Interference analysis: From 2G to 4G

Unfortunately, better throughputs are continuously requested mobile networks face spectral resource scarcity. Consequently, spectrum resource's use must be optimized for that operators have introduced frequency reuse mechanism. Unfortunately, this mechanism is limited by co-channel interference and adjacent channel interference. An Orthogonal Frequency Division Multiple Access (OFDMA) has been introduced which was also better enhanced by femto cells concept. From this work it can be deduced that the Signal to co-channel interference ratio power does not exceed 14.1 dB for a user in edge cell whereas it can achieved 15.3 dB for a user in center cell with the same path loss value (γ=3.5). The signal to adjacent channel interference power ratio decreases from 20.7 w to 6.9 w if the number of active users in the neighbor interfering cell is increased from 10 to 30. However, from the fourth generation's study, we deduce that macro user's performances are reversely varied with femto cells number. In fact, SINR decreases from 10 dB to −5 dB if we increase the number of femto cells from 1 to 7.