Single-Frequency Full-Duplex

受信アンテナに回り込む送信信号を雑音レベルにまで減衰させることで,同一周波数全二重無線通信が実現できる.同一周波数全二重無線通信によれば,帯域利用効率を向上させることができるのみならず,パケット衝突検知の高度化,隠れ端末問題の緩和,マルチホップ転送時の低遅延化なども可能となる.しかしながら,これまでの研究では,送受信回路で生じる非線形雑音の除去や同一周波数全二重無線通信の性能を活かすMACプロトコルに課題を残している.本研究は,同一周波数全二重無線通信向け平面アンテナ,アナログ回路,適応ディジタルフィルタを組み合わせた同一周波数全二重無線通信の物理層を検討するとともに,同一周波数全二重無線通信に特化したMACプロトコルの設計を行う.現在,水平面無指向性と比帯域11 %で50 dB以上の減衰量とを確保できる同一周波数全二重無線通信向け平面アンテナとデジタルキャンセラの評価を行っている.

Single-frequency full-duplex wireless communication not only increases the efficiency of the bandwidth utilization, but also mitigates the hidden terminal problem and enhances the performance of the packet collision detection. It also decreases the multihop transmission delay. Single-frequency full-duplex wireless communication can be achieved by reducing the self-interference at the receive antenna from the transmit antenna to the background noise level. However, previous works did not provide sufficient cancellation performance, and the design of efficient MAC protocol has not been fully discussed yet. Therefore, we are aiming to design an interference cancellation technique combining antenna cancellation, analog-circuit cancellation and an adaptive digital canceller, and to develop a MAC protocol for Single-frequency full-duplex wireless communications. Currently, we are working on developing a planer antenna that has omnidirectional radiation pattern on horizontal plane and 50 dB self-interference for a bandwidth of 11%. We are also implementing and evaluating the developed antenna and digital canceller to realize the Single-frequency full duplex wireless communication.