Performance of Baseband-Bandlimited Multilevel FM with Discriminator Detection for Digital Mobile Telephony

Yoshihiko AKAIWA  Ichiro TAKASE  Susumu KOJIMA  Masao IKOMA  Noboru SAEGUSA  

IEICE TRANSACTIONS (1976-1990)   Vol.E64   No.7   pp.463-469
Publication Date: 1981/07/25
Online ISSN: 
Print ISSN: 0000-0000
Type of Manuscript: PAPER
Category: Transmission Systems

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Performance of multilevel FM with discriminator detection is studied for digital speech transmission in mobile radio channels. New transmit- and receive-baseband filter configurations in digital FM are considered. The low-pass filters are characterized by a square root of the raised cosine Nyquist filter. The present method is simple as an analog FM and has high immunity against fast fading. It is shown that digital speech can be transmitted with a 4-level FM and a 16 kbit/s adaptive delta modulation under a 25 kHz channel spacing, where the relative interchannel interference power is around -70 dB.