Transmitter Nonlinearity Compensation Without PA Power Back-Off

The patent inverts the location of the linearization function from the transmitter side to the receiver side. Instead of applying predistortion at the transmitter, the system applies post-compensation at the receiver using CDF-based amplitude nonlinearity estimation. This inversion allows the PA to operate in a more efficient region while achieving the same linearization effect through reverse engineering of the distortion characteristics at the receiver end.

The patent changes the operational parameters of the power amplifier by eliminating the need for power back-off. By using CDF-based amplitude nonlinearity estimation and post-compensation at the receiver, the system allows the PA to operate closer to its saturation point (higher input power levels) without degrading signal quality, thus changing the power operating point from conservative back-off levels to more efficient near-saturation levels.

The patent implements a feedback mechanism where the receiver estimates the amplitude nonlinearity of the PA by comparing the transmitted signal's cumulative distribution function with the received signal's CDF. This estimated nonlinearity information is then fed back to the transmitter (or used for post-compensation at the receiver) to compensate for the distortion, allowing the PA to operate at higher power levels without sacrificing signal quality.

The patent replaces the mechanical/power-domain solution of reducing input power (power back-off) with an information-processing solution. Instead of mechanically controlling the PA to operate in its linear region by reducing power, the system uses digital signal processing and statistical analysis (CDF comparison) to estimate and compensate for nonlinearity effects, substituting power control with intelligent post-processing.