GB1088261A - A frequency-diversity transmitter-receiver - Google Patents

A frequency-diversity transmitter-receiver

Info

Publication number
GB1088261A
GB1088261A GB151665A GB151665A GB1088261A GB 1088261 A GB1088261 A GB 1088261A GB 151665 A GB151665 A GB 151665A GB 151665 A GB151665 A GB 151665A GB 1088261 A GB1088261 A GB 1088261A
Authority
GB
United Kingdom
Prior art keywords
signal
supplied
information signal
carrier wave
frequency
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB151665A
Inventor
Masahisa Miyagi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US418672A priority Critical patent/US3390335A/en
Priority to FR999207A priority patent/FR1425568A/en
Application filed by Nippon Electric Co Ltd filed Critical Nippon Electric Co Ltd
Priority to GB151665A priority patent/GB1088261A/en
Publication of GB1088261A publication Critical patent/GB1088261A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/12—Frequency diversity

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Transmission System (AREA)

Abstract

1,088,261. Radio signalling. NIPPON ELECTRIC CO. Ltd. Jan. 13, 1965, No. 1516/65. Heading H4L. In a radio communication system an information signal is transmitted on one carrier wave together with a narrower band pilot signal on a different carrier wave and the receiver comprises means for determining which carrier wave provides the best signal and for transmitting back a control signal to provide (if necessary) automatic changeover of the information signal transmission to that carrier wave. As shown, the information signal from source 11 and pilot signal from source 12 are supplied via a changeover switch 13, controlled by circuit 13<SP>1</SP> to respective modulators 14a, 14b. The resulting modulated carrier waves #1, #2 are supplied via variable attenuators 16a, 16b, controlled by circuit 16<SP>1</SP>, wide band amplifier 18 and filter 19t to the transmitting portion of aerial 19. The incoming signals #3, #4 from the remote transmitter are supplied via the receiving portion of aerial 19 to a frequency-changer 22 whose output is supplied preferably via I.F. amplifiers (not shown) to a pair of frequency-changers 25, 26. The outputs of frequency-changers 25, 26 are supplied via a change-over switch 27, controlled by circuit 27<SP>1</SP>, to demodulators 27a, 27b providing the information and pilot signal respectively. The information signal is supplied to a utilization device 6 and the noise levels of the two signals are compared at 32 to provide a signal indicating which output has the lower noise level, this signal having a frequency lower than the lower limit of the band of the information signal, and being added to the information signal at 11 for transmission to the remote receiver. The control signal is also supplied to the receiver switch controller 27<SP>1</SP> to operate the changeover switch 27 if necessary. At the remote receiver this control signal is supplied to a circuit 35 to operate a changeover switch 13 accordingly, and also attenuators 16a, 16b, so that the signals are transmitted at the appropriate levels. In this way, the transmitter at each station automatically selects the carrier wave giving the best signal/ noise ratio for the transmission of the information signal.
GB151665A 1963-12-31 1965-01-13 A frequency-diversity transmitter-receiver Expired GB1088261A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US418672A US3390335A (en) 1963-12-31 1964-12-16 Frequency-diversity transmitter-receiver
FR999207A FR1425568A (en) 1964-12-18 1964-12-18 frequency diversity transceiver
GB151665A GB1088261A (en) 1965-01-13 1965-01-13 A frequency-diversity transmitter-receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB151665A GB1088261A (en) 1965-01-13 1965-01-13 A frequency-diversity transmitter-receiver

Publications (1)

Publication Number Publication Date
GB1088261A true GB1088261A (en) 1967-10-25

Family

ID=9723329

Family Applications (1)

Application Number Title Priority Date Filing Date
GB151665A Expired GB1088261A (en) 1963-12-31 1965-01-13 A frequency-diversity transmitter-receiver

Country Status (1)

Country Link
GB (1) GB1088261A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2318482A (en) * 1996-10-16 1998-04-22 Ico Services Ltd Channel selection in a radio communication system employing diversity
US6771627B1 (en) 1997-10-15 2004-08-03 Ico Services Limited Method of operating a mobile station for diversity communication

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2318482A (en) * 1996-10-16 1998-04-22 Ico Services Ltd Channel selection in a radio communication system employing diversity
GB2318482B (en) * 1996-10-16 2001-06-13 Ico Services Ltd Communication system
US6771627B1 (en) 1997-10-15 2004-08-03 Ico Services Limited Method of operating a mobile station for diversity communication

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