Radio apparatus for simulataneously transmitting and receiving signals using a simple frequency

• US 5,493,698 A
• Filed: 02/25/1994
• Issued: 02/20/1996
• Est. Priority Date: 02/26/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.), Aventis Pharma SA (Sanofi ), Tohoku Electric Power Company Incorporated
• Original Assignee: Fuji-Tekku Kabushiki Kaisha, Hitachi Denshi Kabushiki Kaisha, Tohoku Electric Power Company Incorporated
• Inventors: Suzuka, Kazuo, Shiraishi, Mitsuo, Suzuki, Kenichi, Suzuki, Osamu, Ohira, Sakari, Sumi, Fujio
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/202,217
• Time in Patent Office: 725 Days
• Field of Search: 455/67.1, 455/51.1, 455/72, 455/73, 455/78, 455/82, 455/84, 455/86, 455/226.1, 370/118, 370/29, 381/106
• US Class Current: 370/280
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04B 1/662 using a time/frequency relationship, e.g. time compression or expansion

Abstract

A radio apparatus having a unit for receiving a first signal from a first transceiver compressed in time by a predetermined rate, a unit for reproducing a first original signal from the first signal, a unit for receiving a second signal from a second transceiver compressed by the predetermined rate during the reception period of the first transceiver, a unit for reproducing a second original signal from the second signal, and a unit for adding the first and second original signals and outputting the added signal.

Claims

1. A radio apparatus for substantially simultaneous transmission and reception using a single frequency, and having a synchronizing signal generator unit for informing a callee of a switch timing between transmission and reception, a synchronizing signal detector unit for detecting a synchronizing signal contained in a signal received from a caller, and a transmission/reception switching unit for switching between transmission and reception synchronously with one of said detected synchronizing signal transmitted from the caller and a timing generated by the callee, in which a transmission signal is stored in a memory via a first A/D converter at a predetermined time interval, the stored data is read by reading out the signal from the memory at substantially half the predetermined time interval and applied to a modulator via a first D/A converter during a transmission period to transmit said transmission signal compressed in time by substantially half, a reception signal from a first transceiver compressed in time by substantially half is stored via a second A/D converter at the predetermined time interval, the stored data is read out from the memory at substantially twice the predetermined time interval so as to expand to the original signal of the reception signal and applied to a second D/A converter, said radio apparatus comprising:

means for receiving a signal from a first transceiver;

means for receiving a signal from a second transceiver compressed in time by substantially half during said transmission period;

a controller unit for selecting either performing duplex communication synchronously with said detected synchronizing signal of said first transceiver during the period said synchronizing signal is being detected or receiving said signal from said second transceiver during said transmission period; and

a third D/A converter and an adder, wherein if said signal from said second transceiver is to be received during said transmission period, said compressed signals from said first and second transceivers are stored in the memory via said second A/D converter, the stored data is read out from the memory at substantially twice the predetermined time interval, said read signal for said first transceiver is applied to said second D/A converter, said read signal for said second transceiver is applied to said third D/A converter, the outputs of said second and third D/A converters are applied to said adder, and the added signal is output from said adder as a reproduced signal from said first and second transceivers.

2. A radio apparatus according to claim 1, further comprising control means for providing said first D/A converter with the function of said third D/A converter, and controlling to apply an output of said first D/A converter to one of said modulator and said adder, wherein when a signal from said second transceiver is received, the signal from said second transceiver is stored via said second A/D converter, the stored data is read at substantially twice the predetermined time interval and applied via said first D/A converter to said adder.

3. A radio apparatus for substantially simultaneously transmitting and receiving signals using a single frequency, wherein a transmission period and a reception period in said radio apparatus are alternately set in operation, said radio apparatus comprising:

means for transmitting a first transmission signal to a first transceiver during said transmission period of said radio apparatus, said first transmission signal having been compressed in time axis by a predetermined rate;

means for receiving a second transmission signal from said first transceiver during said reception period of said radio apparatus, said second transmission signal having been compressed in time axis by the predetermined rate;

means for reproducing a first original signal from said second transmission signal;

means for receiving a third transmission signal from a second transceiver during the transmission period of said radio apparatus, said third transmission signal having been compressed in time axis by the predetermined rate;

means for reproducing a second original signal from said third transmission signal;

means for adding said first and second original signals, and outputting the added signal; and

control means for controlling said transmitting means and said third signal receiving means, and selecting either operation of said transmitting means transmitting said first transmission signal and said third signal receiving means receiving said third transmission signal during said transmission period of said radio apparatus.

4. A radio apparatus according to claim 3, wherein said control means further include means for transmitting said first transmission signal directly via a modulator during said transmission period and outputting said second transmission signal from said first transceiver directly via a demodulator.

5. A radio apparatus according to claim 3, wherein said predetermined rate is one-half or more.

6. A radio apparatus according to claim 3, further comprising means for selecting one of said first, second and third signals.

7. A radio apparatus for substantially simultaneously transmitting and receiving signals with a single frequency, comprising:

a synchronizing signal detector unit for detecting a synchronizing signal contained in a first reception signal received from a first transceiver;

a synchronizing signal generator unit for generating a switch timing signal between transmission and reception periods, said switching timing signal being synchronized with said synchronizing signal from said first transceiver;

a first A/D converter for converting an analog signal into a digital signal;

memory means coupled to said first A/D converter, for storing said digital signal at a predetermined time interval, said predetermined time interval being synchronized with said synchronizing signal;

a first D/A converter for converting the digital signal read out from said memory means into an analog signal, said digital signal being read out from said memory means at substantially half said predetermined time interval so as to compress the digital signal supplied to said first D/A converter;

means for modulating the compressed analog signal from said first D/A converter, and transmitting the modulated signal as a transmission signal during said transmission period;

means for receiving and demodulating the first reception signal from said first transceiver during said reception period and for receiving and demodulatinq a second reception signal from a second transceiver during said transmission period, said first reception signal having been compressed in time axis by substantially half the predetermined time interval and said second reception signal having been compressed in time axis by substantially half the predetermined time interval;

a second A/D converter coupled to said memory means, for converting the demodulated first reception signal into a digital first reception signal and for converting the demodulated second reception signal into a digital second reception signal said digital first reception signal being stored in said memory means and said diqital second reception signal being stored in said memory means;

a second D/A converter coupled to said memory means, for converting the digital first reception signal from said memory means into an analog first reception signal, said digital first reception signal being read out from said memory means at substantially twice the predetermined time interval so as to expand said first digital reception signal in time axis to be an original signal which is supplied to said second D/A converter;

control means for selecting either performing duplex communication in synchronism with the detected synchronizing signal during the period when said synchronizing signal is being detected or receiving said second reception signal from said second transceiver during said transmission period;

a third D/A converter coupled to said memory means for converting said digital second reception signal stored in said memory means into a second analog reception signal; and

an adder coupled to said second and third D/A converters, wherein

when said second reception signal from said second transceiver is received during said transmission period, the compressed first and second reception signals are stored in said memory means through said second A/D converter, the stored reception signals are read out at substantially twice the predetermined time interval, the read out digital first reception signal is supplied to said second D/A converter, the read out digital second reception signal is supplied to said third D/A converter, and said adder adds said analog first reception signal from said second D/A converter with said analog second reception signal from said third D/A converter.