1. ECEN4523 Commo Theory Lecture #29 26 October 2015 Dr
ECEN4523 Commo Theory Lecture # October 2015 Dr. George Scheets
Read 7.5
Problems: 7.7-2, 4, & 5
Exam #2, 30 October (Live) [Chapter 4 – Chapter 7]
Remote DL students < 6 November
Design Problem, due 6 November (Live)
Remote DL students < 13 November

2. ECEN4523 Commo Theory Lecture #30 28 October 2015 Dr
ECEN4523 Commo Theory Lecture # October 2015 Dr. George Scheets
Read 7.7 & 7.8
Problems: & & 3
Exam #2, 30 October (Live) [Chapter 4 – Chapter 7]
Remote DL students < 6 November
Design Problem, due 6 November (Live)
Remote DL students < 13 November
Quiz 5 Results
High = 10, Low = 1.0, Ave = 7.13, σ = 2.69

3. Binary ASK
1.5
1 MHz
-1.5
.00001
Two different Amplitudes are transmitted
10 cycles/ seconds = 1 MHz (cycles/second)
5 cycles/symbol
200 K symbols/second = 200 K bits/second

4. Receiver Coherent Detection
Low Pass
Filter
Digital
Decision X
cos(2πfct)
Generate a frequency and phase locked sinusoid
Multiply by received signal
Filter out double frequency term
Output is a noisy baseband symbol stream
Decide which symbol was probably transmitted
Requires syncing to the symbol stream
Output a cleaned up version

5. Binary PSK 1.5 1 MHz -1.5 .00001 Two different phases are transmitted
-1.5
.00001
Two different phases are transmitted
10 cycles/ seconds = 1 MHz
5 cycles/symbol
200 K symbols/second = 200 K bits/second

6. Unfiltered b Spectrum

7. Binary FSK 1.5 -1.5 .00001 Two different frequencies are transmitted
-1.5
.00001
Two different frequencies are transmitted
Symbol #1) 5 cycles/ seconds = 1 MHz
Symbol #2) 10 cycles/ seconds = 2 MHz
1.5 MHz Average (center) Frequency
2 symbols in seconds =
200 K symbols/second = 200 K bits/second

8. PSK Signal Constellations
Distance along I axis is cosine Vpeak
Distance along Q axis is sine Vpeak
Use negative voltage if sine or cosine inverted
Distance from origin is magnitude
[Vcosine_peak2 + Vsine_peak2] 0.5
source: slideplayer.com

9. 16 QAM Signal Constellations
Distance along I axis is cosine Vpeak
Distance along Q axis is sine Vpeak
Use negative voltage if sine or cosine inverted
Distance from origin is magnitude
[Vcosine_peak2 + Vsine_peak2]0.5
source: waltertech426.blogspot.com/2013/08/matlab-m-ary-quadrature-signal.html & Wikipedia