Rohde & Schwarz CMU-K20, Руководство по эксплуатации

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CMU-K20/K21/K22/K23/K24
Signalling: Receiver Quality Measurements
1115.6088.12 4.123 E-12
determined by the difference of the data field size compared to the complete RLC
block size. For other coding schemes, there are additional effects originating from
the different channel coding of the header and data fields and from differences in
the bit error rate of header and data bits after the channel decoder. A comparison
of the two coding schemes CS4 and CS1 is shown in
Fig. 4- below
.
10 -4 10 -3 10 -2
0
10
20
30
40
50
60
70
80
90
100
[%]
Bit error rate after demodulator
BLER
DBLER
BLER - DBLER
10
-
-3
10 -2
0
10
20
30
40
50
60
70
80
90
Bit error rate after channel decoder
[%]
BLER DBLER
BLER - DBLER
100
Fig. 4-57 Comparison between BLER and DBLER: CS4 (left diagram) and CS1
Frame Structure for Speech and Data Channels
The data stream used for bit error rate measurements is divided into units containing an equal number
of bits, the so-called frames (see parameters
Frames, Average
and
RLC Block Count
in section
Measurement Control (Receiver Quality Configuration – Control)
on p. 4.138 ff.). The bit content of the
frames depends on the service (see
Main Service
softkey on p. 4.92 and
Service Selection
softkey on
p. 4.192 ), the frame type (burst, speech, data, RLC data blocks) and the channel coding (see
Traffic
Mode
softkey on p. 4.170 ). The following tables are to shed light on the different frame structures and
on the statistics of
Receiver Quality
tests.
Table 4-10 Frame structure for Main Service: Circuit Switched
Frame type Channel coder Bits per frame
Bursts All GMSK Full Rate channel coders 114
All GMSK Half Rate channel coders 57
*)
All 8PSK Full Rate channel coders (MCS5 to MCS9 Test Mode) 346
Speech Frames Full Rate Version 1 260
Full Rate Version 2 244
Half Rate Version 1 112
Data Blocks Full Rate Data 4800 120
Full Rate Data 9600 240
Full Rate Data 14400 290
Half Rate Data 2400 72
Half Rate Data 4800 120
CS1 Test Mode 160
**) 114 bits per burst. As every second burst is cancelled the average bit content is 57 bit/burst.
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