 the IFFT module being utilized for transmission in the uplink [7]. This type of carrier aggregation slightly increases the uplink peak-to-average power ratio compared to that of Rel-8; however, the PAPR is still kept lower than that of OFDMA and therefore the increase in terminal power consumption as result of wideband transmissions is minimized. Note that if the sub- carriers of the contiguous bands are perfectly aligned, the baseband processing of the OFDMA signals can be performed with a single FFT/IFFT module (if the size is practically feasible from implementation point of view) or multiple FFT/IFFT modules (one per component carrier). As an example, if two 10 MHz contiguous bands are aggregated and the sub-carriers are perfectly aligned, we can use one 2048-point FFT/IFFT unit or two 1024-point FFT/IFFT modules for baseband processing. In typical TDD deployments, the number of component carriers and the bandwidth of each component carrier in the uplink and downlink will be the same. The component carriers originating from the same eNB are not required to provide the same coverage, which can be the case when the center frequencies of the component carriers are far apart. The frequency separation between center frequencies of contiguously aggregated component carriers is a multiple of 300 kHz in order to be compatible with the 100 kHz frequency raster of 3GPP LTE Rel-8 and at the same time to preserve orthogonality of the sub-carriers with 15 kHz sub-carrier spacing. Depending on the aggregation scenario, the gap between two contiguous carriers can be filled by insertion of a small number of unused sub-carriers. In the 3GPP LTE technical specification, 10% of the total system bandwidth is allocated to the guard bands between adjacent component carriers. The multi-carrier load balancing method is important when carrier aggregation is utilized. There are two carrier load balancing techniques that may be considered. Round Robin load balancing (also referred to as Combined Carrier Channel Assignment) is used to 