CMX7164 Datasheet, PDF (116/146 Pages) CML Microcircuits – Automatic frame sync detect

CMX7164 Multi Mode Modem
1.0E-02
1.0E-03
CMX7164
16QAM Raw
16QAM Block Type 0
16QAM Block Type 6
16QAM Block Type 7
1.0E-04
1.0E-05
10
12
14
16
18
20
22
Signal to Noise Ratio / dB
Figure 95 16-QAM Performance with Different Coding Schemes
1.0E-02
1.0E-03
64QAM Raw
64QAM Block Type 0
64QAM Block Type 6
64QAM Block Type 7
1.0E-04
1.0E-05
18
20
22
24
26
28
30
Signal to Noise Ratio / dB
Figure 96 64-QAM Performance with Different Coding Schemes
The required performance of a modem may be assessed in terms of either Bit Error Rate (BER) or Packet
Error Rate (PER). The performance of both measures is affected by coding type and block size but the
PER also depends on the size of the packet. Short packets with strong coding will exhibit a much lower
PER then a long packet with no coding. A comparison of PER vs BER for 4-QAM modulation is shown in
Figure 97 based on packets of 182 bytes. The same comparisons for 16-QAM and 64-QAM are shown in
Figure 98 and Figure 99 respectively.
 2015 CML Microsystems Plc
Page 116
D/7164_FI-1.x/FI-2.x/FI-4.x/FI-6.x/22