Rohde & Schwarz R&S FSL3 - Analysis

R&S FSL WiMAX, WiBro Measurements (Options K92/K93)
1300.2519.12 2.157 E-11
Analysis
The analysis block of the OFDMA measurement application allows to calculate a variety of
measurement variables.
EVM
The most important variable is the error vector magnitude (EVM).
kl
klkl
k
l
a
ar
EVM
,
,,
,
ˆ
ˆ

222
=
(37)
on subcarrier
k at OFDM symbol l . The subsequent average values can be derived from (37).
1. EVM of subchannel
n
at OFDM symbol l :
%
=
n
n
k
klnl
EVM
N
EVM
c
h
c
h
2
,
sc
subchannel,
1
(38)
2. EVM of all pilot subcarriers:
%%
=
lk
kl
EVM
N
EVM
p
p
2
,
sc
pilots
1
(39)
3. EVM of all data subcarriers:
%%
=
lk
kl
EVM
N
EVM
d
d
2
,
sc
data
1
(40)
4. EVM of all used subcarriers:
%%%
7
7
,
*
8
8
+
)
+=
lk
kl
k
kl
EVMEVM
N
EVM
d
d
p
p
2
,
2
,
sc
all
1
(41)
The number of subcarriers respectively taken into account is denoted by
sc
N .
CINR
The carrier to interference and noise ratio is determined for each subframe
n
. The computation is
based on the partially compensated samples
kl
r
,
2
2
, the decided symbols
kl
a
,
ˆ
, and the channel estimates
k
H
ˆ
(DL: preamble and fine; UL: fine).
%%
%
%

22

=
lk
kklkl
lk
kkl
Har
Ha
nCINR
2
,,
2
,
|
ˆ
ˆ
|
|
ˆ
ˆ
|
)( (42)
Further CINR statistics are defined in the standards [5], [6].
dB ))(
ˆ
)(
ˆ
(log5)(
ˆ
0)()1(
ˆ
)1(
0)0(
)(
ˆ
dB )(
ˆ
log10)(
ˆ
0)()1(
ˆ
)1(
0)0(
)(
ˆ
2
CINR
2
CINR
(dB)
CINR
2
avg
2
CINRavg
2
2
CINR
CINR
(dB)
CINR
avgCINRavg
CINR
nnxn
nnCINRnx
nCINR
nx
nn
nnCINRn
nCINR
n
µ/

µµ
µ
µ
=
3
9
3
:
;
>+
=
=
=
9
:
;
>+
=
=
(43)