A Real-Time Wireless Channel Emulator for MIMO Systems

2006 ◽  
Author(s):  
Hamid Eslami ◽  
Ahmed Eltawil
Keyword(s):  
Real Time ◽  
Mimo Systems ◽  
Wireless Channel ◽  
Channel Emulator

QoS Support Mechanisms in WiMAX

2010 ◽  
pp. 330-346
Author(s):  
Maode Ma ◽  
Jinchang Lu
Keyword(s):  
Real Time ◽  
Packet Scheduling ◽  
Wireless Channel ◽  
Wireless Access Networks ◽  
Broadband Wireless ◽  
Wimax Networks ◽  
Real Time Traffic ◽  
Support Mechanisms ◽  
Time Varying Channel

Quality of service (QoS) provisioning is an important issue in the deployment of broadband wireless access networks e.g. WiMAX (IEEE Std 802.16-2004, 2004) networks with real-time and non-real-time traffic integrated. To design a QoS support framework tailored for WiMAX networks is more challenge as wireless channel has unique characteristics such as time-varying channel and limited channel capacity. This chapter presents various QoS support mechanisms in WiMAX networks. Existing proposals with the state-of-the-art technology have been classified into three main categories: QoS support architecture, bandwidth management mechanism, and packet scheduling schemes. Representative schemes from each of the categories have been evaluated with respect to major distinguishing characteristics of the WiMAX MAC layer and PHY layer as specified in the IEEE 802.16d standard. Suggestions and research trends on QoS support in WiMAX networks are highlighted.

Multi-Gigabit/s OFDM real-time based transceiver engine for emerging 5G MIMO systems

2020 ◽  
Vol 38 ◽  
pp. 100957 ◽  
Author(s):  
Carlos Ribeiro ◽  
Rodolfo Gomes ◽  
Luís Duarte ◽  
Akram Hammoudeh ◽  
Rafael F.S. Caldeirinha
Keyword(s):  
Real Time ◽  
Mimo Systems

scholarly journals Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Slavche Pejoski ◽  
Venceslav Kafedziski
Keyword(s):  
Real Time ◽  
Fading Channels ◽  
Video Transmission ◽  
Single Layer ◽  
Rate Distortion ◽  
Wireless Channel ◽  
Video Encoding ◽  
Cross Layer ◽  
Mimo Channels ◽  
Channel Errors

We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

scholarly journals Real-time Distributed MIMO Systems

2016 ◽  
Author(s):  
Ezzeldin Hamed ◽  
Hariharan Rahul ◽  
Mohammed A. Abdelghany ◽  
Dina Katabi
Keyword(s):  
Real Time ◽  
Mimo Systems

scholarly journals Joint Design of Massive MIMO Precoder and Security Scheme for Multiuser Scenarios under Reciprocal Channel Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Gustavo Anjos ◽  
Daniel Castanheira ◽  
Adão Silva ◽  
Atílio Gameiro ◽  
Marco Gomes ◽  
...  
Keyword(s):  
Channel Capacity ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Mimo System ◽  
Wireless Channel ◽  
Joint Design ◽  
Security Scheme ◽  
Working Principle ◽  
Transmitted Signal ◽  
Intended Receiver

The exploration of the physical layer characteristics of the wireless channel is currently the object of intensive research in order to develop advanced secrecy schemes that can protect information against eavesdropping attacks. Following this line of work, in this manuscript we consider a massive MIMO system and jointly design the channel precoder and security scheme. By doing that we ensure that the precoding operation does not reduce the degree of secrecy provided by the security scheme. The fundamental working principle of the proposed technique is to apply selective random rotations in the transmitted signal at the antenna level in order to achieve a compromise between legitimate and eavesdropper channel capacities. These rotations use the phase of the reciprocal wireless channel as a common random source between the transmitter and the intended receiver. To assess the security performance, the proposed joint scheme is compared with a recently proposed approach for massive MIMO systems. The results show that, with the proposed joint design, the number of antenna elements does not influence the eavesdropper channel capacity, which is proved to be equal to zero, in contrast to previous approaches.

scholarly journals Practical and Simple Wireless Channel Models for Use in Multipolarized Antenna Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
KwangHyun Jeon ◽  
Xin Su ◽  
Bing Hui ◽  
KyungHi Chang
Keyword(s):  
Channel Model ◽  
Mimo Systems ◽  
Wireless Channel ◽  
Spatial Multiplexing ◽  
Channel Models ◽  
Data Rates ◽  
Outdoor Environments ◽  
Wireless Channel Models ◽  
2D And 3D ◽  
Antenna Systems

The next-generation wireless systems are expected to support data rates of more than 100 Mbps in outdoor environments. In order to support such large payloads, a polarized antenna may be employed as one of the candidate technologies. Recently, the third generation partnership standards bodies (3GPP/3GPP2) have defined a cross-polarized channel model in SCM-E for MIMO systems; however, this model is quite complex since it considers a great many channel-related parameters. Furthermore, the SCM-E channel model combines the channel coefficients of all the polarization links into one complex output, making it impossible to exploit the MIMO spatial multiplexing or diversity gains in the case of employing polarized antenna at transmitter and receiver side. In this paper, we present practical and simple 2D and 3D multipolarized multipath channel models, which take into account both the cross-polarization discrimination (XPD) and the Rician factor. After verifying the proposed channel models, the BER and PER performances and throughput using the EGC and MRC combining techniques are evaluated in multipolarized antenna systems.

Sign in / Sign up

Export Citation Format

Share Document