Ring signal generator

• US 6,243,399 B1
• Filed: 01/27/1997
• Issued: 06/05/2001
• Est. Priority Date: 07/21/1994
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Kaewell, John, Smith, Joseph Mark
• Primary Examiner(s): TON, DANG T
• Application Number:
  US08/788,411
• Time in Patent Office: 1,590 Days
• Field of Search: 370/311, 370/525, 370/526, 370/480, 370/343, 370/344, 370/503, 370/276, 370/280, 370/281, 370/294, 370/295, 370/321, 370/337, 370/338, 370/347, 370/350, 370/442, 370/518, 370/520, 370/403, 370/404, 370/405, 370/499, 370/498, 379/373, 379/351, 379/379, 379/252, 379/253, 379/382, 379/418, 455/343, 375/261, 375/297, 375/298, 375/354, 375/355, 375/356, 375/357, 375/359, 375/362, 375/364
• US Class Current: 370/525
• CPC Class Codes: H04B 1/036 Cooling arrangements
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04M 1/725 Cordless telephones user interfaces specially adapted therefor H04M1/724
• CPC Class Codes: H04M 1/73 Battery saving arrangements
• CPC Class Codes: H04M 19/02 providing ringing current or supervisory tones, e.g. dialling tone or busy tone
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 52/0283 with sequential power up or power down of successive circuit blocks, e.g. switching on the local oscillator before RF or mixer stages
• CPC Class Codes: H04W 52/029 reducing the clock frequency of the controller
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A subscriber unit of a time division multiple access (TDMA) radiotelephone system is, from a power consumption standpoint, reconfigured in each time slot of a TDMA frame to a power consumption tessellation in which subscriber unit circuit components not needed for communication signal processing in that time slot are powered down, and other components are powered up.

Some circuit components are powered down by switching their power supply circuits. In order to minimize the extent of circuitry that must be provided to distribute power consumption control signals, other techniques (which utilize circuitry provided for other purposes), such as clock frequency control or power down commands, also are utilized to modify controlled circuit component power consumption without actually controlling power supply circuits. Loop connection length between the subscriber unit and the subscriber'"'"'s telephone set, or other terminal equipment, is limited to a length which is much less than the length of a radio link on which the subscriber unit operates. Programmable ring frequency logic controls the frequency of a ringing signal generator, and a high frequency ring control signal is switched on and off in the cadence of ringing operation. Also an expansion header is provided to enable serving plural subscriber loop circuits with the same radio equipment for reducing per line power consumption.

Claims

1. A ringing signal generator comprising:

means for registering a data word representing a selectable one of a plurality of predetermined ringing signal frequencies;

means for supplying a clocking signal of a predetermined frequency which is much higher than any of said predetermined ringing signal frequencies;

means, responsive to said data word and said clock signal, for generating a low amplitude signal at said selectable one frequency;

means for amplifying said clock signal to produce an intermediate signal having both positive polarity and negative polarity portions in each frequency cycle;

means for separately half-wave rectifying each of said positive and negative polarity portions;

means, responsive to said low amplitude signal, for alternately sampling said separately rectified positive and negative polarity portions;

means for low pass filtering an output of said sampling means to produce a ringing signal at a larger amplitude and at said selectable one frequency;

means for providing a gating signal of average frequency which is much less than the frequency of said selectable one frequency and having an on-time/off-time duty cycle defining a predetermined ringing signal cadence;

means, responsive to said gating signal on-time, for selectively coupling said clock signal to said amplifying means and selectively coupling said low amplitude signal to said alternately sampling means during only said on-time for thereby periodically powering down said ringing signal generator during said off-time of said gating signal.

2. A ringing signal generator according to claim 1, wherein said intermediate signal has an amplitude larger than the amplitude of said selectable one frequency signal and having a frequency much greater than the frequency of said selectable one frequency.

3. Apparatus for generating a ring signal having a desired frequency, said apparatus comprising:

means, including a counter, for receiving a digital value corresponding to said desired frequency and, responsive thereto, for generating a ring frequency signal having a frequency corresponding to said desired frequency of said ring signal, wherein said ring frequency signal is generated by counting on said counter from said digital value and counting to a fixed value;

means for generating a ring control signal for indicating a cadence of said ring signal; and

means for generating said ring signal based on said ring frequency signal and for cycling said ring signal on and off based on said ring control signal.

