ENC3250 Solutions pg 29 - 7.2 The total number of tones or...

-29-
7.2 The total number of tones, or individual channels is:
W
s
/ f
d
= (400 MHz)/(100 Hz) = 4 × 10
6
.
The minimum number of PN bits =  log
2
(4 × 10
6
)  = 22
where  x  indicates the smallest integer value not less than x. Source: [SKLA01]
7.3 W
s
= 1000 f
d
; W
d
= 4 f
d
; Using Equation 7.3 , G
p
= W
s
/ W
d
= 250 = 24 dB
7.4 a. Period of the PN sequence is 2
4
– 1 = 15
b. MFSK
c. L = 2
d. M = 2
L
= 4
e. k = 3
f. slow FHSS
g. 2
k
= 8
h.
Time 0 1 2 3 4 5 6 7 8 9 10 11
Input data 0 1 1 1 1 1 1 0 0 0 1 0
Frequency f
1
f
3
f
3
f
2
f
0
f
2
Time 12 13 14 15 16 17 18 19
Input data 0 1 1 1 1 0 1 0
Frequency f
1
f
3
f
2
f
2
7.5 a. Period of the PN sequence is 2
4
– 1 = 15
b. MFSK
c. L = 2
d. M = 2
L
= 4
e. k = 3
f. fast FHSS
g. 2
k
= 8
h. Same as for Problem 7.4
7.6 a. This is from the example 6.1.
f
1
= 75 kHz 000 f
2
=125 kHz 001 f
3
= 175 kHz 010