| 摘要 |
Improved radio receiver designs can be used in the operational environment of wireless telephone communications. The radio receiver includes a variable attenuator, a variable-current RF signal amplifier, and a controller. The controller controls the amount of attenuation provided by the variable attenuator, and/or the current consumed by the variable-current RF signal amplifier, in response to signals received by the RF signal amplifier. The controller adjusts the variable attenuator, and/or the RF signal amplifier, to achieve a minimum symbol error rate and/or to maximize the signal-to-noise and interference ratio for a desired signal, irrespective of the levels of any interfering signals received by the RF signal amplifier. In this manner, the variable attenuator, and/or the variable current RF signal amplifier, are adjusted to obtain just the right amount of intermodulation performance for a given set of receiving conditions. This technique saves operating current and minimizes noise figure because, in practice, interference conditions do not persist all of the time, and are usually of temporary duration.
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