LDPC Code Performance Analysis and BER Comparison with Uncoded QPSK

In the rapidly evolving landscape of modern communication systems, the demand for high-speed, reliable, and efficient data transmission has never been greater. This paper compares Low-Density Parity-Check (LDPC) codes and uncoded Quadrature Phase Shift Keying (QPSK) modulation, focusing on their technical principles, performance characteristics, and practical applications. LDPC codes, known for their near-Shannon limit error correction and efficient parallel decoding, are widely used in high-speed data transmission scenarios such as 5 G networks, digital TV broadcasting, and IoT devices. QPSK modulation offers high spectral efficiency and robustness against interference, making it suitable for satellite communication and mobile networks. The paper evaluates their performance in terms of bit error rate (BER), transmission rate, bandwidth efficiency, and implementation complexity. Simulation results show that LDPC encoding significantly outperforms uncoded QPSK in reducing BER, especially at higher signal-to-noise ratios (SNR), while maintaining competitive bandwidth efficiency. The paper also discusses their applicability in different communication scenarios, including high and low SNR environments, highspeed data transmission, and resource-constrained settings. Finally, it highlights future research directions, such as optimizing LDPC codes for IoT devices and addressing QPSK's limitations through advanced modulation techniques.