Comparison of spectrum efficiency between FDMA and TDMA in digital cellular

A comparison of spectrum efficiency between TDMA (time-division multiple access) and FDMA (frequency-division multiple access) in digital cellular systems was made. In theory, these two schemes do not differ in terms of spectrum efficiency. However, in a practical application, due to the actual signal reception of the mobile units in a mobile radio environment, several effects are found to make TDMA inferior to FDMA for mobile-unit reception. When the received signal becomes weaker, i.e. at a lower value of the carrier-to-interference ratio, the FDMA degrades gracefully but the TDMA degrades more rapidly