RADIO STATION APPARATUS AND SIGNAL TRANSMISSION METHOD THEREOF
 Inventors: Yasunori Yoshizawa; Shinichi Ohmagari. both of Tokyo. Japan
 Assignee: NEC Corporation, Japan
 Appl. No.: 405,908
 Filed: Mar. 17, 1995
 Foreign Application Priority Data
Apr. 26, 1994 [JP] Japan 6-088588
 Int CI.6 H04B 1/38; H04B 1/40
 U.S. CI 375/268; 375/300
 Field of Search 375/268. 269,
 References Cited
U.S. PATENT DOCUMENTS 4,755,773 7/1988 Ohmagari .
4,907,291 3/1990 Yamamoto 455/78
4,934,983 6/1990 Miyo 455/8
FOREIGN PATENT DOCUMENTS
2469658 5/1987 European Pat. Off. . 261600 9/1987 European Pat. Off. . 62-274934 11/1987 Japan .
US005712876A [ii] Patent Number: 5,712,876  Date of Patent: Jan. 27, 1998
Primary Examiner—Melvin Marcelo
Attorney, Agent, or Firm—Ostrolenk, Faber, Gerb & Soffen.
The invention provides a radio station apparatus which converts a plurality of inputs digital transmission signals whose data transmission rates are different into an analog signal, modulates the analog signal with a radio carrier frequency and transmits the modulated signal, and a signal transmission method through radio station apparatus. The radio station apparatus of the present invention includes indoor unit 10, outdoor unit 20, and coaxial cable 60 which connects indoor unit 10 and outdoor unit 20 to each other. An inputted first binary digital signal is converted into a serial second binary digital signal by parallel/serial converter 2 and modulated by amplitude shift keying (ASK) into a third binary digital signal by modulator 13 with carrier f3 (Hz) whose frequency is a common multiple of respective value of n (sampling number)xm (quantization bit number) times the data rate of all inputted data. The third binary digital signal is multiplexed by frequency division multiplexing with another signal or signals by multiplexer 3 and transferred to outdoor unit 20 through coaxial cable 60. In outdoor unit 20, transferred third binary digital signal is demultiplexed and converted into an analog signal by a D/A converter.
11 Claims, 3 Drawing Sheets