公开(公告)号：US20060072656A1

公开(公告)日：2006-04-06

申请号：US10956292

申请日：2004-10-01

申请人： John Wiss ,  Timothy Blalock

发明人： John Wiss ,  Timothy Blalock

IPC分类号： H04B3/46 ,  H04L27/22

CPC分类号： H04L1/20 ,  H04B17/336

摘要： The signal-to-noise ratio of a demodulated received signal is estimated by measuring the error vector magnitude (EVM) of the demodulated signal; and processing the measured EVM in combination with a correction term to estimate the signal-to-noise ratio of the demodulated signal. The correction term is a polynomial function of the measured EVM. The signal-to-noise ratio is estimated in accordance with the formula: E S N 0 ≅ 10 · LOG 10 ⁡ ( π · ⌈ E S ⌉ 4 ⁡ [ μ ^ z + C ⁡ ( μ ^ z ) ] 2 ) ⁢   ⁢ ( dB ) wherein {circumflex over (μ)}z is the measured EVM based on the mean of a Rayleigh density of EVM measurements; and C is the correction term. For QPSK modulated signals, C is calculated in accordance with the formula: CQPSK({circumflex over (μ)}z)≅2.71×10−3{circumflex over (μ)}z3−7.54×10−2{circumflex over (μ)}z2+0.7{circumflex over (μ)}z−2.25 For BPSK modulated signals, C is calculated in accordance with the formula: CBPSK({circumflex over (μ)}z)≅1.78×10−4{circumflex over (μ)}z3−1.03×10−3{circumflex over (μ)}z2+4.62×10−2{circumflex over (μ)}z−0.588