Bidirectional digital serial interface for communication digital signals including digitized audio between microprocessor-based control and transceiver units of two-way radio communications equipment

• US 5,007,050 A
• Filed: 03/27/1987
• Issued: 04/09/1991
• Est. Priority Date: 03/27/1987
• Status: Expired due to Fees

• Current Assignee: Teletec Corporation
• Original Assignee: Teletec Corporation
• Inventors: Fussell, John P., Rogers, Aaron S., Hsu, Ming-Chyuan, Kasparian, Kaspar A.
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US07/031,003
• Time in Patent Office: 1,474 Days
• Field of Search: 455/14, 455/53, 455/54, 455/88, 375/7, 375/8, 370/77, 370/95, 370/29, 370/4
• US Class Current: 370/280
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions

Abstract

A digital serial interface system is provided for communicating digital signals including digitized audio between microprocessor-based Control and Transceiver Units of two-way radio communications equipment. The system of the invention essentially comprises three subsystems: (1) an interface in the microprocessor-based Control Unit, (2) an interface in the microprocessor-based Transceiver Unit and (3) a two-way medium for linking the two units. Various signals and audio in the Control Unit interact with a software-driven microprocessor of the Control Unit and are digitized and then translated into a serial format, organized in channel groups through a TDM (Time Division Multiplex)/PCM (Pulse Code Modulation) process and transmitted in frames through a two-way medium to the Transceiver Unit which is also microprocessor-based and incorporates a similar interface. The digital data communicated to the Transceiver Unit then undergoes a reverse process. The Interface System is duplex (bidirectional). A preferred embodiment of the digital serial interface system for two-way radio equipment includes a three channel TDM/PCM bus structure scheme, operated in a synchronous full duplex mode using the Manchester II (Biphase-L) format. Various further embodiments include: an optical fiber link medium between a Control Unit and its Transceiver Unit(s), the addition of remote takeover of programming and controls, audio enhancement of receivers during scanning, encryption/decryption systems, cloning of programs between multiple units, control of multiple transceivers through one Control Unit and other added enhancements.

Claims

1. A digital serial communications link comprising:

(a) a first time division multiplexed full duplex digital interface for a two-way radio having a means for transmitting and receiving time-division multiplexed pulse code modulation signals;

(b) a second time division multiplexed full duplex digital interface for a two-way radio having a means for transmitting and receiving time-division multiplexed pulse code modulation signals; and

(c) a bidirectional time division multiplexed full duplex communicating medium connecting said first time division multiplexed full duplex digital interface with said second time division multiplexed full duplex digital interface.

2. The digital serial communicating link of claim 1 further comprising a means for storing and retrieving digital signals connected to said first time division multiplexed full duplex digital interface.

3. The digital serial communication link of claim 1 wherein said pulse code modulation signals are transmitted and received by Manchester II (biphase-L) format.

4. The digital serial communication link of claims 1 or 3 wherein said time-division multiplexed pulse code modulation signals are command or status signals and digitized audio.

5. The digital serial communication link of claim 1 or 3 wherein said first and second time division multiplexed full duplex digital interface provide means for serializing and deserializing said signals.

6. The digital serial communication link of claim 5 wherein said means for serializing and deserializing signals is a time-division multiplexor/demultiplexor.

7. The digital serial communication link of claim 1 wherein said bidirectional time division multiplexed full duplex communicating medium is a two or four path link.

8. The digital serial communication link of claim 7 wherein said bidirectional time division multiplexed full duplex communicating medium is infrared.

9. The digital serial communication link of claim 7 wherein said bidirectional time division multiplexed full duplex communicating medium is an optical fiber.

10. The digital serial communication link of claim 9 wherein said means for transmitting and receiving time division multiplexed pulse code modulation signals is a Manchester II encoder/decoder.

11. A digital communication link comprising:

(a) a first time division multiplexed full duplex digital interface for a two-way radio including means for serializing and deserializing signals including digitized audio;

(b) a second time division multiplexed full duplex digital interface for a two-way radio including means for serializing and deserializing signals including digitized audio, and;

(c) a synchronous bidirectional time division multiplexed full duplex communicating medium connecting said first time division multiplexed full duplex digital interface with said second time division multiplexed full duplex digital interface.

