LoneSTAR: Analog Beamforming Codebooks for Full-Duplex Millimeter Wave Systems

TL;DR

LoneSTAR introduces specialized analog beamforming codebooks for full-duplex mmWave systems, enabling high gain, broad coverage, and effective self-interference mitigation without additional cancellation techniques.

Contribution

It presents a novel codebook design framework that shapes beams to reject self-interference while maintaining beamforming gain, suitable for full-duplex mmWave communication.

Findings

LoneSTAR codebooks outperform conventional ones in self-interference mitigation.

They enable full-duplex operation with lower SNR requirements.

They support beam alignment and reduce the need for additional cancellation.

Abstract

This work develops LoneSTAR, a novel enabler of full-duplex millimeter wave (mmWave) communication systems through the design of analog beamforming codebooks. LoneSTAR codebooks deliver high beamforming gain and broad coverage while simultaneously reducing the self-interference coupled by transmit and receive beams at a full-duplex mmWave transceiver. Our design framework accomplishes this by tolerating some variability in transmit and receive beamforming gain to strategically shape beams that reject self-interference spatially while accounting for digitally-controlled analog beamforming networks and self-interference channel estimation error. By leveraging the coherence time of the self-interference channel, a mmWave system can use the same LoneSTAR design over many time slots to serve several downlink-uplink user pairs in a full-duplex fashion without the need for additional self-interference cancellation. Compared to those using conventional codebooks, full-duplex mmWave systems employing LoneSTAR codebooks can mitigate higher levels of self-interference, tolerate more cross-link interference, and demand lower SNRs in order to outperform half-duplex operation -- all while supporting beam alignment. This makes LoneSTAR a potential standalone solution for enabling simultaneous transmission and reception in mmWave systems, from which it derives its name.