Local Power Estimation in High-Speed Railway Communications

Local power estimation is essential in high-speed railway (HSR) communications. By applying the Lee's criteria and correlated shadow fading in HSR environments, we derive the lower and upper bounds of the averaging length (AL) in Ricean fading for the f rst time. With real measurement data, we f nd that the AL should be selected from about 12 to 72 wavelengths and the required sampling number changes from 28 to 88 in typical HSR scenarios. Moreover, by this method, the conf dence level is improved up to 99%. Finally, the impact of mobility on local power estimation is studied. It is found that sampling time monotonically decreases with the increase of train's speed.