Look ahead channel switching transceiver

• US 5,452,290 A
• Filed: 10/26/1992
• Issued: 09/19/1995
• Est. Priority Date: 10/26/1992
• Status: Expired due to Term

• Current Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Mihm, Thomas J. Jr.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Patel, Ajit
• Application Number:
  US05/452,290
• Time in Patent Office: 1,058 Days
• Field of Search: 370/95.1, 370/95.2, 370/95.3, 370/80, 370/81, 370/57, 370/50, 455/78, 455/34.1, 455/33.2, 455/156.1, 455/183.1, 455/76, 328/14
• US Class Current: 370/436
• CPC Class Codes: H04B 1/403 using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency
• CPC Class Codes: H04J 4/00 Combined time-division and frequency-division multiplex systems H04J13/00 takes precedence ; data transmission H04L5/26; telemetry G08C15/00

Abstract

A transceiver receives channel control commands which communicate predictions of upcoming frequency bands that might be used for communication or which communicate activations of upcoming frequency bands and time units which will be used for communication. The transceiver includes a plurality of synthesizers which can be switched to control the frequencies at which a receiver and transmitter operate. When predictions are received, frequency IDs associated therewith are used in programming new frequencies into non-activated ones of the synthesizers. When each activation is received, a memory structure is programmed to identify one of the synthesizers, to record a frequency for programming into the identified synthesizer, and to record timing data describing when to program the identified synthesizer and when to activate the identified synthesizer. The memory structure is used to control the programming and switching of synthesizers which drive the receiver and the transmitter.

Claims

1. A method of communicating data using a variable bandwidth communication channel, said method comprising the steps of:

receiving, from a communication network controller at a transceiver in a receive time unit, a channel control command, said channel control command identifying a plurality of time units available for use in communicating said data;

communicating by said transceiver portions of said data during said identified time units, wherein said channel control command associates a frequency with each of said identified time units, and said transceiver communicates said portions of said data at said frequency associated with each of said identified time units;

programming a first synthesizer to generate a first oscillation signal corresponding to a first frequency associated with each of said time units identified by said channel control command; and

programming a second synthesizer to generate a second oscillation signal corresponding to a second frequency associated with each of said time units identified by said channel control command.

2. A method as claimed in claim 1 wherein said method additionally comprises the steps of:

recognizing by said transceiver a first switching event so that, after said first switching event, said communicating step communicates at a frequency which is defined by said first oscillation signal; and

recognizing by said transceiver a second switching event so that, after said second switching event, said communicating step communicates at a frequency which is defined by said second oscillation signal, said first and second switching events comprising an instruction to said transceiver to activate a new frequency.

3. A method of controlling a transceiver having a first synthesizer and a second synthesizer, said method permitting rapid switching between channels, and said method comprising the steps of:

receiving a channel control command from a communication network controller at a transceiver;

programming said first synthesizer to generate a first oscillation signal corresponding to a channel having a frequency which is responsive to said channel control command;

communicating, by said transceiver after said programming step, over a channel which is defined by a second oscillation signal generated by said second synthesizer;

recognizing a switching event, said switching event being an instruction to said transceiver to activate the frequency programmed by said first synthesizer; and

communicating by said transceiver, after said switching event, over said channel which is defined by said first oscillation signal, wherein

said channel control command identifies a plurality of frequencies; and

said programming step programs a plurality of synthesizers, including said first synthesizer, to generate a corresponding plurality of oscillation signals, including said first oscillation signal.

4. A method as claimed in claim 3 wherein said recognizing step comprises the step of selecting said first oscillating signal from said plurality of oscillation signals.

5. A method as claimed in claim 3 wherein said recognizing step comprises the step of receiving a second channel control command which identifies said first oscillation signal.

6. A method as claimed in claim 3 wherein:

said channel control command identifies a time unit available for use in communicating data; and

said recognizing step comprises the step of identifying said time unit.

7. A method of controlling a transceiver having a first synthesizer and a second synthesizer, said method permitting rapid switching between channels, and said method comprising the steps of:

receiving a channel control command from a communication network controller at a transceiver;

programming said first synthesizer to generate a first oscillation signal corresponding to a channel having a frequency which is responsive to said channel control command;

communicating, by said transceiver after said programming step, over a channel which is defined by a second oscillation signal generated by said second synthesizer;

recognizing a switching event, said switching event being an instruction to said transceiver to activate take frequency programmed by said first synthesizer;

; and

communicating by said transceiver, after said switching event, over said channel which is defined by said first oscillation signal,

said channel control command identifies a first frequency corresponding to said first oscillation signal, a first time unit associated with said first frequency, a second frequency, and a second time unit associated with said second frequency;

said recognizing step comprises the step of identifying said first time unit; and

said method additionally comprises the step of programming, after said recognizing step, said second synthesizer to generate a third oscillation signal which corresponds to said second frequency.

8. A method as claimed in claim 7 additionally comprising the steps of:

identifying said second time unit; and

communicating, after said second time unit, over a channel which is defined by said third oscillation signal.

9. A method of operating a transceiver for communication over a variable bandwidth communication channel, said transceiver having a first synthesizer and a second synthesizer, said method permitting rapid switching between channels, and said method comprising the steps of:

(a) programming said first synthesizer to oscillate at a first frequency;

(b) transmitting to a communication network controller by said transceiver a first communication at said first frequency;

(c) receiving from said communication network controller at said transceiver a channel control command which specifies a second frequency, said channel control command identifying a time unit available for use in transmitting data at said second frequency;

(d) programming said second synthesizer to oscillate at said second frequency in response to laid channel control command;

(e) transmitting by said transceiver a second communication at said second frequency; and

(f) recognizing a switching event so that said step (e) is performed in response to said switching event, said switching event being an instruction to said transceiver to activate said second frequency during the occurrence of said identified time unit.

