FIGURE 3.23 Indoor delay spread example showing frequency independence.
137
As mentioned above there have been many propagation measurements from various sites and at a
variety of carrier frequencies. We have collected information from the published data and have plotted
the RMS delay spread as a function of carrier frequency, this is shown in Fig. 3.26.
138 CHAPTER THREE
Indoor RMS Delay Spread
0
50
100
150
200
250
300
350
0 10 20 30 40 50 60 70 80 90 100
Carrier Frequency (GHz)
nsec
Max RMS
FIGURE 3.26 Summary of various propagation measurements.
From a bird??™s eye view there seems to be a slight slope indicating the RMS delay spread decreases
as the carrier frequency increases. We must mention a sample support issue exists precluding us from
drawing conclusions with high statistical confidence. We nevertheless present the findings for informative
purposes (see Fig. 3.27).
Indoor RMS Delay Spread
0
50
100
150
200
250
300
350
10
Carrier Frequency (GHz)
nsec
Max RMS
NLOS
LOS
0 1 2 3 4 5 6 7 8 9
FIGURE 3.27 Summary of various propagation measurements (zoom in).
If we zoom in around the lower frequency range, we notice the data has significant variability. For
sake of simplicity and continuity we will group them into LOS and NLOS areas.
Pages:
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231