Robert L. Olesen

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A salient advantage of single carrier frequency division multiple access (SC-FDMA) is low peak-to-average power ratio (PAPR) which is lower than that of OFDMA. Precoding using transmit beamforming (TxBF) is a MIMO spatial multiplexing method that increases the data throughput significantly. However, when applied to SC-FDMA, it increases the PAPR. In this(More)
In this paper, we propose a new waveform based on discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM), in which the tail of the DFT-SOFDM symbol contains a fixed sequence, i.e., a unique word (UW). The proposed waveform, called UW DFT-S-OFDM, improves upon both existing zero-tail (ZT) DFT-S-OFDM and UW OFDM schemes by(More)
In this paper, we study carrier frequency offset estimation and correction for uplink multi-user MIMO (UL MU-MIMO) for Wi-Fi, where distributed stations (STAs) send multiple data streams to a common access point (AP) with multiple receive antennas. We provide a description of the proposed system, and propose a three-step approach using a joint phase(More)
I/Q imbalance is one of the major concerns in the design of direct-conversion front-end receivers in high data rate wireless networks. To address the challenge, various I/Q imbalance estimation and compensation algorithms have been proposed in the literature. In this paper, we propose a blind cyclostationary method based estimation and compensation of(More)
In this paper we propose an enhanced Transmit Power Control (TPC) scheme and a new fractional Carrier Sense Multiple Access with Collision Avoidance (F-CSMA/CA) scheme for use in a dense 802.11 network. The new schemes improve the energy normalized Media Access Control Goodput performance in networks with overlapping Basic Service Sets (OBSSs) by mitigating(More)