We propose a Mutual Information (MI) based spatial frequency domain packet scheduling algorithm for uplink Orthogonal Frequency Division Multiple Access (OFDMA) multiuser multiple-input, multiple-output (MIMO) systems in this paper. The proposed scheduler is designed particularly for signal constellation constrained MIMO systems. The superiority of the investigated scheduler coupled with the in...

In this paper, we study the performance of block diagonalization (BD) scheme for a downlink multiuser multi-input multi-output (MIMO) system with imperfect channel state information (CSI). At each mobile user, information about the channel is obtained by applying the minimum mean-square-error (MMSE) channel estimation method. The channel state information is fed back to the base station through...

Massive MIMO is a variant of multiuser MIMO in which the number of antennas at the base station (BS) M is very large and typically much larger than the number of served users (data streams) K. Recent research has illustrated the system-level advantages of such a system and in particular the beneficial effect of increasing the number of antennas M . These benefits, however, come at the cost of d...

In a heterogeneous network consisting of macro base stations (MBSs) and small base stations (SBSs), the traditional cell association policy, i.e., coupled access (CA), is far from optimal, due to the significant difference between the coverage and transmit powers of MBSs and SBSs. Hence, users may choose to associate with different types of BSs in downlink (DL) and uplink (UL), i.e., decoupled ...

Applying spatial mode switching in channel adaptive MIMO systems promises to achieve high spectral efficiencies in practical system setups. Several studies have pointed out significant performance gains obtained in realistically modeled channel scenarios. We have conducted channel measurements with the Berlin LTE-Advanced Testbed operated in the city center of Berlin and used these for the perf...

In an Orthogonal Frequency Division Multiplexing (OFDM) system, downlink beamforming can be implemented either before IDFT (frequency domain) or after IDFT (time domain) module in a base station transmitter. We denote the former scheme as PreIDFT downlink beamforming, and the latter as Post-IDFT downlink beamforming. In this work, we have compared Pre-IDFT downlink beamforming with Space-Time B...

The performance of multi-user Orthogonal Frequency Division Multiplexing (OFDM) with raised cosine time domain pulse shaping is studied on the Satellite Mobile channel (SMC) and the two-path Rayleigh Fading channel. A multi-user time and carrier frequency synchronization scheme is discussed. The relationship between the synchronization requirement and the roll-off rate (B) of the pulse shaping ...

This paper investigates the Multi-band OFDM (MB-OFDM) based physical (PHY) layer proposal for IEEE 802.15.3a working group on short-range high data-rate Ultra-wide-Band (UWB) communications. An overview of the MB-OFDM PHY layer architecture with its various parameters is presented and the optimal choice of critical parameters is discussed. Next, we derive the theoretical un-coded Bit Error Rate...

Frequency division multiplexing (FDM) is a technology that transmits multiple signals simultaneously over a single transmission path, such as a cable or wireless system. Each signal travels within its own unique frequency range (carrier), which is modulated by the data (text, voice, video, etc.). For multimedia implementations, consider the more efficient and robust OFDM (orthogonal frequency d...