Systems and methods for linearized-mixer out-of-band interference mitigation

• US 10,666,305 B2
• Filed: 07/22/2019
• Issued: 05/26/2020
• Est. Priority Date: 12/16/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Kumu Networks, Inc.
• Inventors: Choi, Jung-Il, Jain, Mayank, Hahn, Christian
• Primary Examiner(s): Wong, Linda
• Application Number:
  US16/518,576
• Publication Number:
  US 20190372610A1
• Time in Patent Office: 309 Days
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• 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 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 2001/0491 with frequency synthesizers, frequency converters or modulators
• CPC Class Codes: H04B 2001/1045 Adjacent-channel interference
• CPC Class Codes: H04B 2001/1072 by tuning the receiver frequency

Abstract

A system for linearized-mixer interference mitigation includes first and second linearized frequency downconverters; a sampling analog interference filtering system that, in order to remove interference in the transmit band, filters the sampled BB transmit signal to generate a cleaned BB transmit signal; an analog interference canceller that transforms the cleaned BB transmit signal to a BB interference cancellation signal; and a first signal coupler that combines the BB interference cancellation signal and the BB receive signal in order to remove a first portion of receive-band interference.

Claims

1. A system for linearized-mixer interference mitigation, comprising:

first and second linearized frequency downconverters;

wherein the first linearized frequency downconverter downconverts a sampled radio-frequency (RF) transmit signal to a baseband (BB) transmit signal having a first BB frequency;

wherein the second linearized frequency downconverter downconverts a sampled RF receive signal to a BB receive signal having a second BB frequency;

wherein each of the first and second linearized frequency downconverters comprises;

a primary mixer that generates a primary-mixer-output signal from a first local oscillator (LO) signal and an input signal;

a distortion-source mixer that generates a distortion-source-output signal from a second LO signal and the input signal; and

an output signal coupler that generates an output signal by combining the primary-mixer-output signal and the distortion-source output signal, resulting in reduced non-linear distortion;

a sampling analog interference filtering system that, in order to remove interference in the transmit band, filters the sampled BB transmit signal to generate a cleaned BB transmit signal;

a first analog-to-digital converter that converts the cleaned BB transmit signal to a digital transmit signal;

a second analog-to-digital converter that converts the BB receive signal to a digital receive signal; and

a digital interference canceller that transforms the digital transmit signal to a digital interference cancellation signal;

wherein;

the digital receive signal and the digital interference cancellation signal are combined in order to remove a first portion of receive-band interference;

the first and second BB frequencies are identical;

the sampled RF transmit signal and sampled RF receive signal have non-identical center frequencies;

each of the first and second linearized frequency downconverters further comprises an LO signal coupler that splits an input LO signal into the first and second LO signals;

the primary-mixer-output signal comprises a first-order primary-mixer-output signal component and a higher-order primary-mixer-output signal component;

the primary-mixer-output signal is characterized by a first signal power ratio of the higher-order primary-mixer-output signal component to the first-order primary-mixer-output signal component;

the distortion-source-mixer-output signal comprises a first-order distortion-mixer-output signal component and a higher-order distortion-mixer-output signal component;

the distortion-mixer-output signal is characterized by a second signal power ratio of the higher-order distortion-mixer-output signal component to the first-order distortion-mixer-output signal component; and

the second signal power ratio is greater than the first signal power ratio.

2. The system of claim 1, wherein the combination of the primary-mixer-output signal and the distortion-source output signal comprises a first-order output signal component and a higher-order output signal component;

wherein the output signal is characterized by a third signal power ratio of the higher-order output signal component to the first-order output signal component;

wherein the third signal power ratio is lesser than the first signal power ratio and lesser than the second signal power ratio.

3. The system of claim 2, further comprising a transmit analog canceller that transforms, according to a first configuration state, the sampled RF transmit signal to a first RF interference cancellation signal;

and a first receive coupler, that combines, in order to remove a first portion of interference in the transmit band and prior to frequency downconversion, the first RF interference cancellation signal and the RF receive signal to remove a second portion of receive-band interference.

