RECEIVING DEVICE AND METHOD FOR REMOVING TRANSMISSION LEAK SIGNAL

• Main Authors: FUKINO KOJI, SHINFUKU YOSHIFUMI
• Format: Patent
• Language: English; Japanese
• Published: 16.10.2014
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

PROBLEM TO BE SOLVED: To suppress reduction of removal performance of a transmission leak signal when gain or attenuation is discretely switched.SOLUTION: A receiving device includes an AGC circuit for discretely setting gain or attenuation for a receiving signal and a cancellation circuit for removing a transmission leak signal included in the receiving signal by forming a replica signal of the transmission leak signal and subtracting the replica signal from the receiving signal. The cancellation circuit includes a plurality of memories for holding tap coefficients of a filter corresponding to gain or attenuation set in the AGC circuit and a selector for switching the memories and is configured so as to switch the memories of the cancellation circuit to the memory corresponding to the set gain or attenuation interlocking with switching of the gain of the AGC circuit. 【課題】利得又は減衰を離散的に切り替えた時の送信リーク信号の除去能力の低下を抑制する。【解決手段】受信信号に対する利得又は減衰を離散的に設定するＡＧＣ回路と、送信リーク信号のレプリカ信号を形成し、受信信号からレプリカ信号を減算して前記受信信号中に含まれる送信リーク信号を除去するキャンセル回路と、を備え、キャンセル回路は、ＡＧＣ回路に設定する利得又は減衰に対応するフィルタのタップ係数を保持する複数のメモリと、前記メモリを切り替えるセレクタとを含み、ＡＧＣ回路の利得の切り替えに連動して、キャンセル回路のメモリを当該設定された利得又は減衰に対応するメモリに切り替える。【選択図】図１