Envelope extraction with reduced bandwidth for power modulation
A system according to one embodiment includes a digital data modulator configured to generate encoded symbols; an envelope detector configured to receive the encoded symbols and to estimate transmission power information associated with the encoded symbols; a peak detector configured to receive the transmission power information, detect a peak transmission power from two or more sequential data points of the received transmission power information, and to generate a power regulation signal representative of the detected peak transmission power; and a digital to analog converter (DAC) configured to receive the power regulation signal and to provide a reference voltage to a power supply associated with an RF amplifier.
1. An apparatus, comprising:
an envelope detector configured to receive quadrature amplitude modulated (QAM) constellation symbols from a digital data modulator, and to generate transmission power information based on estimated signal envelope values retrieved from a lookup table, wherein said lookup table is indexed by the in-phase and quadrature components of said QAM constellation symbols; and
a peak detector configured to receive said transmission power information, detect a peak transmission power from two or more sequential data points of said received transmission power information, the number of sequential data points determined based on a programmable parameter used to optimize power savings, and to provide a power regulation signal representative of said detected peak transmission power.
2. The apparatus of claim 1 , further comprising a low pass filter to reduce the bandwidth of said transmission power information.
3. The apparatus of claim 1 , wherein said peak detector is further configured to perform a digital maximum operation on a subset of said sequential data points of said received transmission power information.
4. The apparatus of claim 1 , further comprising a digital to analog converter (DAC) configured to receive said power regulation signal and to provide a reference voltage to a power supply associated with an RF amplifier.
5. A method, comprising:
receiving quadrature amplitude modulated (QAM) constellation symbols from a digital data modulator;
retrieving estimated signal envelope values from a lookup table, wherein said lookup table is indexed by the in-phase and quadrature components of said QAM constellation symbols;
generating transmission power information based on said estimated signal envelope;
detecting a peak transmission power from two or more sequential data points of said transmission power information, the number of sequential data points determined based on a programmable parameter used to optimize power savings; and
generating a power regulation signal representative of said detected peak transmission power.
6. The method of claim 5 , further comprising low pass filtering to reduce the bandwidth of said transmission power information.
7. The method of claim 5 , further comprising performing a digital maximum operation on a subset of said sequential data points of said received transmission power information.
8. The method of claim 5 , further comprising configuring a digital to analog converter (DAC) to receive said power regulation signal and to provide a reference voltage to a power supply associated with an RF amplifier.
9. A system, comprising:
a digital data modulator configured to generate quadrature amplitude modulated (QAM) constellation symbols;
an envelope detector configured to receive said QAM constellation symbols and to generate transmission power information based on estimated signal envelope values retrieved from a lookup table, wherein said lookup table is indexed by the in-phase and quadrature components of said QAM constellation symbols;
a peak detector configured to receive said transmission power information, detect a peak transmission power from two or more sequential data points of said received transmission power information, the number of sequential data points determined based on a programmable parameter used to optimize power savings, and to generate a power regulation signal representative of said detected peak transmission power; and
a digital to analog converter (DAC) configured to receive said power regulation signal and to provide a reference voltage to a power supply associated with an RF amplifier.
10. The system of claim 9 , further comprising a low pass filter to reduce the bandwidth of said transmission power information.
11. The system of claim 9 , wherein said peak detector is further configured to perform a digital maximum operation on a subset of said sequential data points of said received transmission power information.