Adaptive power control for a spread spectrum communications system and method

• US 5,299,226 A
• Filed: 11/19/1991
• Issued: 03/29/1994
• Est. Priority Date: 11/16/1990
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Primary Examiner(s): Swann, Tod R.
• Application Number:
  US07/792,869
• Time in Patent Office: 861 Days
• Field of Search: 380/34, 380/39, 380/40, 375/1, 375/102, 455/33.1, 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: H04B 1/709 Correlator structure
• 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 first spread-spectrum signal. A mobile station has an automatic-gain-control circuit for generating an AGC-output signal, from a received signal. The received signal includes the first spread-spectrum signal and an interfering signal. The mobile station also has a correlator for despreading the AGC-output signal, a power-measurement circuit responsive to processing the received signal with the despread AGC-output signal for generating a received-power level, a comparator coupled to the power-measurement circuit for generating a comparison signal by comparing the received-power level to a threshold level, a transmitter for transmitting a second spread-spectrum signal, an antenna, and a variable-gain device responsive to the comparison signal for adjusting a transmitter-power level of the second 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, wherein a base station transmits a first spread-spectrum signal, said mobile station comprising:

AGC means responsive to a received signal, wherein the received signal includes the first spread-spectrum signal and an interfering signal, for generating an AGC-output signal;

correlator means for despreading the AGC-output signal;

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes means for multiplying the received signal with the depread AGC-output signal, for generating a received-power level;

comparator means for generating a comparison signal by comparing the received-power level to a threshold level;

transmitter means for transmitting a second spread-spectrum signal;

an antenna; and

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

2. 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, wherein a base station transmits a first spread-spectrum signal, said mobile station comprising:

AGC means responsive to a received signal, wherein the received signal includes the first spread-spectrum signal and an interfering signal, for generating an AGC-output signal;

correlator means for despreading the AGC-output signal;

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes logarithmic means for adding the received signal with the depread AGC-output signal, for generating a received power level;

comparator means for generating a comparison signal by comparing the received-power level to a threshold level;

transmitter means for transmitting a second spread-spectrum signal;

an antenna; and

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

3. An apparatus for determining a received-power level of a spread-spectrum signal, when a received signal includes the spread-spectrum signal and an interfering signal, comprising:

AGC means responsive to the received signal for generating an AGC-output signal;

correlator means, including a differential amplifier, for despreading the AGC-output signal; and

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes means for multiplying the received signal with the despread AGC-output signal, for generating a received-power level.

4. An apparatus for determining a received-power level of a spread-spectrum signal, when a received signal includes the spread-spectrum signal and an interfering signal, comprising:

AGC means responsive to the received signal for generating an AGC-output signal;

correlator means, including a differential amplifier, for despreading the AGC-output signal; and

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes logarithmic means for adding the received signal with the despread AGC-output signal, for generating a received-power level.

5. 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, wherein a base station transmits a first spread-spectrum signal and an APC-data signal, said mobile station comprising:

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

AGC means responsive to a received signal, wherein the received signal includes the first spread-spectrum signal and an interfering signal, for generating an AGC-output signal;

correlator means for despreading the AGC-output signal;

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes means for multiplying the received signal with the despread AGC-output signal, for generating a received-power level;

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

transmitter means for transmitting a second spread-spectrum signal;

an antenna; and

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

6. 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, wherein a base station transmits a first spread-spectrum signal and an APC-data signal, said mobile station comprising:

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

AGC means responsive to a received signal, wherein the received signal includes the first spread-spectrum signal and an interfering signal, for generating an AGC-output signal;

correlator means for despreading the AGC-output signal;

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes logarithmic means for adding the received signal with the despread AGC-output signal, for generating a received-power level;

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

transmitter means for transmitting a second spread-spectrum signal;

an antenna; and

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

7. An apparatus for determining a received-power level of a spread-spectrum signal, when a received signal includes the spread-spectrum signal and an interfering signal, comprising:

AGC means responsive to the received signal for generating an AGC-output signal;

correlator means for despreading the AGC-output signal; and

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes means for multiplying the received signal with the despread AGC-output signal, for generating a received-power level.

8. An apparatus for determining a received-power level of a spread-spectrum signal, when a received signal includes the spread-spectrum signal and an interfering signal, comprising:

AGC means responsive to the received signal for generating an AGC-output signal;

correlator means for despreading the AGC-output signal; and

power means responsive to processing the received signal with the despread AGC-output signal, wherein said power means includes logarithmic means for adding the received signal with the despread AGC-output signal, for generating a received-power level.