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This article introduces a new over-the-air calibration method for millimeter wave phased arrays. Our method leverages the channel estimation process which is a fundamental part of any wireless communication system. By performing the channel estimation while changing the phase of an antenna element, the response of the element is obtained. Unlike prior work, our method includes all the system components and thus, spans the full chain. By overriding channel estimation, no additional circuits are required, and online calibration is possible without pausing the communication process. We tested our method on an eight-element-phased array at 24GHz which we designed and fabricated in PCB for verification. 

This paper proposes a new over-the-air (OTA) calibration method for millimeter wave phased arrays. Our method leverages the channel estimation process which is a fundamental part of any wireless communication system. By performing the channel estimation while changing the phase of an antenna element, the phase response of the element can be estimated. The relative phase of the phased array can also be obtained by collecting all the estimated phase responses with a shared reference state. Hence, the phase mismatches of the phased array can be resolved. Unlike prior work, our calibration method embraces all the array components such as power-divider, phase shifter, amplifier and antenna and thus, spans the full chain. By overriding channel estimation, our proposed technique does not require any additional circuits for calibration. Furthermore, the calibration can be performed online without the need to pause the communication. We tested our method on an eight element phased array at 24GHz which we designed and fabricated in PCB for verification. The measured beam patterns prove the viability of our proposed method. 

Millimeter Wave (mmWave) networks can deliver multi-Gbps wireless links that use extremely narrow directional beams. This provides us with a new opportunity to exploit spatial reuse in order to scale network throughput. Exploiting such spatial reuse, however, requires aligning the beams of all nodes in a network. Aligning the beams is a difficult process which is complicated by indoor multipath, which can create interference, as well as by the inefficiency of carrier sense at detecting interference in directional links. This paper presents BounceNet, the first many-to-many millimeter wave beam alignment protocol that can exploit dense spatial reuse to allow many links to operate in parallel in a confined space and scale the wireless throughput with the number of clients. Results from three millimeter wave testbeds show that BounceNet can scale the throughput with the number of clients to deliver a total network data rate of more than 39 Gbps for 10 clients, which is up to 6.6× higher than current 802.11 mmWave standards.