4. Apparatus of claim 3, further comprising means for applying a clock signal to a) actuate said counter and b) sample an output signal generated by said counter.

5. Apparatus of claim 3, further comprising means for generating one of a plurality of ring signal values and for transmitting said one of said plurality of ring signal values to said means for generating said ring frequency signal as said digital value, wherein each of said ring signal values corresponds to a respective frequency of a plurality of frequencies of said ring signal, and wherein any of said plurality of frequencies is said desired frequency.

6. Apparatus of claim 3, wherein said means for generating said ring signal generates said ring signal at a higher voltage than respective voltages of said ring frequency signal and said ring control signal.

7. Apparatus of claim 3, further comprising means for rectifying said ring frequency signal and for sampling said rectified ring frequency signal based on said ring control signal to generate said ring signal.

8. Apparatus of claim 3, wherein said ring frequency signal includes a plurality of out pulses each separated by a ring frequency zero crossing further comprising means for gating off each of said outpulses adjacent to each ring frequency zero crossing to generate said ring signal with at least three signal levels.

17. Apparatus of claim 3 wherein said ring signal generating means comprises:

means for amplifying a clock signal; and

means, responsive to said cycled ring frequency signal, for sampling said amplified clock signal to produce said ring signal.

18. Apparatus of claim 17 further comprising:

means for selectively coupling said clock signal to said amplifying means only during on portions of said cadence; and

means for selectively coupling, in response to said ring control signal, said ring frequency signal to said sampling means to generate said cycled ring frequency signal.

9. Apparatus for generating a ring signal having a desired frequency, said apparatus comprising:

means, for receiving a digital value corresponding to said desired frequency and, responsive thereto, for generating a ring frequency signal having a frequency corresponding to said desired frequency of a ringing signal;

means for generating a ring control signal for indicating a cadence having on portions and off portions of said ring signal;

means for selectively coupling an input signal to an amplifying means only during the on portions of said ring control signal cadence;

said amplifying means for amplifying said selectively coupled input signal;

means for selectively coupling said ring frequency signal to a sampling means only during the on portions of said ring control signal cadence; and

said sampling means for sampling said amplified input signal in response to said selectively coupled ring frequency signal to produce said ring signal at said desired frequency.

10. Apparatus for generating a ring signal comprising:

means for generating a ring frequency signal at a desired frequency;

means for receiving said ring frequency signal and combining said ring frequency signal with a ring control signal to generate a first intermediate signal having a plurality of outpulses associated with said ring control signal each separated by a ring frequency zero crossing, wherein each of said outpulses have gated off adjacent to each ring frequency zero crossing;

means for receiving an input signal and sampling said input signal in response to said ring control signal to generate a second intermediate signal having said plurality of outpulses associated with said ring control signal; and

means for amplifying said second intermediate signal and sampling said first intermediate signal in response to said second intermediate frequency signal to generate said ring signal having at least three signal levels at said desired frequency.

11. Apparatus for generating a ring signal according to claim 10, wherein said means for generating said ring frequency signal includes means for receiving a digital value corresponding to said desired frequency and, responsive thereto, for generating said rings frequency signal having a frequency corresponding to said desired frequency .

12. Apparatus of claim 11, wherein said means for generating said ring frequency signal includes a counter for counting from said digital value to a fixed value to generate said ring, frequency signal.

13. Apparatus of claim 12, further comprising means for applying a clock signal to a) actuate said counter and b) sample an output signal generated by said counter.

14. Apparatus of claim 11, further comprising means for generating one of a plurality of ring signal values and for transmitting said one of said plurality of ring signal values to said means for generating said ring frequency signal as said digital value, wherein each of said ring signal values corresponds to a respective frequency of a plurality of frequencies of said ring signal, and wherein any of said plurality of frequencies is said desired frequency.

15. Apparatus of claim 10, further comprising means for generating said ring control signal for indicating a cadence of said ring signal, wherein said means for generating said ring signal generates said ring signal at a higher voltage than respective voltages of said ring frequency signal and said ring control signal.

16. Apparatus of claim 15, wherein said amplifying and sampling means further comprises means for rectifying said second intermediate signal and for sampling said rectified second intermediate signal based on said first intermediate signal to generate said ring signal.