BPSK singlepath Rayleigh channel

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SUMMARY

The discussion focuses on deriving and simulating the error rate performance of Binary Phase Shift Keying (BPSK) over a single-path Rayleigh fading channel. The received signal is modeled as r(t) = α * exp(j * φ) * s(t) + z(t), where z(t) represents complex-valued white Gaussian noise with power spectral density N_0/2. The error rate of BPSK is expressed as P_b(γ) = Q(√(2γ)), with γ defined as γ = α² E_b / N_0, where E_b is the energy per bit. The discussion emphasizes the importance of coherent detection and matched filtering in achieving optimal performance.

PREREQUISITES
  • Understanding of Binary Phase Shift Keying (BPSK) modulation
  • Knowledge of Rayleigh fading channels and their characteristics
  • Familiarity with matched filtering techniques
  • Basic concepts of probability density functions (pdf) and error rates
NEXT STEPS
  • Study the derivation of the Q-function and its applications in communication theory
  • Explore the implementation of matched filters for BPSK signals
  • Research simulation techniques for analyzing error rates in fading channels
  • Learn about the impact of different channel conditions on BPSK performance
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Students and professionals in telecommunications, signal processing engineers, and researchers focusing on digital communication systems and error rate analysis in fading environments.

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Homework Statement


The aim of this exercise is to derive and simulate the error rate performance
of binary PSK when the signal is transmitted over a single-path (or frequency
non-selective) slowly fading channel. The frequency-nonselective channel results
in multiplicative distortion of the transmitted signal s(t). In addition, the con-
dition that the channel fades slowly implies that the multiplicative process may
be regarded as a constant during at least one signaling interval. Therefore, the
received equivalent lowpass signal in one signaling interval is

r(t) = \alpha * exp(j * \phi) * s(t) + z(t) 0 \leq t \leq ts

where z(t) represents the complex-valued white Gaussian noise process with
power spectral density N_0/2

Assume that the channel fading is sufficiently slow that the phase shift, \phi can
be estimated from the received signal without error. Then, we can achieve ideal
coherent detection of the received signal. The received signal can be processed
by passing it through a matched filter. Show that for a fixed (time-invariant)
channel, i.e., for a fixed attenuation \alpha, the error rate of binary PSK as a function
of the received SNR, \gamma is
P_b(\gamma) = Q(\sqrt{}2\gamma)
where \gamma = \alpha^2 E_b / N_0 and E_b is the energy of the transmitted signal per bit.

Homework Equations


The Attempt at a Solution


Can someone give me an idea on how to start..
 
Last edited:
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How do I go about it
i) Take the convolution of r(t) with the impulse response of a filter matched to s(t). Consider output signal and output noise separately.
ii) Remember that the modulation method is binary PSK, which means the phase shift is either 0 or pi. What is the possible output signal values?
iii) Before you compute error probability, you must obtain the pdf of the output noise.
 
Last edited:

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