Page 369 - Integrated Wireless Propagation Models

T h e l e e C o m p r e h e n s i v e M o d e - 1 I n e g r a t i o n o f t h e T h r e e l e e M o d e I s 347
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FIGURE 6.3.2.3.1 Cell-site, major and minor street data.

6.3.3 System Coverage i n General

6.3. . 1 Forward Link Coverage
3
Forward link coverage plot is the groundwork for analyzing performance of any cellu­
lar design. Since the propagation characteristics are critical in mobile communication, it
is important to ensure that the coverage requirement is met in the first place.
Figure 6.3.3.1.1 shows the coverage map for the study area, which is in suburban
.
areas along different highways. Figure 6.3.3 1 . 2 shows the coverage map overlay on a
3D terrain.

6.3.3.2 Antenna Patterns
The characteristics of an antenna are also an important factor when dealing with the
coverage and interference. Figure 6.3.3.2.1 shows the antenna pattern with 45° mechan­
ical downtilt. We have mentioned the advantage of using a mechanical downtilt of an
antenna in Sec. 3.1.7 1 .
.

6.3.4 COMA Coverage
From the CDMA plots, how to generate the usage of channels and other parameters is
discussed in this section. There are several different CDMA plots that are needed to
evaluate the performance of the CDMA system from both forward and reverse links.

6.3.4. 1 Forward Link Ejl. Plot
The forward link of the CDMA E/Io plot is equivalent to the normal AMPS/TDMA/
GSM forward link E/ Io coverage plot. However, the E/ Io is a negative dB value, but
E/Io is a positive dB value. The E/Io value defines the coverage of the plot channel of
the CDMA system.