Wireless transmission/reception system including transmitting terminal producing multiple frequency local oscillation signals and receiving terminal storing a local oscillation signal

• US 5,355,523 A
• Filed: 07/28/1992
• Issued: 10/11/1994
• Est. Priority Date: 08/09/1991
• Status: Expired due to Term

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Inage, Toshiaki, Konishi, Hirofumi, Kuboyama, Haruhiro, Ogawa, Haruo, Ueno, Yoshiaki, Shogaki, Yoshihiro, Morino, Shinji, Hyosu, Haruhiko
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): PHAM, CHI H
• Application Number:
  US07/920,874
• Time in Patent Office: 805 Days
• Field of Search: 455/19, 455/20, 455/23, 455/46, 455/51.1, 455/68-72, 455/88, 455/201-203, 455/259, 455/313, 455/75, 455/76, 455/102, 455/86, 455/87
• US Class Current: 455/71
• CPC Class Codes: H04B 1/405 with multiple discrete channels

Abstract

A wireless transmission system includes a plurality of terminal units, a specific one of which is provided with a transmission/receiving circuit that transmits a reference signal of a local oscillation frequency, while all others of which are provided respectively with a transmission/receiving circuit that prepares, on the basis of the reference signal received, a local oscillation frequency signal for frequency conversion of transmitting/receiving frequency signal and intermediate frequency signal, to thereby realize the system at lower costs even when a high local oscillation frequency is employed.

Claims

1. A wireless transmission/reception system including a plurality of terminal units, a first of said terminal units including a transmitting/receiving circuit for transmitting a transmitted frequency signal resulting from mixing of an intermediate frequency signal with a local oscillation signal having a local oscillation frequency and for transmitting a reference signal at the local oscillation frequency, the other terminal units each including a transmitting/receiving circuit for receiving the transmitted frequency signal and the reference signal, for detecting the reference signal, and for generating from the detected reference signal the local oscillation frequency signal for frequency conversion of the transmitted frequency signal into the intermediate frequency signal, wherein a plurality of different local oscillation frequencies are generated in said first terminal unit, and one of the local oscillation frequencies is selected as the reference signal and for mixing with the intermediate frequency signal to produce the transmitted frequency signal in synchronism with a clock signal input to said first terminal unit for transmission of the transmitted frequency signal.

2. A wireless transmission/reception system including a plurality of terminal units a first of said terminal units including a transmitting/receiving circuit for transmitting a transmitted frequency signal resulting from mixing of an intermediate frequency signal with a local oscillation signal having a local oscillation frequency and for transmitting a reference signal at the local oscillation frequency, the other terminal units each including a transmitting/receiving circuit for receiving the transmitted frequency signal and the reference signal, for detecting the reference signal, and for generating from the detected reference signal the local oscillation frequency signal for frequency conversion of the transmitted frequency signal into the intermediate frequency signal, wherein each of said transmitting/receiving circuits of said other terminal units comprises means for storing the local oscillation frequency signal generated from the detected reference signal and providing the stored local oscillation frequency signal for the frequency conversion when the reference signal is not received from said first terminal unit.