公开(公告)号：US08666346B1

公开(公告)日：2014-03-04

申请号：US13594506

申请日：2012-08-24

Applicant: Sira Parasurama Rao ,  John Elliott Whitecar

Inventor： Sira Parasurama Rao ,  John Elliott Whitecar

IPC: H04B1/16

CPC classification number: H04L25/022 ,  H03D3/00 ,  H04B1/1646 ,  H04H40/72

Abstract: An FM receiver is unaware of the modulation level (frequency deviation) of the signal and has to make an estimate of it, or some reasonable time-average of it, and accordingly set the input filter's bandwidth. We calculate modulation by measuring the autocorrelation of the recovered audio signal instead of its peaks, and then applying a peakhold detector. Since FM noise can be modeled to be somewhat uncorrelated, we can expect to get an accurate estimate of signal power while rejecting noise power substantially if we measure a one-sample delayed autocorrelation estimate. Since the above measurement is alike a power measurement, we compute its square root, gain adjust it to obtain a cleaner peak measurement, and then track these clean peaks using a leaky integrator. This gives an estimate of modulation that subdues the effect of the noise.

Abstract translation: FM接收机不知道信号的调制级别（频率偏差），并且必须对其进行估计，或者对其进行一些合理的时间平均，并因此设置输入滤波器的带宽。 我们通过测量恢复的音频信号的自相关而不是其峰值来计算调制，然后应用峰值检测器。 由于FM噪声可以被模拟为有些不相关，所以如果我们测量单样本延迟自相关估计值，我们可以期望获得信号功率的准确估计，同时抑制噪声功率。 由于上述测量与功率测量类似，我们计算其平方根，增益调整它以获得更干净的峰值测量，然后使用泄漏积分器跟踪这些干净的峰值。 这给出了抑制噪声影响的调制估计。

公开(公告)号：US20140057582A1

公开(公告)日：2014-02-27

申请号：US13594506

申请日：2012-08-24

Applicant: Sira Parasurama Rao ,  John Elliott Whitecar

Inventor： Sira Parasurama Rao ,  John Elliott Whitecar

IPC: H04L25/02

CPC classification number: H04L25/022 ,  H03D3/00 ,  H04B1/1646 ,  H04H40/72

Abstract: An FM receiver is unaware of the modulation level (frequency deviation) of the signal and has to make an estimate of it, or some reasonable time-average of it, and accordingly set the input filter's bandwidth. We calculate modulation by measuring the autocorrelation of the recovered audio signal instead of its peaks, and then applying a peakhold detector. Since FM noise can be modeled to be somewhat uncorrelated, we can expect to get an accurate estimate of signal power while rejecting noise power substantially if we measure a one-sample delayed autocorrelation estimate. Since the above measurement is alike a power measurement, we compute its square root, gain adjust it to obtain a cleaner peak measurement, and then track these clean peaks using a leaky integrator. This gives an estimate of modulation that subdues the effect of the noise.

Abstract translation: FM接收机不知道信号的调制级别（频率偏差），并且必须对其进行估计，或者对其进行一些合理的时间平均，并因此设置输入滤波器的带宽。 我们通过测量恢复的音频信号的自相关而不是其峰值来计算调制，然后应用峰值检测器。 由于FM噪声可以被模拟为有些不相关，所以如果我们测量单样本延迟自相关估计值，我们可以期望获得信号功率的准确估计，同时抑制噪声功率。 由于上述测量与功率测量类似，我们计算其平方根，增益调整它以获得更干净的峰值测量，然后使用泄漏积分器跟踪这些干净的峰值。 这给出了抑制噪声影响的调制估计。