Amplifier linearization by adaptive predistortion

Details Amplifier linearization by adaptive predistortion Amplifier linearization by adaptive predistortion

1990-04-20

1991-09-17

Mottola, Steven

Amplifiers

Hum or noise or distortion bucking introduced into signal...

332160, H03F 126

Patent

active

050498320

ABSTRACT:
A method of linearizing an amplifier to produce an amplified output sample v.sub.a in response to a predistorted input sample v.sub.d derived from an input modulation sample v.sub.m, such that v.sub.a .perspectiveto.Kv.sub.m, where K is the amplifier's desired constant amplitude gain. The squared magnitude x.sub.m of the input modulation sample v.sub.m is first derived. A table entry F.sub.i is then selected from a table containing N.sub.t values F.sub.i where i=0, 1, . . . N.sub.t -1. Each table entry corresponds to a squared magnitude value x.sub.mi ; and, for each table entry, F.sub.i G(x.sub.mi .vertline.F.sub.i .vertline..sup.2).perspectiveto.K, where G(x) is the complex gain of the amplifier. The table entry selected is the one for which the absolute value .vertline.x.sub.m -x.sub.mi .vertline. is minimized with respect to the table index i. The predistorted sample v.sub.d is then derived, in rectangular coordinates, as v.sub.d =v.sub.m F.sub.i, viz:

REFERENCES:
patent: 4291277 (1981-09-01), Davis et al.
patent: 4412337 (1983-10-01), Bickley et al.
patent: 4462001 (1984-07-01), Girard
patent: 4554514 (1985-11-01), Whartenby et al.
patent: 4700151 (1987-10-01), Nagata
Y. Akaiwa and Y. Nagata, "Highly Efficient Digital Mobile Communications with a Linear Modulation Method", IEEE J. Sel. Areas in Comms., vol. SAC-5, No. 5, pp. 890-895, Jun. 1987.
A. Bateman, D. M. Haines and R. J. Wilkinson, "Linear Transceiver Architectures", Proc. IEEE Vehic. Tech. Conf., pp. 478-484, Philadelphia, 1988.
S. Ono, N. Kondoh and Y. Shimazaki, "Digital Cellular System with Linear Modulation", Proc. IEEE Vehic. Tech. Conf., pp. 44-49, San Francisco, 1989.
M. Nannicini, P. Magni, and F. Oggioni, "Temperature Controlled Predistortion Circuits for 64 QAM Microwave Power Amplifiers", IEEE MTT-S Digest, pp. 99-102, 1985.
J. Namiki, "An Automatically Controlled Predistorter for Multilevel Quadrature Amplitude Modulation", IEEE Trans. Comm., vol. COM-31, No. 5, pp. 707-712, May 1983.
H. Girard and K. Feher, "A New Baseband Linearizer for More Efficient Utilization of Earth Station Amplifiers Used for QPSK Transmission", IEEE J. Selected Areas in Commun., vol. SAC-1, No. 1, pp. 46-56, Jan. 1983.
J. Graboski and R. C. Davis, "An Experimental MQAM Modem Using Amplifier Linearization and Baseband Equalization Techniques", Proc. Natl. Commun. Conf., pp. E3.2.1-E3.2.6, 1982.
A. A. M. Saleh and J. Salz, "Adaptive Linearization of Power Amplifiers in Digital Radio Systems", Bell Syst. Tech. J., vol. 62, No. 4, pp. 1019-1033, Apr. 1983.
Y. Nagata, "Linear Amplification Technique for Digital Mobile Communications", Proc. IEEE Vehic. Tech. Conf., pp. 159-164, San Francisco, 1989.

Affiliated with

Also associated with

Rating

Amplifier linearization by adaptive predistortion does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Amplifier linearization by adaptive predistortion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Amplifier linearization by adaptive predistortion will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1919411