In recently proposed multiple access techniques like IDMA and OFDM-IDMA, the user separation is done by user specific interleavers in contrast to the conventional CDMA scheme, where user separation is assured with user-specific signature sequences. The user specific interleavers must demonstrate minimum probability of collision amongst each other in addition to other merits, including minimal c...

Cell-Free (CF) Massive MIMO is an alternative topology for Massive MIMO networks, where a large number of single-antenna access points (APs) are distributed over the coverage area. There are no cells but all users are jointly served by the APs using network MIMO methods. In prior work, it has been claimed that CF Massive MIMO inherits the basic properties of cellular Massive MIMO, namely channe...

In this paper, we introduce a novel merger of antenna arrays with scanning beam patterns, and Orthogonal Frequency Division Multiplexing (OFDM) systems. Controlled time varying phase shifts are applied to the antenna array elements mounted at the base station with beam patterns directed toward the desired user. This creates a small beam pattern movement called Beam Pattern Scanning (BPS). In ri...

Large-scale (LS) multi-user (MU) multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) is considered to be a desirable signal transmission scheme because it can significantly improve the energy efficiency (EE) and spectral efficiency (SE) of the system. However, there are many difficulties in realizing an LS-MU-MIMO-OFDM system, and one of these is its high peak-...

Interference at the radio receiver is a key source of degradation in quality of service of wireless communication systems. This paper presents a unified framework for OFDM/FBMC interference characterization and analysis in asynchronous environment. Multi-user interference is caused by the timing synchronization errors which lead to the destruction of the orthogonality between subcarriers. In th...

We study the performance of a single-cell massive multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system that uses linear precoding to serve multiple users on the same time-frequency resource. To minimize overhead, the channel estimates at the base station are obtained via comb-type pilot tones during the training phase of a time-division duplexing system. ...

Orthogonal Frequency Division Multiplexing (OFDM) and Multicarrier Code Division Multiple Access (MC-CDMA) systems are comparatively evaluated for Power Line Communications (PLC) in a frequency-selective fading environment with additive colored Gaussian noise which is used to model the actual in-home powerline channel. OFDM serves as a benchmark in order to measure the performance of various MC...