Chapter 7 Performance of Communication Systems Corrupted by Noise
1 Chapter 7 Performance of Communication Systems Corrupted by Noise
Introduction (chapter objectives) Bit error rate for binary systems(unipolar, polar, bipolar, ooK, BPSK, FSK, and Msk) Output signal-to-noise ratio for analog syster mS(AM, SSB, PM, and Fm) Information modulator Demod channel Source lator Oraeptanh Transmitting Re eceIving d noise end e How much bandwidth occupied in the air How many AM stations can be? Bandwidth ofhz L: What is the listening-performance? L> SNR e Is it very noisy to the listener? Money and time s. Equipment cost and complexity?
2 Introduction (chapter objectives) • Bit error rate for binary systems (unipolar, polar , bipolar, OOK, BPSK, FSK, and MSK) • Output signal-to-noise ratio for analog systems(AM, SSB, PM, and FM) Transmitting end Information source modulator channel Demodulator Sink Or(acceptant) Receiving end noise • How much bandwidth occupied in the air? How many AM stations can be? • What is the listening-performance? Is it very noisy to the listener? • Equipment cost and complexity? Bandwidth of Hz SNR Money and time
Introduction Eample 2: A digital communication case: e How much bandwidth occupied in the air? Data-rate of bsp or How many AM stations can be? Bandwidth ofhe What is the listening-performance? Error rate(probability of Is it very noisy to the listener? error)or SNR Equipment cost and complexity? Money and time
3 Introduction Eample 2: A digital communication case: • How much bandwidth occupied in the air? How many AM stations can be? • What is the listening-performance? Is it very noisy to the listener? • Equipment cost and complexity? Data-rate of bsp or Bandwidth of Hz Error rate (probability of error) or SNR Money and time
Introduction (chapter objectives) · Channel:nota“ free lunch” Always having a limited bandwidth With noise and even interference Often with distortion We mainly concern the most common awgn channel: Additive noise Noise is white and gaussian No distortion, maybe some amplifying ofA, maybe some delay of to Bandwidth is enough for a certain transmission
4 Introduction (chapter objectives) • Channel: not a “free lunch” – Always having a limited bandwidth – With noise, and even interference – Often, with distortion We mainly concern the most common AWGN channel: – Additive noise – Noise is White and Gaussian – No distortion, maybe some amplifying of A, maybe some delay of t0 – Bandwidth is enough for a certain transmission
Introduction In this chapter, we discuss the "performance-and-cost of communication systems SNR and/or Pe(probability of error), bit-error-rate Bandwidth and/or data-rate For digital system, For PCM For analog system, bit-error-rate system, ignal-to- of: Noise-Ratio of: OOK Signal-to- noise AM BPSK SSB R atio FSK PM QPSK FM MSK
5 Introduction In this chapter, we discuss the “performance-and-cost” of communication systems – SNR and/or Pe (probability of error), bit-error-rate – Bandwidth and/or data-rate For analog system, Signal-toNoise-Ratio of: AM SSB PM FM For digital system, bit-error-rate of: OOK BPSK FSK QPSK MSK For PCM system, Signal-toNoiseRatio