QoS analysis of 3G and 4G systems

The cellular communication system performance is improved by increasing channel capacity and spectrum efficiency. Spectral efficiency (SE) is a key factor in the design of cellular communication system as it quantifies how well the limited frequency spectrum resource is utilized. The efficient use of spectrum is analyzed in terms of coverage area, capacity and reuse distance. OFDMA is a very potential multiple access technique, which will be the key technique for the next generation of wireless communications (4G). In this paper the QoS parameters of OFDMA i.e. spectral efficiency [Erlangs/MHz/m²], system capacity is estimated and also compared with the WCDMA. The other important parameters which analyses the performance of cellular OFDMA system are the air interface capacity and the degradation in OFDMA signal user due to multiple access interference also estimated. OFDMA system offers better QoS parameters such as 1.5 times more spectral efficiency and 6 times more capacity than WCDMA system.