| 摘要 |
A method of linearizing an amplifier to produce an amplified output sample va in response to a predistorted input sample vd derived from an input modulation sample vm, such that va &persp& Kvm, where K is the amplifier's desired constant amplitude gain. The squared magnitude xm of the input modulation sample vm is first derived. A table entry Fi is then selected from a table containing Nt values Fi where i=0, 1, . . . Nt-1. Each table entry corresponds to a squared magnitude value xmi; and, for each table entry, FiG(xmi¦Fi¦2) &persp& K, where G(x) is the complex gain of the amplifier. The table entry selected is the one for which the absolute value ¦xm-xmi¦ is minimized with respect to the table index i. The predistorted sample vd is then derived, in rectangular coordinates, as vd=vmFi, viz: Re(vd)=Re(vm)Re(Fi)-Im(Vm)Im(Fi) Im(vd)=Re(vm)Im(Fi)+Im(Vm)Re(Fi) where Re(x) is the real component of x and Im(x) is the imaginary component of x.
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