L64780 LSI Logic Corporation, L64780 Datasheet - Page 17

• Manufacturer Part Number: L64780
• Description: Dvb-t Cofdm Demodulator Technical Manual 2/00
• Manufacturer: LSI Logic Corporation

1.6 Typical Performance
Figure 1.4
the simulation results in the ETSI specification for all the nonhierarchical
modes in a Gaussian channel. Differences between the target
performance and the simulations are accounted for as follows:
It is not possible to be specific about the source of the remaining small
difference (about 0.4 dB) because we do not have enough information
about the conditions under which the simulations were performed.
The two losses (in the channel equalizer and channel state information)
are compromises made in the interests of the speed of tracking of a
time-varying channel. Sacrificing the tracking ability reduces the losses.
Figure 1.4
Typical Performance
25
20
15
10
5
0
Stand-alone FFT mode (forward or inverse)
Easy connection to the L64705 or L64724 for FEC
160-pin PQFP package
About 1.5 dB for the noisy reference effect in the channel equalizer
0.1–0.3 dB for noise on the channel state measurement
1/2 2/3 3/4 5/6 7/8
QPSK
illustrates the target performance of the L64780 compared to
Measured QEF
Simulated QEF from specification
Performance with Additive Write Gaussian Noise
(AWGN)
1/2 2/3 3/4 5/6 7/8
16 QAM
1/2 2/3 3/4 5/6 7/8
64 QAM
1-7