Digital automatic gain control
AssigneeQUALCOMM Incorporated
InventorDaniel F. Filipovic
Life of this patent
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Abstract
A wireless communication device (WCD) implements an improved architecture for performing automatic gain control (AGC). For example, a WCD including a wireless receiver and a modem may incorporate a digital variable gain amplifier (DVGA) and an automatic gain control (AGC) unit that have the improved architecture. In particular, the architecture of the DVGA and AGC unit may be simplified and improved specifically for handing signals modulated according to a wireless networking standard such as one of the IEEE 802.11 standards.
Claims36
A method comprising:
- multiplying an M-bit baseband sample of an RF signal by an N-bit gain factor to generate a product having M+N bits;
- shifting the M-bit baseband sample by N bits to generate a shifted value having M+N bits;
- and
- generating an output by selecting a subset of M+N+1 bits of a sum of the product and the shifted value.
A method comprising:
- measuring power levels of baseband samples of an RF signal;
- accumulating differences between the measured power levels and a set point;
- adjusting a gain factor as a function of the accumulation;
- and
- applying the adjusted gain factor to scale the baseband samples.
A wireless communication device comprising:
- a variable gain amplifier including:
- a multiplier to multiply an M-bit baseband sample of an RF signal by an N-bit gain factor to generate a product having M+N bits,
- a shift register to shift the M-bit baseband sample by N bits to generate a shifted value having M+N bits, and
- a bit selector to generate an output by selecting at least a subset of M+N+1 bits of a sum of the product and the shifted value;
- and
- a demodulation unit to demodulate the output.
A wireless communication device comprising:
- an automatic gain control unit that measures a power level of baseband samples of an RF signal and accumulates differences between the measured power levels and a set point;
- and
- a digital variable gain amplifier that adjusts a gain factor as a function of the accumulation and applies the adjusted gain factor to scale the baseband samples.
A variable gain amplifier comprising:
- a multiplier to multiply an M-bit baseband sample of an RF signal by an N-bit gain factor to generate a product having M+N bits;
- a shift register to shift the M-bit baseband sample by N bits to generate a shifted value having M+N bits;
- and
- a bit selector to generate an output by selecting at least a subset of M+N+1 bits of a sum of the product and the shifted value.
An integrated circuit comprising:
- a variable gain amplifier including:
- a multiplier to multiply an M-bit baseband sample of an RF signal by an N-bit gain factor to generate a product having M+N bits,
- a shift register to shift the M-bit baseband sample by N bits to generate a shifted value having M+N bits, and
- a bit selector to generate an output by selecting at least a subset of M+N+1 bits of a sum of the product and the shifted value;
- and
- an automatic gain control unit that defines the gain factor.
An integrated circuit comprising:
- an automatic gain control unit that measures a power level of baseband samples of a received RF signal and accumulates measured power level errors for a number of baseband samples;
- and
- a digital variable gain amplifier that adjusts a gain factor as a function of the accumulation and applies the adjusted gain factor to scale the baseband samples.
An apparatus comprising:
- means for multiplying an M-bit baseband sample of an RF signal by an N-bit gain factor to generate a product having M+N bits;
- means for shifting the M-bit baseband sample by N bits to generate a shifted value having M+N bits;
- and
- means for generating an output by selecting at least a subset of M+N+1 bits of a sum of the product and the shifted value.
An apparatus comprising:
- means for measuring a power level of baseband samples;
- means for accumulating differences between the measurements and a set point;
- means for adjusting a gain factor as a function of the accumulation;
- and
- means for applying the adjusted gain factor to scale the baseband samples.
Dependencies are inferred from the claim text.