12. The digital communication link of claim 11 wherein said synchronous bidirectional time division multiplexed full duplex communicating medium is a two or four path link.

13. The digital communication link of claim 12 wherein said synchronous bidirectional time division multiplexed full duplex communicating medium is infrared.

14. The digital communication link of claim 12 wherein said synchronous bidirectional time division multiplexed full duplex communication medium is an optical fiber.

15. The digital communication link of claim 11 further comprising a means connected to said first time division multiplexed full duplex digital interface for storing and retrieving digitized signals.

16. The digital communication link of claim 15 wherein said means for storing and retrieving digitized signals includes storing and retrieving digitized audio.

17. The digital communication link of claim 11 wherein said means for serializing and deserializing signals is a time-division multiplexor/demultiplexor.

18. The digital communication link of claim 11 or 17 wherein the transmission and reception of signals between said first time division multiplexed full duplex digital interface and said second time division multiplexed full duplex digital interface is provided by a pulse code modulator/demodulator.

19. The digital communication link of claim 18, wherein said pulse code modulation signals are transmitted and formatted by Manchester II (biphase-L) format.

20. A Digital Serial Interface System comprising:

(a) a controller for a two-way radio;

(b) a radio frequency unit for a two-way radio;

(c) a time division multiplexed full duplex linking medium providing serial two-way communications for digital signals and digitized audio between said controller and said radio frequency unit;

(d) a first means for serializing and deserializing digital signals and digitized audio by time division multiplexing and pulse code modulation connected to said controller side of said full duplex linking medium; and

(e) a second means for serializing and deserializing digital signals and digitized audio by time division multiplexing and pulse code modulation connected to said radio frequency unit side of said time division multiplexed full duplex linking medium.

21. The Digital Serial Interface System of claim 20 wherein said first means and said second means for serializing and deserializing digital signals and digitized audio are operatively connected to said controller and said radio frequency unit.

22. The Digital Serial Interface System of claim 21 wherein said linking medium is a two or four path link.

23. The Digital Serial Interface System of claim 21 wherein said means for serializing and deserializing digital signals and digitized audio is a time-division multiplexor/demultiplexor.

24. The Digital Serial Interface System of claim 23 further comprising a first pulse code modulator/demodulator disposed on one end of said full duplex linking medium and a second pulse code modulator/demodulator disposed on the other end of said full duplex linking medium.

25. The Digital Serial Interface System of claim 23 wherein transmission and reception of digital signals and digitized audio between said controller and said radio frequency unit is accomplished by pulse code modulation and demodulation.

26. The Digital Serial Interface System of claim 25 wherein said pulse code modulation signals are transmitted and formatted by Manchester II (biphase-L) format.

27. A Digital Serial Interface System between a Control Unit and a Transceiver Unit of a two-way radio, said interface comprising:

(a) a linking medium;

(b) two interface blocks;

(c) one of said interface blocks associated with said Control Unit;

(d) one of said interface blocks associated with said Transceiver Unit;

(1) said interface block comprising;

(i) a digital controller;

(ii) a first digital input port for receiving a command channel word, said port having an input and an output;

(iii) a second digital port for receiving a status channel word, each said port having an input and an output;

(iv) a first command/status data switch, said switch having a first input, a second input and an output of said first input connected to said output of said first digital input port, said second input connected to said output of said second digital input port, said switch being set by said controller to whether a command channel word or a status channel word is to be transmitted in a frame being assembled;

(v) a first parallel to serial shift register, said register having an input and an output, said input connected to said output of said command/status data switch, said register loading said command channel word or said status channel word, as determined by said switch, into said register as ordered by said controller;

(vi) an audio analog-to-digital converter, said converter having an input and an output, said input receiving analog audio, said converter sampling said analog audio and providing a digital audio data word representing said sample, said digitized audio word being available at said converter'"'"'s output;

(vii) an audio serial-to-parallel shift register, said register having an input and an output, said digital controller moving said digitized audio word into said serial-to-parallel shift register upon completion of formation of said digitized audio word;

(viii) a second parallel-to-serial shift register, said register having a first input, a second input, and an output, said controller loading said digitized audio word from said audio serial-to-parallel shift register to said input of said second parallel-to-serial shift register.

