Power supply adjustment and polar modulation in a MIMO system
Aspects of a method and system for power supply adjustment and polar modulation in a MIMO system are provided. In each RF transmit chain of a MIMO system that utilizes polar modulation, aspects of the invention may enable generating a signal representative of an amplitude of a pair of phase-quadrature baseband signals; and controlling a voltage and/or current regulator utilizing said generated signal. In this regard, a voltage and/or current supplied to a power amplifier and/or mixer of one or more of the transmit chains may be controlled based on the generated signal. Additionally, a gain of a power amplifier for each RF transmit chain may be controlled utilizing said signal representative of an amplitude. The signal representative of an amplitude may be generated by squaring each of the phase-quadrature baseband signals and calculating a square root of a sum of the squared signals.
1. A method for signal processing, the method comprising:
in each radio frequency (RF) transmit chain of a multiple input multiple output (MIMO) system that utilizes polar modulation
generating a signal representative of an amplitude of a pair of phase-quadrature baseband signals;
controlling a supply voltage or a supply current generated by a voltage regulator or a current regulator, the supply voltage or the supply current being linearly proportional to a square root of a sum of the pair of squared phase-quadrature baseband signals; and
modifying a power transfer curve of an amplifier of said RF transmit chain of said MIMO system according to the supply voltage or the supply current linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals, wherein
the power transfer curve of the amplifier of each RF transmit chain is modified independently of other RF transmit chains and according to the supply voltage or the supply current.
2. The method according to claim 1 , further comprising, in each RF transmit chain of the MIMO system,
performing pulse shaping respectively on the pair of phase-quadrature baseband signals;
dividing each of the pulse-shaped pair of phase-quadrature baseband signals by the signal representative of the amplitude of the pair of phase-quadrature baseband signals; and
mixing each of the divided pair of phase-quadrature baseband signals with a radio frequency (RF) carrier signal to generate a radio frequency signal.
3. The method according to claim 2 , further comprising, in each RF transmit chain of the MIMO system,
summing the radio frequency signals generated from each of the pair of phase-quadrature baseband signals to generate a phase modulated radio frequency signal,
amplifying the phase modulated radio frequency signal using the amplifier, and
transmitting the amplified phase modulated radio frequency signal.
4. The method according to claim 2 , wherein modifying the power transfer curve of the amplifier includes modifying a compression point of the amplifier according to the supply voltage or the supply current linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals.
5. The method according to claim 2 , further comprising, in each RF transmit chain of the MIMO system,
supplying a second supply voltage to mixers performing the mixing, wherein the second supply voltage is linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals.
6. A non-transitory computer-readable storage medium storing instructions thereon, which, when executed by a computer, cause the computer to perform a method comprising:
in each radio frequency (RF) transmit chain of a multiple input multiple output (MIMO) system that utilizes polar modulation
generating a signal representative of an amplitude of a pair of phase-quadrature baseband signals;
controlling a supply voltage or a supply current generated by a voltage regulator or a current regulator, the supply voltage or the supply current being linearly proportional to a square root of a sum of the pair of squared phase-quadrature baseband signals; and
modifying a power transfer curve of an amplifier of said RF transmit chain of said MIMO system according to the supply voltage or the supply current linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals, wherein
the power transfer curve of the amplifier of each RF transmit chain is modified independently of other RF transmit chains and according to the supply voltage or the supply current.
7. The non-transitory computer-readable storage medium according to claim 6 , further comprising, in each RF transmit chain of the MIMO system,
performing pulse shaping respectively on the pair of phase-quadrature baseband signals;
dividing each of the pulse-shaped pair of phase-quadrature baseband signals by the signal representative of the amplitude of the pair of phase-quadrature baseband signals; and
mixing each of the divided pair of phase-quadrature baseband signals with a radio frequency (RF) carrier signal to generate a radio frequency signal.
8. The non-transitory computer-readable storage medium according to claim 7 , further comprising, in each RF transmit chain of the MIMO system,
summing the radio frequency signals generated from each of the pair of phase-quadrature baseband signals to generate a phase modulated radio frequency signal,
amplifying the phase modulated radio frequency signal using the amplifier, and
transmitting the amplified phase modulated radio frequency signal.
9. The non-transitory computer-readable storage medium according to claim 7 , wherein modifying the power transfer curve of the amplifier includes modifying a compression point of the amplifier according to the supply voltage or the supply current linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals.
10. The non-transitory computer-readable storage medium according to claim 7 , further comprising, in each RF transmit chain of the MIMO system,
supplying a second supply voltage to mixers performing the mixing, wherein the second supply voltage is linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals.
11. A signal processing system, the system comprising:
circuitry in each radio frequency (RF) transmit chain of a multiple input multiple output (MIMO) system that utilizes polar modulation, the circuitry being configured to
generate a signal representative of an amplitude of a pair of phase-quadrature baseband signals;
control a supply voltage or a supply current generated by a voltage regulator or a current regulator, the supply voltage or the supply current being linearly proportional to a square root of a sum of the pair of squared phase-quadrature baseband signals; and
modify a power transfer curve of an amplifier of said RF transmit chain of said MIMO system according to the supply voltage or the supply current linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals, wherein
the power transfer curve of the amplifier of each RF transmit chain is modified independently of other RF transmit chains and according to the supply voltage or the supply current.
12. The system according to claim 11 , wherein the circuitry is further configured to
perform pulse shaping respectively on the pair of phase-quadrature baseband signals;
divide each of the pulse-shaped pair of phase-quadrature baseband signals by the signal representative of the amplitude of the pair of phase-quadrature baseband signals; and
mix each of the divided pair of phase-quadrature baseband signals with a radio frequency (RF) carrier signal to generate a radio frequency signal.
13. The system according to claim 12 , wherein the circuitry is further configured to
sum the radio frequency signals generated from each of the pair of phase-quadrature baseband signals to generate a phase modulated radio frequency signal,
amplify the phase modulated radio frequency signal using the amplifier, and
transmit the amplified phase modulated radio frequency signal.
14. The system according to claim 12 , wherein modifying the power transfer curve of the amplifier includes modifying a compression point of the amplifier according to the supply voltage or the supply current linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals.
15. The system according to claim 12 , wherein the circuitry is further configured to
supply a second supply voltage to mixers performing the mixing, wherein the second supply voltage is linearly proportional to the square root of the sum of the pair of squared phase-quadrature baseband signals.