Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications
High frequency (millimeter wave and higher) systems are being used for curb-to-home services and indoor networks with fixed transmitter and receivers. However, the environment between them can shift due to moving flora and fauna causing sudden blockages. To mitigate outages due to blocking, we inves...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IEEE
2022-01-01
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| Series: | IEEE Access |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9841578/ |
| _version_ | 1798042065483857920 |
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| author | Sarah Kate Wilson Milica Stojanovic Muriel Medard Kurt Schab |
| author_facet | Sarah Kate Wilson Milica Stojanovic Muriel Medard Kurt Schab |
| author_sort | Sarah Kate Wilson |
| collection | DOAJ |
| description | High frequency (millimeter wave and higher) systems are being used for curb-to-home services and indoor networks with fixed transmitter and receivers. However, the environment between them can shift due to moving flora and fauna causing sudden blockages. To mitigate outages due to blocking, we investigate the use of a two-beam system rather than a conventional single line-of-sight (LOS) beam. A two-beam system requires a design that can adjust both the transmit phase and delay on one of the beams to ensure a strong signal when both beams are not blocked, and the ability to adapt the transmission rate when the receiver power drops due to intermittent blockages on either beam. We propose a low-complexity co-phasing strategy in which the transmitter guesses the phase and delay offset between the two beams until the receiver indicates a satisfactory channel has been established. Exact co-phasing of the beams is not required and the average number of guesses needed to find an appropriate delay and phase is relatively small. Once the link has been established, the transmitted signal power is split between the two beams to achieve maximum throughput for a fixed total power budget limit. The resulting scheme is not only computationally efficient, but is also robust to channel estimation errors that typically plague transmit adaptation strategies. Numerical results demonstrate the effectiveness of the approach, showing that a capacity within 0.1 dB of perfect co-phasing can be achieved with fewer than 100 guesses. In 90 % of the cases, 25 guesses were required on average to achieve a power that is within 0.1 dB of the optimum. |
| first_indexed | 2024-04-11T22:30:18Z |
| format | Article |
| id | doaj.art-77199d4d00ac460f8936b37e93b8ba2e |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-04-11T22:30:18Z |
| publishDate | 2022-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-77199d4d00ac460f8936b37e93b8ba2e2022-12-22T03:59:26ZengIEEEIEEE Access2169-35362022-01-0110809898099810.1109/ACCESS.2022.31941229841578Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave CommunicationsSarah Kate Wilson0https://orcid.org/0000-0002-3530-2207Milica Stojanovic1Muriel Medard2https://orcid.org/0000-0003-4059-407XKurt Schab3https://orcid.org/0000-0002-4228-9856Department of Electrical and Computer Engineering, Santa Clara University, Santa Clara, CA, USADepartment of Electrical Engineering, Northeastern University, Boston, MA, USADepartment of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USADepartment of Electrical and Computer Engineering, Santa Clara University, Santa Clara, CA, USAHigh frequency (millimeter wave and higher) systems are being used for curb-to-home services and indoor networks with fixed transmitter and receivers. However, the environment between them can shift due to moving flora and fauna causing sudden blockages. To mitigate outages due to blocking, we investigate the use of a two-beam system rather than a conventional single line-of-sight (LOS) beam. A two-beam system requires a design that can adjust both the transmit phase and delay on one of the beams to ensure a strong signal when both beams are not blocked, and the ability to adapt the transmission rate when the receiver power drops due to intermittent blockages on either beam. We propose a low-complexity co-phasing strategy in which the transmitter guesses the phase and delay offset between the two beams until the receiver indicates a satisfactory channel has been established. Exact co-phasing of the beams is not required and the average number of guesses needed to find an appropriate delay and phase is relatively small. Once the link has been established, the transmitted signal power is split between the two beams to achieve maximum throughput for a fixed total power budget limit. The resulting scheme is not only computationally efficient, but is also robust to channel estimation errors that typically plague transmit adaptation strategies. Numerical results demonstrate the effectiveness of the approach, showing that a capacity within 0.1 dB of perfect co-phasing can be achieved with fewer than 100 guesses. In 90 % of the cases, 25 guesses were required on average to achieve a power that is within 0.1 dB of the optimum.https://ieeexplore.ieee.org/document/9841578/Beamformingcommunications technologyfeedbackmmWavesystem designmultipath |
| spellingShingle | Sarah Kate Wilson Milica Stojanovic Muriel Medard Kurt Schab Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications IEEE Access Beamforming communications technology feedback mmWave system design multipath |
| title | Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications |
| title_full | Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications |
| title_fullStr | Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications |
| title_full_unstemmed | Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications |
| title_short | Random Guessing for Beam Alignment: A Low Complexity Strategy for Reducing Blockage in mmWave Communications |
| title_sort | random guessing for beam alignment a low complexity strategy for reducing blockage in mmwave communications |
| topic | Beamforming communications technology feedback mmWave system design multipath |
| url | https://ieeexplore.ieee.org/document/9841578/ |
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