包络解调分析在轴承故障诊断中的应用，可为故障诊断提供方法-Envelope demodulation analysis in Bearing Fault Diagnosis for fault diagnosis method

包络分析大多在原始振动加速度信号基础上进行， 受噪声干扰等因素的影响较大 通过对原始振动信号自相关函数作包络分析， 可以有效地抑制噪声， 突出反映故障调制特征-s． Most of the envelope analyses are based on original vibration accelera- tion signal，which is seriously influenced by noise interference． The noise is effectively sup

Frequency Synchronization in OFDM System An accurate frequency synchronization method using the zadoff-chu (ZC) constant envelop preamble is analyzed, and a new preamble weighted by pseudo-noise sequence is used for orthogonal frequency division mu