Simultaneous transmission and reception system by nonlinear signal process

✍ Scribed by Masanori Shinriki; Kiyonobu Abe; Fujio Shimano

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 403 KB
• Volume: 83
• Category: Article
• ISSN: 8756-6621
• DOI: 10.1002/(sici)1520-6424(200003)83:3<13::aid-ecja2>3.0.co;2-l

✦ Synopsis

A simultaneous transmission and reception system is studied in which transmission and reception are always possible without preventing the functions of the receiver near the transmitter, and a method is proposed for eliminating the interference wave as an important technical challenge in this system. The proposed system is an interference suppression method using a nonlinear circuit. Interference suppression by a nonlinear circuit is assigned to each element of the array antenna. After the interference wave is eliminated in the nonlinear circuit, the intermodulation components due to nonlinearity and the residual interference are suppressed by spatial averaging so that only the desired wave is extracted. In this method, no correlation is used for discrimination of the interference and the desired wave, nor are complex calculations required. Therefore, interference elimination is accomplished instantaneously. Also, in principle no phase adjustment is needed in the interference elimination. Therefore, the method is extremely effective for a broadband FM noise interference wave. The improvement characteristics of the interference elimination in this system are studied theoretically. Experiments are carried out for the conventional echo canceller system and the proposed system. The superiority of the interference elimination characteristics of the proposed system is described qualitatively.