The reason why the power consumption of LTE PA increases compared with GSM is because the dynamic range of signal power is large. The uplink (from the terminal to the base station) communication of the LTE terminal uses the SC-FDMA communication method to transmit radio waves. Although it is a single carrier, it introduces the concept of OFDM (Orthogonal Frequency Division Duplex), so it has the characteristics of resistance to multi-path interference. The peak-to-average ratio (PAPR) of the time axis waveform of the transmitted signal when using SC-FDMA is larger than that of W-CDMA (Figure A-1). Although SC-FDMA has the characteristics of lower PAPR than when using OFDM, it is still higher than W-CDMA in the past. Figure A-1: ​​The difference between the peak and average values ​​of the LTE signal is large This figure shows the typical time axis signal waveforms of W-CDMA, HSUPA, and LTE. The peak-to-average ratio (PAPR) of the signal waveform amplitude is about 3.5dB in W-CDMA, and rises to about 8.5dB in LTE. (The picture was made by this magazine based on the information of Nujira company) The PA needs to have the characteristic of accurately tracking the input signal for output within this dynamic range, that is, "linearity". However, if you want to use PA in areas with high linearity, you need to greatly reduce the margin (Margin Width) from the saturated output power. This margin is called "back off". To fully ensure back-off, a PA with a large saturation output power is required, so the power consumption will increase accordingly. Therefore, the larger the PAPR, the higher the power consumption of the PA. Other,Mini Cheap 5km Walkie Talkie,Cheap Light Weight Radio For Outdoor,Baofeng Ham Radio Guangzhou Etmy Technology Co., Ltd. , https://www.gzdigitaltalkie.com