Paper Title
Interference Mitigating Coordinated Beam Forming For The Smart Antennas (FBMC/OQAM)
Abstract
In this work, we propose intrinsic interference mitigating coordinated beamforming (IIM-CBF)-based
transmission strategies for the downlink of multi-user multiple-input-multiple-out (MIMO) systems and coordinated multi-
point (CoMP) systems where filter bank based multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) is
employed. Our goal is to alleviate the dimensionality constraint imposed on the state-of-the-art solutions for FBMC/OQAM-
based space division multiple access that the total number of receive antennas of the users must not exceed the number of
transmit antennas at the base station. First, two IIM-CBF algorithms are developed for a single-cell multi-user MIMO
downlink system. The central idea is to jointly and iteratively calculate the precoding matrix and decoding matrix for each
subcarrier to mitigate the multi-user interference as well as the intrinsic interference inherent in FBMC/OQAM-based
systems. Second, for a CoMP downlink scenario where partial coordination among the base stations is considered, the
application of coordinated beam forming-based transmission schemes is further investigated. An appropriate IIM-CBF
technique is proposed. Simulation results show that when the number of transmit antennas at the base station is equal to the
total number of receive antennas of the users, the proposed IIM-CBF algorithm outperforms the existing transmission
strategies for FBMC/OQAM-based multi-user MIMO downlink systems. Moreover, we evaluate the performances of the
IIM-CBF schemes in the downlink of multi-user MIMO systems and CoMP systems where the total number of receive
antennas of users exceeds the number of transmit antennas at the base station. It is observed that by employing the IIM-CBF
techniques, FBMC/OQAM systems achieve a similar bit error rate (BER) performance as its orthogonal frequency division
multiplexing with the cyclic prefix insertion (CP-OFDM)-based counterpart while exhibiting superiority in terms of a higher
spectral efficiency, a greater robustness against synchronization errors, and a lower out-of-band radiation. In the presence of
residual carrier frequency offsets, FBMC/OQAM systems provide a much better performance compared to the CP-OFDM-
based system, which corroborates the theoretical analysis that FBMC/OQAM systems are more immune to the lack of
perfect synchronization. In addition, numerical results with respect to the convergence behavior of the IIM-CBF techniques
are presented, and the computational complexity issue is also addressed.
Keyword- Wireless Networks, Cellular Communication, Smart Antenna, Multi-Beam