Integrated Wireless-pon access Network Architectures Milos Milosavljevic

FDM Simulation Platform with Wireless Compatibility 
0.68V were required to achieve -31dB EVM 
QAM modulation in WiMAX [4]. This estimation is 
k transmission of the OFDM signal in the absence of the 
wireless channel. The obtained spectrum at the output of the amplifier is shown in Figure 4-9 
maximum achievable SNR 
is fundamental in evaluating wireless 
. Parameters that affect signal transmission across the air are typically the path loss 
and multipath delay spread. Therefore, the model must be carefully designed to account for 
scenarios. There are various 
established models for evaluating the performance of wireless channels for fixed application, 
signal strength prediction and simulation in macro-
applies only to frequencies 

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Chapter 4 FDM Simulation Platform with Wireless Compatibility 
78 
between 500 – 1500 MHz with possible extension up to 2 GHz [10]. However, 4G wireless 
networks are expected to operate in frequency ranges above 2 GHz. For application over urban 
environments the Cost 231 Walfish-Ikegami (W-I) model [11, 12] could have been alternatively 
considered but is also limited to maximum frequencies of 1.9 GHz.
To that effect, an empirical based path loss model has been utilized that in view of appropriate 
frequency correction factors has successfully addressed the baud requirements of the intended 
specification channels [13]. The model parameters, presented in Appendix B, have been 
extensively used to calculate the appropriate wireless channel path losses of the simulation 
models presented particularly in chapter 6. 
In addition to path loss, wireless channels display multipath delay and fading profiles due to 
signal scattering. As a result, a complementary model had to be implemented. This is described 
in the following section and has been widely used for emulating the wireless channel in fixed 
radio applications, such as in IEEE802.16d.