum to estimate power amplifier coefficients used to generate the first and the second portions of spectrum;

a second estimator using the power amplifier coefficients to predict interference within the third portion of spectrum;

interference suppression circuitry using the predicted interference to cancel interference within the third portion of spectrum,

wherein the first, second, and third non-overlapping portions of spectrum comprise a wideband transmission (S_LTE), an interference (S_OOBE) 402, and a narrowband channel (NB PS), respectively; and

wherein, the power amplifier coefficients comprise coefficients of a 3^rd term, 5^th term and 7^th term of a vector α

that minimizes