System and method for reducing interference generated by a CDMA communications device

• US 6,205,190 B1
• Filed: 04/29/1996
• Issued: 03/20/2001
• Est. Priority Date: 04/29/1996
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gilhousen, Klein S., Blakeney, Robert D. II, Antonio, Franklin, Quick, Roy F.
• Primary Examiner(s): Tsang, Fan
• Assistant Examiner(s): Tran, Congvan
• Application Number:
  US08/639,572
• Time in Patent Office: 1,786 Days
• Field of Search: 375/200, 375/205, 375/254, 375/278, 375/285, 375/296, 375/346, 370/320, 370/335, 370/310, 370/392, 370/318, 370/333, 370/341
• US Class Current: 375/346
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10

Abstract

A system and method for reducing the interference experienced by sensitive electronic devices, such as hearing aids, operative in the vicinity of CDMA user communication devices. A transmitter of the communications device is configured to transmit signal power substantially continuously at a full rate power level irrespective of the variable data rate at which the transmitter would otherwise be operative. In a first embodiment, a variable rate vocoder within the transmitter is directed to perform full-rate vocoding, irrespective of an instantaneous level of user speech. In a second embodiment, a microprocessor builds full-rate frames using repeated versions of code symbols generated by the vocoder. In a third embodiment, the microprocessor builds full rate frames by generating signaling bits of a predetermined pattern to pad otherwise non-full frames.

Claims

1. A system for reducing interference generated by a communication device which nominally transmits data at a variable rate and which nominally varies transmit power in response to said variable rate, said system comprising:

means for directing said communication device to continuously transmit RF energy at a full rate power level irrespective of said variable rate; and

means, in said communication device and responsive to said means for directing, for transmitting RF energy continuously at said full rate power level irrespective of said variable rate, whereby said interference is reduced proximate said communication device due to continuous transmission thereby at said full rate power level;

wherein said communication device nominally transmits non-full frames of data containing a variable number of bits in response to said variable rate, and wherein said means for transmitting comprises;

a controller for generating full frames of data containing a fixed number of bits irrespective of said variable rate; and

a transmitter for transmitting said full frames of data at said full-rate power level; and

wherein said communication device nominally distributes said variable number of bits pseudo-randomly in said non-full frames of data, and wherein said full frames of data generated by said controller contain a variable number of padding bits having a predetermined pattern.

2. The system of claim 1 wherein said controller generates a reduced interference mode intention signal, and wherein said transmitter transmits said reduced interference mode intention signal to a base station associated with said communication device.

3. The system of claim 1 wherein each of said padding bits has a logical zero value.

4. A method for reducing interference generated by a communication device which nominally transmits data at a variable rate and which nominally varies transmit power in response to said variable rate, said method comprising the steps of:

directing said communication device to continuously transmit RF energy at a full rate power level irrespective of said variable rate; and

transmitting, from said communication device and in response to said directing step, RF energy continuously at said full rate power level irrespective of said variable rate, whereby said interference is reduced proximate said communication device due to continuous transmission thereby at said full rate power level;

wherein said communication device nominally transmits non-full frames of data containing a variable number of bits in response to said variable rate, and wherein said transmitting step further comprises the steps of;

generating full frames of data containing a fixed number of bits irrespective of said variable rate; and

transmitting said full frames of data at said full-rate power level; and

wherein said communication device nominally distributes said variable number of bits pseudo-randomly in said non-full frames of data, and wherein said full frames of data generated by said controller contain a variable number of padding bits having a predetermined pattern.

5. The method of claim 4 further comprising the steps of:

generating a reduced interference mode intention signal; and

transmitting said reduced interference mode intention signal to a base station associated with said communication device.

6. The system of claim 4 wherein each of said padding bits has a logical zero value.

7. A communication device which nominally transmits data at a variable rate and which nominally varies transmit power in response to said variable rate, said system comprising:

a transmitter; and

a controller for directing said transmitter to transmit RF energy continuously at a full rate power level irrespective of said variable rate, whereby said interference is reduced proximate said communication device due to continuous transmission thereby at said full rate power level;

wherein said communication device nominally transmits non-full frames of data containing a variable number of bits in response to said variable rate, and wherein said controller generates full frames of data containing a fixed number of bits irrespective of said variable rate and wherein said transmitter transmits said full frames of data at said full-rate power level; and

wherein said communication device nominally distributes said variable number of bits pseudo-randomly in said non-full frames of data, and wherein said full frames of data generated by said controller contain a variable number of padding bits having a predetermined pattern.

8. The communication device of claim 7 wherein said controller generates a reduced interference mode intention signal, and wherein said transmitter transmits said reduced interference mode intention signal to a base station associated with said communication device.

9. The communication device of claim 7 wherein each of said padding bits has a logical zero value.

10. A base station in a communication system in which a plurality of communication devices nominally transmit data at a variable rate and which nominally vary transmit power in response to said variable rate, said base station comprising:

means for directing a first of said plurality of communication devices to continuously transmit RF energy at a full rate power level irrespective of said variable rate, whereby interference is reduced proximate said first communication device due to continuous transmission thereby; and

means for receiving said RF energy continuously transmitted by said first communication device;

means for determining whether one of said plurality of communication devices is continuously transmitting RF energy at a full rate power level irrespective of said variable rate;

wherein said means for determining examines a first N bits of signaling traffic of a frame transmitted by said one of said plurality of communication devices to determine whether said one of said plurality of communication devices is continuously transmitting RF energy.

11. The base station of claim 10 wherein said means for determining determines that said one of said plurality of communication devices is continuously transmitting RF energy if said first N bits of signaling traffic matches a predetermined bit pattern.

12. The base station of claim 10 wherein said predetermined bit pattern is all zero bits.

13. A method for reducing interference generated by a first of a plurality of communication devices which nominally transmit data at a variable rate and which nominally vary transmit power in response to said variable rate, said method comprising the steps of:

directing a first of said plurality of communication devices to continuously transmit RF energy at a full rate power level irrespective of said variable rate, whereby interference is reduced proximate said first communication device due to continuous transmission thereby;

receiving said RF energy continuously transmitted by said first communication device; and

determining whether one of said plurality of communication devices is continuously transmitting RF energy at a full rate power level irrespective of said variable rate;

wherein said determining step further comprises the step of examining a first N bits of signaling traffic of a frame transmitted by said one of said plurality of communication devices to determine whether said one of said plurality of communication devices is continuously transmitting RF energy.

14. The method of claim 13 wherein said determining step further comprises the step of determining that said one of said plurality of communication devices is continuously transmitting RF energy if said first N bits of signaling traffic matches a predetermined bit pattern.

15. The base station of claim 13 wherein said predetermined bit pattern is all zero bits.