| Summary: | 碩士 === 國立交通大學 === 電機學院碩士在職專班電子與光電組 === 95 === The paper treat the result of signal distortion by different modulated signal after Power Amplifier. We analyze the parameters, EVM (Error Vector Magnitude) and find Magnitude error is the dominant factor. By the way, IEEE 802.11b for WLAN includes 4 kinds of digital modulation such as 1M/2M/5.5M/11M bps , BPSK/DQPSK/OQPSK/QPSK. Each modulation has different EVM performance. Then we compare the difference by different encoding of 802.11b modulation.
To improve the worse signal performance with larger Output Power, we design a compensated system which can de-modulate parameter and record data to LUT(Look-up table).We transmit compensated value in LUT to the data source by automatically controlling instruments and improve signal quality. The EVM performance can be improved 15~29% and doesn’t need any closed-loop algorithm.
The Power Amplifier Sample is normal IC , which can be get easily, Part No.SST12LP14A,typical gain=29dB,operating frequency= 2.4G~2.5GHz
Current consumption=240mA, efficiency=25%.
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