Signal Processing for Communication Systems
Mathuranathan Estimator bias: Systematic deviation from the true value, either consistently overestimating or underestimating the parameter of interest. Estimator Bias: Biased or Unbiased Consider a simple communication system model where a transmitter transmits continuous stream of data samples representing a constant value – ‘A’. The data samples sent via a communication channel gets added with White … Read more
Digital Modulations 101 — 5 lessons (same on every page in this path) 1. BPSK → 2. QPSK → 3. M-PSK sim → 4. QAM sim (you are here) → 5. EVM Tools: BER vs Eb/N0 · EVM → SNR · Eb/N0 ↔ SNR Also on the Matlab → Python path (lesson 3 of 4): … Read more
Digital Modulations 101 — 5 lessons (same on every page in this path) 1. BPSK → 2. QPSK → 3. M-PSK sim (you are here) → 4. QAM sim → 5. EVM Tools: BER vs Eb/N0 · EVM → SNR · Eb/N0 ↔ SNR Also on the Matlab → Python path (lesson 4 of 4): … Read more
BPSK Lab path:Derive BER (theory) → AWGN noise model → BER simulation (Python & Matlab)Tools: BER vs Eb/N0 calculator · Shannon capacity The BPSK bit error rate for an optimum receiver in AWGN follows from a simple decision-threshold argument. This post derives it step by step, then checks the result with a Monte Carlo simulation … Read more
What the Gaussian Q-function, erf, and erfc mean, how to convert between them, and how they appear in AWGN BER formulas — with a plot, Python, and a link to the BER calculator.
Introduction to estimation theory: what an estimator is, bias vs variance, and how the path leads to Fisher information and the Cramér–Rao bound.
In GMSK modulation (used in GSM and DECT standard), a GMSK signal is generated by shaping the information bits in NRZ format through a Gaussian Filter. The filtered pulses are then frequency modulated to yield the GMSK signal. GMSK modulation is quite insensitive to non-linearities of power amplifier and is robust to fading effects. But … Read more
Bandpass / IF undersampling: choose sampling rates inside allowed zones so the replica does not alias — with formulas and a live bandpass sampling demo.
Nyquist–Shannon sampling for baseband signals: sample faster than twice the highest frequency, or aliases fold into band.
OFDM BER simulation vs Eb/N0 in Matlab with cyclic prefix: MPSK/MQAM on subcarriers in AWGN, and how results compare to single-carrier theory.