Signal transmitting and receiving device

• US 4,020,449 A
• Filed: 05/19/1975
• Issued: 04/26/1977
• Est. Priority Date: 05/22/1974
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ito, Tetsuo, Nishihara, Motohisa
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US05/578,767
• Time in Patent Office: 708 Days
• Field of Search: 340/5 R, 340/171 PF, 340/171 A, 340/148, 340/16 C, 340/15
• US Class Current: 367/134
• CPC Class Codes: H04B 11/00 Transmission systems employing sonic, ultrasonic or infrasonic waves
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence

Abstract

A signal to be transferred comprises a plurality of patterns each including a time region containing a plurality of frequency signals and a time region containing no frequency signal. When a signal to be transmitted is given in the form of numeric information, this signal is automatically patterned by a transmitter unit to provide a period containing predetermined frequency signals and a period containing no frequency signal. A receiver unit reproduces the sequentially transmitted frequency signals on the basis of the reception of the first transmitted frequency signal.

Claims

1. An imformation transmitting and receiving device comprising, in combination:

a transmitter unit for encoding and transmitting a piece of data to be transmitted as a frequency signal-time pattern, said pattern being comprised of

a plurality n- 1 of frequency signals, different from each other and each of which has a duration corresponding to a prescribed time interval t, and

an additional time interval t occupied by no frequency signal,

so that said frequency signal-time pattern occupies n sequential time intervals, n- 1 of which contain signals of respectively different frequencies, and

wherein the leading interval of time is occupied by one of said plurality n- 1 of frequency signals; and

a receiver unit for receiving the piece of data encoded and transmitted by said transmitter unit, for detecting the frequency signal-time pattern, and for decoding the order of the frequency signals as contained within said pattern.

2. An information transmitting and receiving device according to claim 1, wherein said transmitter unit includes

a first section receiving a respective piece of data in the form of numeric information and converting said numeric information into a pulse train corresponding to said frequency-time pattern,

a second section storing the pulses contained in said pulse train, and

a third section, responsive to the output of said second section, for generating said frequency signals during successive respective intervals of time.

3. An information transmitting and receiving device according to claim 2, wherein said first section contains

first means for comparing said numeric information with a first predetermined constant, and

second means for supplying to said first means a value equivalent to said numeric information minus said first predetermined constant when said first means produces its output indicating the said numeric information is larger than said first predetermined constant and for supplying to said first means a second predetermined constant smaller than said first predetermined constant when said first means produces its output indicating that said numeric information is smaller than said first predetermined constant.

4. An information transmitting and receiving device according to claim 1, wherein said receiver unit includes

a first unit having a plurality of receiving elements of the same number as said frequency signals for independently detecting said respective frequency signals,

a second section, responsive to the output from one of said receiving elements, for producing output signals at intervals corresponding to said successive time intervals respectively, and

a third section, responsive to the outputs of said first section and the outputs of said second section, for reproducing said frequency signal-time pattern.

5. A method of communication between transmitter and receiver stations comprising the steps of

a. encoding and transmitting, at said transmitter station, individual pieces of data, each as a respective frequency signal-time pattern, said pattern being comprised of a plurality n- 1 of frequency signals, different from each other and each of which has a duration corresponding to a prescribed time interval t, and

an additional time interval t occupied by no frequency signal,

so that said frequency signal-time pattern occupies n sequential time intervals

n- 1 of which contain signals of respectively different frequencies, and

wherein the leading interval of time is occupied by one of said plurality n- 1 of frequency signals;

b. receiving, at said receiver station, each piece of data as encoded and transmitted at said transmitter station;

c. detecting each frequency signal-time pattern of which the respective pieces of data are formed; and

e. decoding the order of the frequency signals contained within each pattern to thereby recover the originally encoded pieces of data.