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Over the air testing of multiple antenna systems has attracted great attention in recent years. The research and standardization work have been focused on evaluating user equipment (UE) in two dimension (2D) radio propagation channel models. This paper proposes two future direction of over the air testing: 1) performance evaluation of WiFi devices under realistic propagation scenarios and 2) 3D radio...
This paper addresses the optimization of a multicell network where each cell needs to select precoding matrices for beamforming in a distributed way. A modified version of the adaptive min-sum algorithm that considers reduced-size messages in the message-passing procedure is proposed. The message-passing technique, where each message is reduced to convey only part of usual information, is applied...
This paper describes the architecture and implementation of a high performance QR decomposition IEEE754 single precision floating point core, using a modified Gram-Schmidt algorithm. Using Intel's new floating point Arria 10 FPGAs, synthesis is used to generate column high functional units, giving O(n2) processing times. The modified Gram-Schmidt algorithm is expressed in a different order to combine...
Next-generation wireless and/or satellite communications require high transmission efficiency and high reliability to provide various services with subscribers. To satisfied these requirements, incorporated MIMO system with FTN techniques based on layered space time coded method are considered in the paper. To improve performance, STTC was employed as an inner code. They can yield significantly increased...
Spatial multiplexing (SM) gains in multiple input multiple output (MIMO) cellular networks are limited when used in combination with ultra-dense small cell networks. This limitation is due to large spatial correlation among channel pairs. More specifically, it is due to i) line-of-sight (LOS) communication between user equipment (UE) and base station (BS) and ii) insufficient spacing between antenna...
We derive the Multiple-Input Multiple-Output (MIMO) efficiency of the Zero-Forcing (ZF) receiver algorithm in Random Line-Of-Sight (Random-LOS). We make use of the Probability-of-Detection (PoD) curves based on the ideal digital threshold receiver model in the derivations. We show that the MIMO efficiency in this case, is mainly determined by two factors: the smallest channel gain of the two available...
LTE throughput measurements in a Random Line-of-Sight (Random-LOS) setup have been performed. The effect of polarization-randomness on the level of detection threshold of one or two bitstreams has been investigated. Good agreement is shown between theory and experiments for the SISO, SIMO and MIMO cases.
This paper presents measurement results from a distributed 4×4 multiple-input multiple-output (MIMO) trial. The measurements were performed using a 5G radio access prototype including two transmission points (TPs) and a mobile terminal over 200 MHz bandwidth at 15 GHz carrier frequency. The TPs and the mobile terminal each consists of multiple antennas, enabling spatial multiplexing. In the present...
In this paper, we propose two stop and wait (SAW) process to transmit antenna assignment schemes for multiple input multiple output (MIMO) systems with N-process SAW (N-SAW) at the data link layer. In one scheme a SAW process is statically assigned to a transmit antenna, while in the second scheme, the number of packet retransmissions and the state of the transmit antenna are used to dynamically assign...
As a promising downlink multiple access scheme for further cellular enhancements toward 5G, non- orthogonal multiple access (NOMA) improves both cell average and cell-edge user throughput compared to orthogonal multiple access (OMA). Our previous work showed that NOMA can improve system performance compared with OMA even when combined with multiple- input multiple-output (MIMO). However, for NOMA...
In this paper, a pilot reuse scheme has been considered for the uplink (UL) transmissions of a massive multiple-input multiple-output (MIMO) system. Subsequently, a lower bound on the throughput of the system, that uses a maximal ratio combining (MRC) receiver, has been derived, which is applicable for any number of antennas. The throughput, along with other metrics, has been used to differentiate...
We study the precoding for the high-rank MIMO in the LTE-A Pro systems. Unlike the low-rank precoding, layer mapping has a relatively large impact on the performance for high-rank precoding. First, we construct a model on the relationship between layer mapping and precoding. Then we derive the system throughput with the resulting model, so that the performance of the layer mapping and precoding can...
Random Linear Network coding (RLNC) has emerged as a promising solution for reliable multimedia delivery over mobile cellular networks. In this paper, we deploy Application Layer-RLNC (AL-RLNC) on the top of the existing Hybrid Automatic Repeat Request (HARQ) in 4G Long Term Evolution (LTE) networks. A simple implementation scenario composed of a user equipment, an eNB and a remote host is considered...
Currently, high-speed IEEE802.11n interfaces using MIMO have become common in access points (APs) and personal computers (PCs) for wireless local-area networks (WLANs). This trend leads to further expand the application areas for WLANs. In this paper, we present throughput measurement results of IEEE802.11n devices with various placement orientations in indoor environments. They show that measured...
We propose a novel, near-optimal data detection algorithm and a corresponding FPGA design for large multiple-input multiple-output (MIMO) wireless systems. Our algorithm, referred to as TASER (short for triangular approximate semidefinite relaxation), relaxes the maximum-likelihood (ML) detection problem to a semidefinite program and solves a non-convex approximation using a preconditioned forward-backward...
Lenstra-Lenstra-Lovász (LLL) algorithm is a common technique for lattice reduction (LR) aided multiple-input multiple-output (MIMO) detectors. This paper presents the first VLSI implementation of a recently published Incremental fixed-complexity LLL algorithm (Incremental fcLLL) with fewer iterations than other existing fcLLL algorithms. We propose a modified Incremental fcLLL algorithm with simplified...
The huge amount of smart meters and growing frequent data readings have become a big challenge on data acquisition and processing in smart grid advanced metering infrastructure systems. This requires a distributed communication architecture in which multiple distributed meter data management systems (MDMSs) are deployed and meter data are processed locally. In this paper, we present the network model...
For 5G and beyond cellular communication systems, new waveform development studies have been continuing in the whole world. Solutions for providing high throughput, high data rates, low latency, large number of terminals, supporting multiple antenna systems, and the related problems originated from these issues are playing an important role in the development of 5G and new waveform technologies. OFDM...
In this work, we present a novel technique that enables us to perform robust, low-complexity, arbitrary channel-aware precoding with single-fed load-controlled parasitic antenna arrays. Moreover, we describe the extension of this method to symbol-level and multi-cell precoding scenarios. Finally, we evaluate the sum-rate (SR) throughput performance of multi-cell zero-forcing (ZF) precoding through...
This paper studies the multi-user MIMO feature of IEEE 802.11ac networks that serve, along with IEEE 802.11ac nodes, also legacy IEEE 802.11n nodes. For this purpose, we develop a simulator that models the IEEE 802.11ac and IEEE 802.11n networks. Then, using a setup, we first study the tradeoff between the amount of overhead used in channel sounding and the corresponding rate of information, concluding...
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