4. The system of claim 3, wherein the transmit analog canceller comprises a signal divider, a set of scalers and delayers, and a signal combiner.

5. The system of claim 1, further comprising a transmit analog canceller that transforms, according to a first configuration state, the sampled RF transmit signal to a first RF interference cancellation signal;

and a first receive coupler, that combines, in order to remove a first portion of interference in the transmit band and prior to frequency downconversion, the first RF interference cancellation signal and the RF receive signal to remove a second portion of receive-band interference.

6. The system of claim 5, wherein the transmit analog canceller comprises a signal divider, a set of scalers and delayers, and a signal combiner.

7. A system for linearized-mixer interference mitigation comprising:

first and second linearized frequency downconverters;

wherein the first linearized frequency downconverter downconverts a sampled radio-frequency (RF) transmit signal to a baseband (BB) transmit signal having a first BB frequency;

wherein the second linearized frequency downconverter downconverts a sampled RF receive signal to a BB receive signal having a second BB frequency;

wherein each of the first and second linearized frequency downconverters comprises;

a primary mixer that generates a primary-mixer-output signal from a first local oscillator (LO) signal and an input signal;

a distortion-source mixer that generates a distortion-source-output signal from a second LO signal and the input signal; and

an output signal coupler that generates an output signal by combining the primary-mixer-output signal and the distortion-source output signal, resulting in reduced non-linear distortion;

a sampling analog interference filtering system that, in order to remove interference in the transmit band, filters the sampled BB transmit signal to generate a cleaned BB transmit signal;

an analog interference canceller that transforms the cleaned BB transmit signal to a BB interference cancellation signal; and

a first signal coupler that combines the BB interference cancellation signal and the BB receive signal in order to remove a first portion of receive-band interference;

wherein;

the first and second BB frequencies are identical;

the sampled RF transmit signal and sampled RF receive signal have non-identical center frequencies;

each of the first and second linearized frequency downconverters further comprises an LO signal coupler that splits an input LO signal into the first and second LO signals;

the primary-mixer-output signal comprises a first-order primary-mixer-output signal component and a higher-order primary-mixer-output signal component;

the primary-mixer-output signal is characterized by a first signal power ratio of the higher-order primary-mixer-output signal component to the first-order primary-mixer-output signal component;

the distortion-source-mixer-output signal comprises a first-order distortion-mixer-output signal component and a higher-order distortion-mixer-output signal component;

the distortion-mixer-output signal is characterized by a second signal power ratio of the higher-order distortion-mixer-output signal component to the first-order distortion-mixer-output signal component; and

the second signal power ratio is greater than the first signal power ratio.

8. The system of claim 7, wherein the combination of the primary-mixer-output signal and the distortion-source output signal comprises a first-order output signal component and a higher-order output signal component;

wherein the output signal is characterized by a third signal power ratio of the higher-order output signal component to the first-order output signal component;

wherein the third signal power ratio is lesser than the first signal power ratio and lesser than the second signal power ratio.

9. The system of claim 8, further comprising a transmit analog canceller that transforms, according to a first configuration state, the sampled RF transmit signal to a first RF interference cancellation signal;

and a first receive coupler, that combines, in order to remove a first portion of interference in the transmit band and prior to frequency downconversion, the first RF interference cancellation signal and the RF receive signal to remove a second portion of receive-band interference.

10. The system of claim 9, wherein the transmit analog canceller comprises a signal divider, a set of scalers and delayers, and a signal combiner.

11. The system of claim 7, further comprising a transmit analog canceller that transforms, according to a first configuration state, the sampled RF transmit signal to a first RF interference cancellation signal;

and a first receive coupler, that combines, in order to remove a first portion of interference in the transmit band and prior to frequency downconversion, the first RF interference cancellation signal and the RF receive signal to remove a second portion of receive-band interference.

12. The system of claim 11, wherein the transmit analog canceller comprises a signal divider, a set of scalers and delayers, and a signal combiner.