Training sequence and digital linearization process for power amplifier
A training sequence and digital linearization process for a power amplifier are provided. In particular, a system for maintaining linear operation of an amplifier is includes an estimation component configured to determine compensation coefficients. The system further includes a digital pre-distorter configured to compensate for non-linear operation of the amplifier based on the compensation coefficients. The compensation coefficients are determined based on a training sequence signal having a time synchronization portion and a linearization sequence portion.
1 . A system for maintaining linear operation of an amplifier, the system comprising:
an estimation component configured to determine compensation coefficients; and
a digital pre-distorter configured to compensate for non-linear operation of the amplifier based on the compensation coefficients, wherein the compensation coefficients are determined based on a training sequence signal having a time synchronization portion and a linearization sequence portion.
2 . A system in accordance with claim 1 wherein the linearization sequence portion is transmitted at a substantially higher amplitude than the time synchronization potion.
3 . A system in accordance with claim 1 wherein the time synchronization portion is transmitted at an amplitude that causes the amplifier to operate in a linear region and the linearization sequence portion is transmitted at an amplitude that causes the amplifier to operate in a non-linear region.
4 . A system in accordance with claim 1 wherein the time synchronization portion is transmitted at a substantially wider bandwidth than the linearization sequence portion.
5 . A system in accordance with claim 1 wherein the training sequence signal is transmitted at a constant phase.
6 . A system in accordance with claim 1 wherein the estimation component determines the compensation coefficients based on a binning of a plurality of signal responses based on a plurality of transmitted linearization sequence portions.
7 . A system in accordance with claim 6 wherein the estimation component determines the compensation coefficients based on a weighting of signal responses in each of a plurality of bins resulting from the binning process.
8 . A system in accordance with claim 7 wherein the estimation component determines the weighting based on a distance of each of the responses from a center of a bin and a signal to noise ratio (SNR).
9 . A system in accordance with claim 1 wherein the time synchronization portion comprises a pseudo-random sequence.
10 . A system in accordance with claim 1 wherein the pre-distorter is configured for real time compensation.
11 . A training sequence signal for maintaining linear operation of an amplifier, the training sequence signal comprising:
a time synchronization portion having a first amplitude causing the amplifier to operate in a linear-region; and
a linearization sequence portion having a second amplitude causing the amplifier to operate in a non-linear region.
12 . A training sequence signal in accordance with claim 11 wherein the time synchronization portion comprises a pseudo-random sequence.
13 . A training sequence signal in accordance with claim 11 wherein the training sequence signal comprises a fixed phase signal.
14 . A training sequence signal in accordance with claim 11 wherein the training sequence signal comprises a real signal.
15 . A method for maintaining the linear operation of an amplifier, the method comprising:
transmitting a training sequence signal having a time synchronization portion and a linearization sequence portion;
performing at least one of channel access request, signal detection, time synchronization of a wireless receiver and frequency synchronization of a wireless receiver based on at least one response from the time synchronization portion; and
performing linearization of the amplifier based on at least one response from the linearization sequence portion.
16 . A method in accordance with claim 15 further comprising driving the amplifier in a linear region during transmission of the time synchronization portion and driving the amplifier in a non-linear region during transmission of the linearization sequence portion.
17 . A method in accordance with claim 15 further comprising generating a pseudo-random sequence to define the time synchronization portion.
18 . A method in accordance with claim 15 further comprising determining compensation coefficients for the amplifier based on a plurality of signal responses to the linearization sequence portion.
19 . A method in accordance with claim 18 further comprising binning the signal responses into a plurality of bins.
20 . A method in accordance with claim 19 further comprising weighting the response signals corresponding to each of the plurality of bins.