| 摘要 |
A technique which enables the use of a low cost non-linear power amplifier to generate a wideband composite signal, such as in cellular mobile telephones (CMTs), personal communication system (PCSs) and other multi-channel wireless system. A constant envelope signal is generated from a wideband composite signal comprised of a combination of many narrowband modulated signals. The technique involves adding one or more out-of-band artifact signals that accurately offset the amplitude variations of the wideband composite signal. The constant envelope signal is then fed to a high power amplifier, and, prior to radio transmission the amplified signal is filtered to remove the out-of-band artifact signals. As a result, only the desired composite signal having any required envelope variations is provided to the antenna, while at the same time, only a constant envelope signal is fed through the power amplifier.
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