قارن الطرق

	تضمين التردد بتقسيم التعامد (OFDM)	نموذج انتشار تتبع الأشعة
المجال	الاتصالات	الاتصالات
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1971	1993
صاحب الطريقة	Weinstein and Ebert	Maciel, Bertoni, and Xia
النوع	multicarrier modulation scheme	deterministic propagation algorithm
المصدر التأسيسي	Weinstein, S. B., & Ebert, P. M. (1971). Data transmission by frequency-division multiplexing using the discrete Fourier transform. IEEE Transactions on Communication Technology, 19(5), 628-634.	Maciel, T. F., Bertoni, H. L., & Xia, H. H. (1993). Unified approach to prediction of propagation over buildings for all ranges of frequencies. IEEE Transactions on Vehicular Technology, 42(1), 41-45.
الأسماء البديلة	multicarrier modulation	deterministic propagation, site-specific modeling
ذات صلة	5	4
الملخص	OFDM is a multicarrier modulation technique that divides a wideband channel into many narrowband orthogonal subcarriers. Introduced by Weinstein and Ebert in 1971, it exploits the duality between time and frequency domains to efficiently use spectrum while mitigating intersymbol interference in frequency-selective channels. OFDM is now the standard for high-speed wireless systems including WiFi, cellular LTE, and digital broadcasting.	Ray tracing is a deterministic propagation modeling technique for predicting electromagnetic field strength at specific locations. Instead of empirical formulas (like Okumura-Hata), ray tracing traces paths of electromagnetic energy as it reflects, diffracts, and scatters off buildings and terrain. With accurate 3D geometry and material properties, ray tracing predicts site-specific path loss, multipath delay profiles, and angle of arrival, making it ideal for detailed coverage planning, interference analysis, and system design. Ray tracing is now standard in professional cellular planning tools.