RADIO TRANSMITTER RECEIVER INCLUDING LEVEL AND ANTENNA DIRECTION CONTROL CIRCUITRY

• US 3,781,890 A
• Filed: 11/20/1970
• Issued: 12/25/1973
• Est. Priority Date: 11/20/1969
• Status: Expired due to Term

• Current Assignee: Marcel Louis Boyer
• Original Assignee: Marcel Louis Boyer
• Inventors: Boyer, Marcel Louis
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): McCabe, Denis H.
• Application Number:
  US05/091,370
• Time in Patent Office: 1,131 Days
• Field of Search: 325/38A,55,40 343/1CS
• US Class Current: 342/367
• CPC Class Codes: H04W 88/188 using frequency address codes

Abstract

The invention concerns the field of point-to-point communications in a network of stations equipped for selective calling. It concerns a coding system partially of the numerical types, partially of the analogical type, combined with a device for enabling maximum output at the transmission level. The main applications are in mobile communications, in particular, between airplanes.

Claims

1. A radio transmitter-receiver for operation in one of k individual vocal frequency bands in an overall frequency range made up of k + 1 frequency bands, comprising a transmitter section for transmitting both communication and control signals, a receiver section for receiving signals from another transmitter-receiver, antenna means selectively connectable to said transmitter section and said receiver section, and call coder means for generating a pulsed code of n digits for modulation in one of said k individual vocal frequency bands, whereby a total of 2nk pulsed codes are available as the output of said call coder means, said call coder means being connected to said transmitter section for supplying the pulsed code thereto for transmission by said transmitter section.

2. A radio transmitter-receiver as defined in claim 1, wherein said overall frequency range is made up of k individual vocal frequency bands and a common frequency band, said call coder means including secondary coder means for generating a communication code in the common frequency band.

3. A radio transmitter-receiver as defined in claim 2, wherein said antenna means includes an omnidirectional antenna and a plurality of directional antennas and antenna selector switching means for connecting selected ones of said antennas to said transmitter section and said receiver section, said call coder means further including tertiary coder means responsive to said antenna selector switching means for generating in said common frequency band, generated by said secondary coder means, respective antenna codes significant of each directional antenna for transmission by said transmitter section.

4. A radio trAnsmitter-receiver as defined in claim 3, wherein said common frequency band includes a narrow frequency band in which said communication code and said antenna codes are transmitted at a transmission speed lower than that at which the remainder of said common bands and said individual bands operate.

5. A radio transmitter-receiver as defined in claim 4, wherein the ratio of the widths of said narrow frequency band and said common frequency band is substantially equal to the ratio of the widths of said common frequency band and said overall frequency range.

6. A radio transmitter-receiver as defined in claim 5, further including level detecting means connected to the output of said transmitter section for generating a first coded signal indicative of the level of the output of said receiver section.

7. A radio transmitter-receiver as defined in claim 6, wherein said level detecting means includes first through fourth filter circuits for passing said overall frequency range, one individual frequency band, said common frequency band and said narrow frequency band, respectively, a pair of demodulators, a comparator circuit connected to compare the outputs from said demodulators, and switching circuitry for selectively connecting inputs of selected pairs of said first through fourth filter circuits to the output of said receiver section and outputs of the selected filter circuit pairs to inputs of said demodulators, said comparator circuit output providing an indication of the reception level in the receiver section.

8. A radio transmitter-receiver as defined in claim 7, wherein said level detecting means further includes counter means for counting the initially received communications and the initial transmissions, said switching circuitry being responsive to said counter means to connect three pairs of filter circuits sequentially between said receiver section and said demodulators to obtain comparisons respectively of (a) the individual frequency band and the overall frequency range, (b) the common frequency band and the overall frequency range, and (c) the narrow frequency band and the common frequency band.

9. A radio transmitter-receiver as defined in claim 7, wherein said level detecting means further includes threshold circuit means connected to the output of said comparator circuit for providing different threshold signals defining respective level ranges, said threshold circuit means being adapted to produce a unidriectional voltage in the lowest level range in response to said comparator circuit indicating a reception level in a predetermined minimum range.

10. A radio transmitter-receiver as defined in claim 9, wherein said level detecting means further includes level signalling means for selecting one of a plurality of signalling frequencies outside said overall range of frequencies for transmission by said transmitter section in response to the level indicated by the threshold signal received from said threshold circuit means.

11. A radio transmitter-receiver as defined in claim 10, further including level section means for attenuating the output from said transmitter section in response to receipt of a first coded signal through said receiver section from another radio transmitter-receiver.

12. A radio transmitter-receiver as defined in claim 3, further including detection means responsive to the receipt of antenna codes through said receiver section from another transmitter-receiver for detecting the strongest received antenna code.

13. A radio transmitter-receiver as defined in claim 12, wherein said call coder means further includes additional coder means for generating an antenna identifying signal applied to said transmitter section indicating the strongest received antenna code as detected by said detection means.

14. A radio transmitter-receiver as defined in claim 13, further including antenna selection means responsive to receipt of an antenna identifying signal at the output of said receiver section for actuating sAid antenna selector switching means to connect said transmitter section to a specific one of said directional antennas.

15. A radio transmitter-receiver as defined in claim 14, further including level selection means for attenuating the output from said transmitter section in response to receipt of a first coded signal through said receiver section from another radio transmitter-receiver.

16. A radio transmitter-receiver as defined in claim 15, further including level detecting means connected to the output of said transmitter section for generating a first coded signal indicative of the level of the output of said receiver section.

17. A radio transmitter-receiver as defined in claim 3, further including antenna selection means responsive to receipt of an antenna identifying signal at the output of said receiver section for actuating said antenna selector switching means to connect said transmitter section to a specific one of said directional antennas.

18. A radio transmitter-receiver as defined in claim 1, wherein said call coder means includes means for modulating one of said k individual vocal frequency bands with said generated pulsed code.