Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective
Self-interference (SI) is the key issue that prevents in-band full-duplex (IBFD) communications from being practical. Analog multi-tap adaptive filter is an efficient structure to cancel SI since it can capture the nonlinear components and noise in the transmitted signal. Analog least mean square (A...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-01-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/20/1/270 |
| _version_ | 1811300279412326400 |
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| author | Anh Tuyen Le Le Chung Tran Xiaojing Huang Yingjie Jay Guo |
| author_facet | Anh Tuyen Le Le Chung Tran Xiaojing Huang Yingjie Jay Guo |
| author_sort | Anh Tuyen Le |
| collection | DOAJ |
| description | Self-interference (SI) is the key issue that prevents in-band full-duplex (IBFD) communications from being practical. Analog multi-tap adaptive filter is an efficient structure to cancel SI since it can capture the nonlinear components and noise in the transmitted signal. Analog least mean square (ALMS) loop is a simple adaptive filter that can be implemented by purely analog means to sufficiently mitigate SI. Comprehensive analyses on the behaviors of the ALMS loop have been published in the literature. This paper proposes a practical structure and presents an implementation of the ALMS loop. By employing off-the-shelf components, a prototype of the ALMS loop including two taps is implemented for an IBFD system operating at the carrier frequency of 2.4 GHz. The prototype is firstly evaluated in a single carrier signaling IBFD system with 20 MHz and 50 MHz bandwidths, respectively. Measured results show that the ALMS loop can provide 39 dB and 33 dB of SI cancellation in the radio frequency domain for the two bandwidths, respectively. Furthermore, the impact of the roll-off factor of the pulse shaping filter on the SI cancellation level provided by the prototype is presented. Finally, the experiment with multicarrier signaling shows that the performance of the ALMS loop is the same as that in the single carrier system. These experimental results validate the theoretical analyses presented in our previous publications on the ALMS loop behaviors. |
| first_indexed | 2024-04-13T06:48:42Z |
| format | Article |
| id | doaj.art-c74be6d1484b4ef5b9670644319f20f6 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-13T06:48:42Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-c74be6d1484b4ef5b9670644319f20f62022-12-22T02:57:29ZengMDPI AGSensors1424-82202020-01-0120127010.3390/s20010270s20010270Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical PerspectiveAnh Tuyen Le0Le Chung Tran1Xiaojing Huang2Yingjie Jay Guo3School of Electrical and Data Engineering, University of Technology Sydney, Ultimo 2007, AustraliaSchool of Electrical, Computer and Telecommunications Engineering, University of Wollongong, Wollongong 2522, AustraliaSchool of Electrical and Data Engineering, University of Technology Sydney, Ultimo 2007, AustraliaSchool of Electrical and Data Engineering, University of Technology Sydney, Ultimo 2007, AustraliaSelf-interference (SI) is the key issue that prevents in-band full-duplex (IBFD) communications from being practical. Analog multi-tap adaptive filter is an efficient structure to cancel SI since it can capture the nonlinear components and noise in the transmitted signal. Analog least mean square (ALMS) loop is a simple adaptive filter that can be implemented by purely analog means to sufficiently mitigate SI. Comprehensive analyses on the behaviors of the ALMS loop have been published in the literature. This paper proposes a practical structure and presents an implementation of the ALMS loop. By employing off-the-shelf components, a prototype of the ALMS loop including two taps is implemented for an IBFD system operating at the carrier frequency of 2.4 GHz. The prototype is firstly evaluated in a single carrier signaling IBFD system with 20 MHz and 50 MHz bandwidths, respectively. Measured results show that the ALMS loop can provide 39 dB and 33 dB of SI cancellation in the radio frequency domain for the two bandwidths, respectively. Furthermore, the impact of the roll-off factor of the pulse shaping filter on the SI cancellation level provided by the prototype is presented. Finally, the experiment with multicarrier signaling shows that the performance of the ALMS loop is the same as that in the single carrier system. These experimental results validate the theoretical analyses presented in our previous publications on the ALMS loop behaviors.https://www.mdpi.com/1424-8220/20/1/270in-band full-duplexself-interference cancellationadaptive filteri/q imbalancealms loop |
| spellingShingle | Anh Tuyen Le Le Chung Tran Xiaojing Huang Yingjie Jay Guo Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective Sensors in-band full-duplex self-interference cancellation adaptive filter i/q imbalance alms loop |
| title | Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective |
| title_full | Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective |
| title_fullStr | Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective |
| title_full_unstemmed | Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective |
| title_short | Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective |
| title_sort | analog least mean square loop for self interference cancellation a practical perspective |
| topic | in-band full-duplex self-interference cancellation adaptive filter i/q imbalance alms loop |
| url | https://www.mdpi.com/1424-8220/20/1/270 |
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