Synchronization sensitivity of block-IFDMA systems

In this paper, we present a comprehensive study of the performance of a new model of DFT-precoded OFDMA with block-interleaved subcarrier allocation: B-IFDMA. The impact of the phase and timing jitter on the performance degradation for the two variants of B-IFDMA, namely joint-DFT and added-signal B-IFDMA is studied. Theoretical expressions of the degradation are derived for the additive white Gaussian noise channel and are compared with classical multicarrier schemes (OFDMA, MC-CDMA). Numerical results with various jitter parameters are presented and discussed. For the maximum number of active users, which is the critical case, it is shown that the phase jitter affects the two B-IFDMA variants and the classical multicarrier schemes in a similar fashion. Also, our results demonstrate that the two B-IFDMA variants are more sensitive to timing jitter than classical multicarrier schemes for a small number of blocks. Additionally, the number of blocks allocated to each user is found critical to minimize the degradation that occurs when timing jitter is introduced, and, therefore, must be carefully chosen.