Adaptive power control for a spread spectrum transmitter

• US 5,093,840 A
• Filed: 11/16/1990
• Issued: 03/03/1992
• Est. Priority Date: 11/16/1990
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: SCS Mobilecom, Inc (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): SWANN, TOD R
• Application Number:
  US07/614,816
• Time in Patent Office: 473 Days
• Field of Search: 375/1, 375/102, 380/33, 380/34, 380/39, 380/40, 455/33, 455/59, 455/61, 455/103, 455/191, 455/212, 455/213, 455/224, 455/225, 379/59, 379/63
• US Class Current: 375/130
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

An apparatus for adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network using spread-spectrum modulation. A base station transmits a generic spread-spectrum signal and an APC-data signal. A mobile station has an acquisition circuit for acquiring and decoding the generic spread-spectrum signal, a detector for detecting a received power level of the generic spread-spectrum signal, a decoder for decoding the APC-data signal as a threshold, a differential amplifier for generating a comparison signal by comparing the received power level to the threshold, a transmitter for transmitting a transmitter spread-spectrum signal, an antenna, and a variable-gain device responsive to the comparison signal indicating an increase or decrease for adjusting a transmitter-power level of the transmitter spread-spectrum signal.

Claims

1. An apparatus for adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network using spread-spectrum modulation, comprising:

a base station for transmitting a generic spread-spectrum signal and an APC-data signal;

a multiplicity of said mobile stations, each mobile station having

an acquisition circuit for acquiring and decoding the generic spread-spectrum signal;

a detector coupled to said acquisition circuit for detecting a received power level of the generic spread-spectrum signal;

a decoder coupled to said acquisition circuit for decoding the APC-data signal as a threshold;

a differential amplifier coupled to said detector and said decoder for generating a comparison signal by comparing the received power level to said threshold;

a transmitter for transmitting a transmitter spread-spectrum signal;

an antenna coupled to said transmitter; and

a variable-gain device coupled to said differential amplifier and between said transmitter and said antenna, responsive to said comparison signal indicating an increase or decrease for adjusting a transmitter-power level of the transmitter spread-spectrum signal from said transmitter.

2. An apparatus for adaptive-power control of a spread-spectrum transmitter of a plurality of mobile stations operating in a cellular-communications network using spread-spectrum modulation, wherein a base station transmits a generic spread-spectrum signal and an APC-data signal, each mobile station comprising:

acquisition means for acquiring and decoding the generic spread-spectrum signal;

detector means for detecting a received power level of the generic spread-spectrum signal;

decoder means for decoding the APC-data signal as a threshold;

differential means for generating a comparison signal by comparing the received power level to said threshold;

transmitter means for transmitting a transmitter spread-spectrum signal;

an antenna; and

variable-gain means responsive to said comparison signal for adjusting a transmitter-power level of the transmitter spread-spectrum signal from said transmitter.

3. The apparatus as set forth in claim 2 wherein said acquisition means includes:

a first chip-code generator;

a first bandpass filter; and

a first product device coupled to said first chip code generator and said bandpass filter.

4. The apparatus as set forth in claim 2 wherein said differential means includes:

a differential amplifier.

5. The apparatus as set forth in claim 2 wherein said decoder means includes:

a data demodulator.

6. The apparatus as set forth in claim 2 wherein said variable-gain means includes:

a variable-gain attenuator.

7. The apparatus as set forth in claim 2 wherein said variable-gain means includes:

a variable-gain amplifier.

8. A method for adaptive-power control of a spread-spectrum transmitter of a plurality of mobile stations operating in a cellular-communication network using spread-spectrum modulating, wherein a base station transmits a generic spread-spectrum signal and an APC-data signal, said method comprising the steps at each mobile station, of:

acquiring and decoding the generic spread-spectrum signal;

detecting a received power level of the generic spread-spectrum signal;

decoding the APC-data signal as a threshold;

generating a comparison signal by comparing the received power level to said threshold;

transmitting a transmitter spread-spectrum signal; and

adjusting a transmitter-power level of the transmitter spread-spectrum signal from said transmitter using said comparison signal.