EVM测量

windblow1981

公司没有条件测试EVM,但是看了AGILENT的文档,发现EVM的测量还真是很有价值
由于自己没有使用过,所以非常可以,只能以文档形式和大家分享了
真希望有一天自己也能亲自用用啊

windblow1981

【文件名】:07627@52RD_8 Hints for making and interpreting EVM measurement.rar
【格　式】:rar
【大　小】:322K
【简　介】:
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Agilent
8 Hints for Making and Interpreting
EVM Measurements
Application Note
Defining EVM
The error vector is the vector difference
at a given time between
the ideal reference signal and
the measured signal. Expressed
another way, it is the residual
noise and distortion remaining
after an ideal version of the signal
has been stripped away. EVM is
the root-mean-square (RMS) value
of the error vector over time at
the instants of the symbol (or
chip) clock transitions.
Introduction
Error vector magnitude (EVM)
measurements can provide a great
deal of insight into the performance
of digital communications
transmitters and receivers. With
proper use, EVM and related measurements
can pinpoint exactly
the type of degradations present
in a signal and can even help
identify their sources.
Primarily a measure of signal
quality, EVM provides both a simple,
quantitative figure-of-merit
for a digitally modulated signal,
and a far-reaching methodology
for uncovering and attacking
the underlying causes of signal
impairments and distortion. EVM
measurements are growing rapidly
in acceptance, being already
the required modulation quality
measurement in such important
technology standards as 3GPP
W-CDMA and IEEE 802.11a/b/g
WLAN, and they are poised to
appear in several upcoming
standards.
This application note provides
useful tips that will assist in accurately
making and understanding
EVM measurements.[br]<p align=right><font color=red>+5 RD币</font></p>

suoliwen

相当不错的东西，奖励5币！

luan246437

好啊！！！
最近正在学习这个。3GPP里面 对这个要求挺严格的。
力挺！

lynn_1981

精神非常可贵