NOMA System: Calculating User Outage Probability and System Throughput

NOMA (Non-Orthogonal Multiple Access) is a key technology in 5G and future wireless communication systems, enabling multi-user simultaneous transmission in the same frequency band through power-domain multiplexing. Calculating user outage probability and system throughput are crucial metrics for evaluating NOMA system performance. From an implementation perspective, these calculations typically require MATLAB or Python simulations involving channel modeling and SIC (Successive Interference Cancellation) algorithms.

Outage probability reflects the likelihood of communication failure due to channel conditions. The calculation method must consider: channel fading characteristics, power allocation schemes among users, and interference cancellation capability at the receiver. A typical analytical process involves establishing a statistical model for SINR (Signal-to-Interference-plus-Noise Ratio) and deriving closed-form outage expressions through probability integration. In code implementation, this often requires creating Rayleigh/Rician fading channel models and implementing numerical integration functions to compute the cumulative distribution function of SINR.

System throughput measures the amount of data successfully transmitted per unit time, requiring the integration of transmission rates from multiple users. NOMA's unique characteristics include: 1) Near users (with better channel conditions) employ SIC technology; 2) Far users (with poorer channel conditions) receive higher transmission power. This asymmetric design makes throughput calculation dependent on parameters like user pairing and power allocation coefficients. Implementation typically involves creating iterative algorithms that simulate SIC decoding processes and calculate achievable rates based on Shannon capacity formulas.

Common analytical approaches in practice include: establishing rate expressions based on Shannon capacity combined with outage probability for expected value calculations; or using asymptotic analysis methods to study throughput performance bounds under high SNR conditions. These metric calculations can guide power allocation algorithm design and user scheduling strategy optimization in NOMA systems. Code implementation often requires optimization toolbox usage for solving power allocation problems and Monte Carlo simulations for performance validation.