(ix) a frame-former/Manchester encoder having an input and an output, said controller upon recognition that both said first parallel-to-serial shift register and said second parallel-to-serial shift register have been loaded loads both;

(1) said digitized audio word from said second parallel-to-serial shift register and (2) said channel word from said first parallel-to-serial shift register in serial form into said input of said frame-former/Manchester encoder, said, encoder forming the digital being assembled, said frame including said digitized audio word, said channel word, and a synch character, said encoder transmitting said assembled formed frame serially at said output of said encoder in biphase-L Manchester-II electrical format, said transmissions being synchronous;

(x) a transmitting line driver, said driver amplifying said output of said encoder to a level and electromagnetic spectrum frequency range suitable for transmission on said medium;

(xi) a line receiver, said receiver having an input and an output, said input connected to said medium, said receiver stripping noise from a biphase-L Manchester-2 signal received at said input from said medium, said receiver providing a data stream signal at a suitable level and electromagnetic spectrum frequency range at said output of said receiver;

(xii) a Manchester decoder having an input and an output, said decoder determining a Receive Clock signal from said data stream signal, said decoder determining whether a received frame is valid and thus containing (1) a received status channel word or received command channel word and (2) a digitized audio word in said received valid frame, said decoder transforming said suitable level suitable electromagnetic spectrum frequency range biphase-L Manchester II received signal at said input of said decoder into a suitable electrical form signal at said output of said decoder, said form signal containing said received digitized audio word and said received channel work;

(xiii) a first Receiver Serial-to-Parallel Shift Register, said register having an input and an output, said input connected to said output of said decoder, said register receiving and storing said received digitized audio word from said decoder, said controller causing such receipt and storage upon recognition that a valid frame has been received by said decoder;

(xiv) a second Receiver Serial-to-Parallel Shift Register, said register having an input and an output, said input connected to said output of said decoder, said register receiving and storing said receiver channel word from said decoder, said controller causing such receipt and storage upon recognition that a valid frame has been received by said decoder;

(xv) a Receiver command/status data switch, said decoder setting said switch to match whether said command channel word or said status channel word has been received at said decoder, said setting taking place upon receipt of said valid frame at said decoder;

(xvi) an Audio Parallel-to-Serial Shift Register, said register having an input and an output, said input connected to said output of said first Receiving Serial-to-Parallel Shift Register, said controller transferring the stored contents of said first Receiver Serial-to-Parallel Shift Register to said Audio Parallel-to-Serial Shift Register upon completion of receipt of all bits of said received digitized audio word to said First Receiver Serial-to-Parallel Shift Register;

(xvii) an Audio Digital-to-Analog Converter, said converter having an input and an output, said input connected to said output of said Audio Parallel to Serial Shift Register, said converter converting said received digitized audio word to an analog output, said controller causing said conversion to occur when said Audio Parallel-to-Serial Shift Register has received said received digitized audio word;

(xviii) a receiver command port, said port having an input and an output;

(xix) a receiver status port, said port having an input and an output, said receiver command port receiving and storing the stored contents of said Second Receiver Serial-to-Parallel Shift Register if said Receiver Command/Status data switch indicates a received command channel word, said receiver status port receiving and storing the stored contents of said Second Receiver Serial-to-Parallel Shift Register if said Receiver Command/Status Data Switch indicates a received status channel word, said controller causing such receipt at the appropriate command or status port upon completion of receipt of said received channel word at said Second Receiver Serial-to-Parallel Shift Register.

28. The invention of claim 27 wherein said pulse code modulation technique is Manchester II (biphase-L).

29. The invention of claim 27 wherein said communications linking medium is optical fiber.