Browsing by Author "Fan, Pingzhi"
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Article Citation Count: 13Conditional Power and Rate Adaptation for MQAM/OFDM Systems Under CFO With Perfect and Imperfect Channel Estimation Errors(IEEE-INST Electrical Electronics Engineers Inc, 2015) Panayırcı, Erdal; Fan, Pingzhi; Panayırcı, Erdal; Lei, XianfuIn this paper a new conditional power and rate adaptation scheme for orthogonal frequency-division multiplexing (OFDM) systems is proposed in the presence of carrier frequency offset (CFO) with perfect and imperfect channel state information (CSI). The conventional adaptive scheme is shown to be a special case of the conditionally adaptive scheme technique that enables the resulting nonconvex optimization problem which is solved in a feasible way. It leads to a solution for optimal power adaptation that maximizes the spectral efficiency of an OFDM system using M-ary quadrature amplitude modulation (MQAM) under average power and instantaneous bit error rate (BER) constraints. Closed-form expressions for the average spectral efficiency (ASE) of adaptive OFDM systems are derived for perfect and imperfect CSI cases. The theoretical results and computer simulations show that range of the conditional adaptation becomes narrow and the performance of constant power and continuous rate is very close to that of the conditionally adaptive power and continuous rate for higher CFO or high signal-to-noise ratio (SNR) values.Article Citation Count: 13Effect of power and rate adaptation on the spectral efficiency of MQAM/OFDM system under very fast fading channels(Springer International Publishing Ag, 2012) Panayırcı, Erdal; Fan, Pingzhi; Panayırcı, Erdal; Mathiopoulos, P. TakisIn this article the effect of power and rate adaptation on the spectral efficiency of orthogonal frequency division multiplexing (OFDM) systems using M-ary quadrature amplitude modulation (MQAM) is investigated in the presence of frequency selective and very rapidly time-varying fading channels under power and instantaneous bit error rate (BER) constraints. Lower bounds on the maximum spectral efficiency of adaptive OFDM/MQAM systems with perfect and imperfect channel state information (CSI) are obtained together with a closed-form expression for the average spectral efficiency of adaptive OFDM systems. The delay between the channel estimation and the actual transmission is also considered in this article. The theoretical and numerical results show that the adaptive MQAM/OFDM systems under fast fading channels have substantial gains in spectral efficiency over the non-adaptive counterparts with perfect CSI or moderate imperfect CSI. The theoretical and numerical results also show that a good way to deal with the delay CSI under very rapidly time-varying channels is to increase the subcarrier bandwidth of the OFDM system while ignoring the impact of the cyclic prefix.Conference Object Citation Count: 0An Efficient SAGE-based Data Detection Algorithm for OFDM Systems in the Presence of Very Fast Fading Channels(IEEE, 2013) Panayırcı, Erdal; Fan, Pingzhi; Panayırcı, ErdalIn this paper an iterative and computationally efficient data detection algorithm is proposed based on the space alternating generalized expectation maximization (SAGE) technique for orthogonal division multiplexing (OFDM) systems under fast fading channels. The proposed detector includes the original detector presented in [1] as one of its special cases. With a proper choice of its parameters simulations show that the new detector has negligible performance loss than original one in [1] with smaller number of iterations.Article Citation Count: 4Guest editorial: special issue on high mobility wireless communications(2012) Panayırcı, Erdal; Panayırcı, Erdal; Li, Ping; Wang, Chengxiang; Tarokh,Vahid[Abstract Not Available]Conference Object Citation Count: 0Partial Power and Rate Adaptation for MQAM/OFDM Systems under CFO(IEEE, 2014) Panayırcı, Erdal; Fan, Pingzhi; Panayırcı, Erdal; Lei, XianfuIn this paper a new partial power and rate adaptation scheme for orthogonal frequency division multiplexing (OFDM) systems is proposed in the presence of carrier frequency offset (CFO). The conventional adaptive scheme is shown to be a special case of the partially adaptive scheme technique which enables the resulting non-convex optimization problem solved in a feasible way. It leads to a solution for optimal power adaptation that maximizes the spectral efficiency of an OFDM system using M-ary quadrature amplitude modulation (MQAM) under average power and instantaneous BER constraints. Closed-form expressions for the average spectral efficiency (ASE) of adaptive OFDM systems are derived. The theoretical results and computer simulations show that the range of the partial adaptation becomes narrow and the performance of constant power and continuous rate is very close to that of the partially adaptive power and continuous rate for higher CFO or high signal noise ratio (SNR) values.Article Citation Count: 4Power and Rate Adaptation Based on CSI and Velocity Variation for OFDM Systems Under Doubly Selective Fading Channels(IEEE-INST Electrical Electronics Engineers Inc, 2016) Panayırcı, Erdal; Fan, Pingzhi; Lei, Xianfu; Panayırcı, ErdalIn this paper a novel joint continuous power and rate adaptation scheme is proposed fordoubly selective fading channels in orthogonal frequency division multiplexing (OFDM) systems based on terminal velocity and perfect or imperfect channel state information (CSI). The analysis and simulation results show that the continuous power and rate adaptation scheme is very effective and improve the performance of OFDM systems substantially under time-varying fading channels as compared with the traditional adaptation schemes operating without a priori knowledge of velocity and mobility adaptation without CSI.Conference Object Citation Count: 1Power and rate adaptation for MQAM/OFDM systems under fast fading channels(IEEE, 2012) Panayırcı, Erdal; Fan, Pingzhi; Zhou, Weixi; Panayırcı, ErdalIn this paper the effect of power and rate adaptation on the spectral efficiency of orthogonal frequency division multiplexing (OFDM) systems using M-ary quadrature amplitude modulation (MQAM) is investigated in the presence of the fast fading channels under power and instantaneous bit error rate (BER) constraints. A lower bound on the maximum spectral efficiency of adaptive OFDM/MQAM systems is obtained together with a closed-form expression for the average spectral efficiency of adaptive OFDM systems. Theoretical and numerical results show that the adaptive MQAM/OFDM systems under fast fading channel have substantial gain in spectral efficiency over the non-adaptive counterparts.Editorial Citation Count: 8Special issue on broadband mobile communications at very high speeds(Springer International Publishing Ag, 2012) Panayırcı, Erdal; Panayırcı, Erdal; Poor, H. Vincent; Mathiopoulos, P. Takis[Abstract Not Available]
