1
GATE ECE 2007
+2
-0.6
In a GSM system, 8 channels can co-exist in 200 KHz bandwidth using TDMA. A GSM based cellular operator is allocated 5 MHz bandwidth. Assuming a frequency reuse factor of 1/5, i. e. a five-cell repeat pattern,, the maximum number of simultaneous channels that can exist in one cell is
A
200
B
40
C
25
D
5
2
GATE ECE 2007
+2
-0.6
The raised cosine pulse p(t) is used for zero ISI in digital communications. The expression for p(t) with unity roll-off factor is given by $$p(t) = {{\sin \,4\,\pi \,W\,t} \over \matrix{ 4\,\pi \,W\,t(1 - 16{W^2}{t^2}) \hfill \cr \hfill \cr \hfill \cr} }$$\$ The value of p(t) at $$t = {1 \over {4\,W}}$$ is
A
- 0.5
B
0
C
0.5
D
$$\infty$$
3
GATE ECE 2007
+2
-0.6
In a Direct sequence CDMA system the chip rate is $$1.2288\,\, \times \,\,{10^6}$$ chips per second. If the processing gain is desired to be at least 100. The data rate
A
must be less than or equal to $$12.288\,\, \times \,\,{10^3}$$ bits per sec.
B
must be greater than $$12.288\,\, \times \,\,{10^3}$$ bits per sec.
C
must be exactly equal to $$12.288\,\, \times \,\,{10^3}$$ bits per sec.
D
can take any value less than $$12.288\,\, \times \,\,{10^3}$$ bits per sec.
4
GATE ECE 2006
+2
-0.6
The minimum step-size required for a Delta-Modulator operating at 32 K samples/sec to track the signal (here u(t) is the unit-step function)

x(t) = 125t(u(t) - u (t - 1) + (250 - 125t) (u (t - 1) - u (t - 2 )) so that slope - overload is avoided, would be

A
$${2^{ - 10}}$$
B
$${2^{ - 8}}$$
C
$${2^{ - 6}}$$
D
$${2^{ - 4}}$$
GATE ECE Subjects
Network Theory
Control Systems
Electronic Devices and VLSI
Analog Circuits
Digital Circuits
Microprocessors
Signals and Systems
Communications
Electromagnetics
General Aptitude
Engineering Mathematics
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