10. A method of operating a transceiver having a first synthesizer and a second synthesizer, said method permitting rapid switching between channels, and said method comprising the steps of:

(a) programming said first synthesizer to oscillate at a first frequency;

(b) transmitting to a communication network controller by said transceiver a first communication at said first frequency;

(c) receiving from said communication network controller at said transceiver a channel control command which specifies a second frequency;

(d) programming said second synthesizer to oscillate at said second frequency in response to said channel control command; and

(e) transmitting by said transceiver a second communication at said second frequency,

said channel control command identifies a plurality of frequencies including said second frequency; and

said step (d) programs a plurality of synthesizers, including said second synthesizer, to oscillate at a corresponding plurality of frequencies, including said second frequency.

11. A method as claimed in claim 10 additionally comprising the step of selecting said second frequency from said plurality of frequencies.

12. A method as claimed in claim 11 wherein said selecting step comprises the step of receiving a second channel control command which identifies said second frequency.

13. A transceiver which is quickly switchable between channels, said transceiver comprising:

a first synthesizer having a control input and an oscillator output;

a second synthesizer having a control input and an oscillator output;

a transmitter having an oscillator input;

a switch having first and second input ports coupled to said first and second synthesizer oscillator outputs, respectively, having an output port coupled to said oscillator input of said transmitter, and having a control input;

a receiver having a baseband output for outputting data; and

a controller having an input coupled to said receiver baseband output and having at least one data output coupled to said first and second synthesizer and switch control inputs,

said controller is further configured to monitor said data received from said receiver baseband output and to program said second synthesizer in response to said received data.

14. A transceiver as claimed in claim 13 wherein said controller is further configured to recognize a switching event and to control said switch so that said second synthesizer drives said transmitter when said switching event occurs, said switching event being an instruction to said transceiver to activate a new frequency.

15. A transceiver as claimed in claim 14 wherein

said controller is further configured to identify an activation channel control command obtained from said receiver baseband output as said switching event.

16. A transceiver as claimed in claim 14 wherein:

said received data additionally specifies a time unit available for use in transmitting from said transmitter; and

said controller is further configured to identify said specified time unit as said switching event.

17. A transceiver as claimed in claim 13 wherein said controller is configured so that said first synthesizer drives said transmitter immediately after said controller programs said second synthesizer to generate a new frequency at said second synthesizer oscillator output.

18. A method for communicating using up to L different frequency channels during some of T time units where L and T are less than 5000, comprising the steps of:

providing M frequency synthesizers for controlling up to L carrier frequencies for the L different channels, where M<

L and M is a positive integer;

providing up to M-1 of L assignments for up to M-1 of the frequency synthesizers, each of said assignments being associated with a predicted carrier frequency and being directed toward future time units;

pre-setting up to M-1 of M frequency synthesizers to provide the M-1 of L predicted carrier frequencies;

receiving a channel control command that identifies said predicted carrier frequency and identifies a first time segment; and

thereafter activating at least one of the L different frequency channels using one of said M frequency synthesizers pre-set in said presetting step during said first time segment, wherein said at least one of said L different frequency channels corresponds to said predicted carrier frequency, and wherein the activating step is performed in response to receipt of said channel control command.

19. A method as claimed in claim 18 further comprising activating another of the L different frequency channels using another of said M frequency synthesizers pre-set in said pre-setting step during a second time segment.

20. A transceiver for switching between any of L different frequency communication channels L being less than 5000, in a first time period, comprising:

M frequency synthesizer means for generating any of the L different frequencies, said frequency synthesizer means having frequency setting time periods, wherein said frequency setting time periods are greater than said first time period, and where M<

L and M is a positive integer;

means, coupled to the synthesizer means, for pre-setting up to M-1 of the frequency synthesizer means for up to M-1 anticipated communication channel frequencies prior to their use for communication;

means, coupled to said means for pre-setting for receiving a channel control command that identifies a first time segment and identifies one of said anticipated communication channel frequencies that is to be activated during said first time segment, said frequency being one of said L different frequencies; and

switching means, coupled to the synthesizer means, for activating one of the preset frequency synthesizer means during said first time segment for use in a predetermined communications channel, said one of the preset frequency synthesizer means generating said anticipated communication channel frequency identified by said channel control command.

21. A transceiver as claimed in claim 20, further comprising, monitoring means, coupled to the presetting and switching means, for determining which communication channels are likely to be required to operate in which frequencies and for instructing the pre-setting means on the frequencies to which the synthesizers should be preset.

22. A transceiver for switching between any of L different frequency communication channels L being less than 5000, in a first time period, comprising:

M frequency synthesizer means for generating any of the L different frequencies, said frequency synthesizer means having frequency setting time periods, wherein said frequency setting time periods are greater than said first time period, and where M<

L and M is a positive integer;

means, coupled to the synthesizer means, for pre-setting up to M-1 of the frequency synthesizer means for up to M-1 anticipated communication channel frequencies prior to their use for communication;

switching means, coupled to the synthesizer means, for activating one of the preset frequency synthesizer means for use in a predetermined communications channel;

monitoring means, coupled to the pre-setting and switching means, for determining which communication channels are likely to be required to operate in which frequencies and for instructing the presetting means on the frequencies to which the synthesizers should be preset; and

memory means, coupled to said monitoring means, synthesizer means, presetting means, and switching means, for storing instructions for presetting and activating the synthesizer means.