GAIN CONTROL METHOD AND APPARATUS
First Claim
1. A gain controller comprising:
- a first delay circuit configured to receive an in-phase (I) signal and output a delayed I signal;
a second delay circuit configured to receive a quadrature (Q) signal and output a delayed Q signal;
a normalization circuit for adjusting the gain of the received I and Q signals on a block-by-block basis as a function of averaged combined signal strength measurements of the received I and Q signals;
a first multiplier having a first input electrically coupled to an output of the first delay circuit, and a second input electrically coupled to an output of the normalization circuit used to adjust the gain of the delayed I signal, wherein the first multiplier outputs a value substantially equal to the delayed I signal divided by the averaged combined signal strength of the received I and Q signals; and
a second multiplier having a first input electrically coupled to an output of the second delay circuit, and a second input electrically coupled to an output of the normalization circuit used to adjust the gain of the delayed Q signal, wherein the second multiplier outputs a value substantially equal to the delayed Q signal divided by the averaged combined signal strength of the received I and Q signals.
0 Assignments
0 Petitions
Accused Products
Abstract
An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.
17 Citations
11 Claims
-
1. A gain controller comprising:
-
a first delay circuit configured to receive an in-phase (I) signal and output a delayed I signal; a second delay circuit configured to receive a quadrature (Q) signal and output a delayed Q signal; a normalization circuit for adjusting the gain of the received I and Q signals on a block-by-block basis as a function of averaged combined signal strength measurements of the received I and Q signals; a first multiplier having a first input electrically coupled to an output of the first delay circuit, and a second input electrically coupled to an output of the normalization circuit used to adjust the gain of the delayed I signal, wherein the first multiplier outputs a value substantially equal to the delayed I signal divided by the averaged combined signal strength of the received I and Q signals; and a second multiplier having a first input electrically coupled to an output of the second delay circuit, and a second input electrically coupled to an output of the normalization circuit used to adjust the gain of the delayed Q signal, wherein the second multiplier outputs a value substantially equal to the delayed Q signal divided by the averaged combined signal strength of the received I and Q signals. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A gain control method comprising:
-
receiving an in-phase (I) signal; receiving a quadrature (Q) signal; adjusting the gain of the received I and Q signals on a block-by-block basis as a function of averaged combined power measurements of the received I and Q signals; delaying the received I signal to generate a delayed I signal; delaying the received Q signal to generate a delayed Q signal; dividing the delayed I signal by the averaged combined signal strength of the received I and Q signals; and dividing the delayed Q signal by the averaged combined signal strength of the received I and Q signals. - View Dependent Claims (7, 8, 9, 10, 11)
-
Specification