An Orthogonal Frequency Division Duplex (OFDD) System Using an Analog Filter Bank

We have proposed a multi-carrier based duplexing, or orthogonal frequency division duplex (OFDD), that realizes the flexible radio resource management. In this paper, we propose a new OFDD system using an analog filter bank. The aim of the analog filter bank is moderating the difficulty of analog circuit designs and solving the signal dynamic range problem in the OFDD. The OFDD system approaches a practical one with the help of the analog filter bank. In this paper, we investigate the sub-carrier configuration for OFDD and evaluate the effect of the analog filter bank. Then, we evaluate the bit error rate performance of the OFDD using the analog filter bank in the presence of carrier frequency offset by computer simulations. From the results, we observe that four null sub-carriers are sufficient for a given analog filter bank to avoid the nonlinear degradation at the analog circuit. We also observe that the OFDD system almost achieves the ideal bit error rate performance when the normalized carrier frequency offset is 10^-2.