R&S CMW-KM5 Series, Руководство пользователя

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LTE Multi Evaluation Measurement
R&S
®
CMW-KM5xx/-KS5xx
512 User Manual 1173.9628.02 ─ 16
case the general component, the IQ image component and the IQ offset component
have to be added. Then the result has to be compared to the general minimum and the
bigger value of both applies.
The following table provides an overview of the three components.
Component Value Applicable RBs
General see formula below table all non-allocated RBs
IQ Image -24.2 dB image frequencies
IQ Offset -24.2 dBc to -9.2 dBc depending on TX Power
see chapter 3.2.5.4, "I/Q Origin Offset Limits" ,
on page 511
carrier frequency
The general limit is derived using the following formula:
dB 0.8 dB
Meas Power RB Power RB
,
RB No
) 1 Offset ( 5
3 EVM log 20
,
RB No
RB All
log 10 25
max Limit
10
10
General





















     
 
   
    






 
 
  

The variables are defined as follows:
●
<All RB> = total number of RBs within the channel bandwidth of the allocated com-
ponent carrier (as defined by 3GPP, e.g. 75 RBs for 15 MHz channel bandwidth)
●
<No RB> = number of allocated RBs in the slot
●
<EVM> = maximum allowed EVM in percent (configurable), see chapter 3.2.5.2,
"Error Vector Magnitude" , on page 510
●
<Offset> = distance of the RB from the closest allocated RB
●
<RB Power> = -57 (configurable)
●
<RB Power Meas> = arithmetic mean value of the average powers in all allocated
resource blocks in dBm/180 kHz
The general minimum, the variables <EVM> and <RB Power>, the IQ image compo-
nent and the IQ offset component can be set in the configuration dialog, depending on
the modulation scheme.
Fig. 3-12: Inband emissions limit settings for QPSK
General Description
深圳德标仪器
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