1. Chapter 7 Probability of Error for Coherent Bandpass Systems
On-off Keying with Coherent Detection
BPSK
Coherent FSK
Huseyin Bilgekul
EEE 461 Communication Systems II
Department of Electrical and Electronic Engineering
Eastern Mediterranean University

2. Bandpass (Carrier) Systems

3. Coherent Detection a) Matched Filter Detector b) Correlator Detector
Matched filter then sample and detect.
Coherently demodulate, then filter out image with matched filter and sample/detect
Coherent detector must match the phase of the input signal
Detect pulse with an output signal to noise ratio of,

4. Coherent Detection of OOK

5. Coherent Detection of OOK

6. Coherent Detection of OOK
Same as on/off (polar) signaling because we are transmitting polar as a bandpass signal.
Requires 3 dB more power than BPSK in a coherent system

7. Coherent Detection of BPSK

8. Coherent Detection of BPSK

9. Coherent Detection of BPSK
Same as polar signaling
Requires -3 dB less power than OOK in a coherent system

10. Coherent Detection of FSK
FSK signal is:
The noise power is:
The optimum threshold is VT=0
To find Ed

11. Coherent Detection of FSK
The BER becomes:
FSK is 3 dB worse than BPSK.
FSK is equivalent to OOK.

12. Coherent Detection of FSK