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We consider the deployment of a large-scale circular layout-distributed antenna system. To maximize energy efficiency, we define the optimization problem with the approximated analysis and find the number of deployed antennas as a closed-form solution. In simulation results, we verify that the analysis based on approximation is accurate and the closed-form solution can achieve near-optimal energy efficiency without an exhaustive search method. [ABSTRACT FROM AUTHOR]

We propose a time synchronization method which is applicable to both offset quadrature amplitude modulation based filter-bank multicarrier (FBMC-OQAM) system and quadrature amplitude modulation based filter-bank multicarrier (FBMC-QAM) system. Based on the relation between the transmitted data symbols and FBMC signal, we design the scattered symbols to make a specific time domain region empty. Then, we insert the preamble in that region so as to transmit it perfectly. The performance of the proposed synchronization method is compared with the conventional time synchronization methods for the FBMC systems in terms of root mean square error (RMSE) of symbol timing offset (STO), bit error ratio (BER) and correctly detected data bit ratio per frame. Since the proposed method can reduce the resource usage for the synchronization, the resources for data transmission can be increased, thereby improving the spectral efficiency of the FBMC systems. [ABSTRACT FROM AUTHOR]

In this paper, we evaluate the performance of a filter-bank multicarrier-quadrature amplitude modulation (FBMC-QAM) system with two prototype filters. We analyze the effective channel and derive the signal-to-interference ratio for additive white Gaussian noise channels and multipath fading channels. Based on the analysis, the characteristics of the effective channel according to various prototype filter sets and channel models are investigated. Utilizing the effective channels, we design two types of per-tone channel equalizers and evaluate the bit error rate performances by Monte Carlo simulations. The simulation results show that the FBMC-QAM system with two prototype filters can achieve almost the same bit error rate performance as orthogonal frequency division multiplexing with cyclic prefix by adopting the signal-level per-tone channel equalizer. Finally, the computational complexity of per-tone channel equalizers is analyzed. [ABSTRACT FROM AUTHOR]

This paper proposes a channel estimation scheme for the filter-bank multicarrier systems with quadrature amplitude modulation (FBMC-QAM). Under frequency selective channels, the adjacent data symbols cause interference to the pilot symbols in FBMC-QAM systems and degrade the performance of the channel estimation. To handle this problem, we analyze the interference of the pilot symbols in an oversampled frequency domain before the receiver filtering process. Exploiting the interference analysis, we propose a pilot symbol configuration and condition of filter coefficients to cancel the inter-carrier interference. Moreover, we apply a time domain data symbol precoding to eliminate inter-symbol interference. The simulation results show that the proposed scheme outperforms conventional channel estimation schemes. [ABSTRACT FROM AUTHOR]