889 research outputs found
A Millimeter Wave MIMO Testbed for 5G Communications
This paper presents a 2 x 2 millimeter wave (mm-wave)
multiple-input-multiple-output (MIMO) testbed that operates at around 30 GHz.
The link assessment of the system operating at 26.25 GHz was carried out on a
test bench, with a short communication distance between the transmitting and
receiving antennas. A user-programmable, reconfigurable and real-time signal
processing field-programmable gate arrays (FPGAs)-based software defined radio
(SDR) system was employed as part of the testbed to validate the system-level
performance for a downlink time division long-term evolution (TD-LTE) duplex
scheme. Constellation diagram for quadrature phase shift keying (QPSK) digital
modulation were acquired while the testbed was operating at 30 GHz. The testbed
could be employed for the development of signal test, communication algorithm
and measurement metrology for 5G communications.Comment: 89th ARFTG Microwave Measurement Conference (ARFTG 2017
Modulation Schemes and Connectivity in Wireless Underground Channel
In this chapter, a thorough treatment of the modulation schemes for UG Wireless is presented. The effects of soil texture and water content on the capacity of multi-carrier modulation in WUC are discussed. The multi-carrier capacity model results are analyzed. Moreover, the underground MIMO design for underground communications is explained thoroughly. An analysis of medium access in wireless underground is done as well. Furthermore, the soil properties are considered for cross-layer communications of UG wireless. The performance analysis of traditional modulation schemes is also considered. The soil moisture-based modulation approach is also explored in this chapter. The connectivity and diversity reception approaches are discussed for wireless underground communications. The connectivity and interference models are studied for Ad-Hoc and Hybrid Networks. The topology control mechanisms for maintaining network connectivity are explored for maximizing network capacity under the physical models (e.g., the protocol interference model and physical interference model). Moreover, the underground diversity is examined for 3W-Rake receiver and coherent detection along with experimental evaluation and comprehensive analysis of performance of equalization techniques
Design guidelines for spatial modulation
A new class of low-complexity, yet energyefficient Multiple-Input Multiple-Output (MIMO) transmission techniques, namely the family of Spatial Modulation (SM) aided MIMOs (SM-MIMO) has emerged. These systems are capable of exploiting the spatial dimensions (i.e. the antenna indices) as an additional dimension invoked for transmitting information, apart from the traditional Amplitude and Phase Modulation (APM). SM is capable of efficiently operating in diverse MIMO configurations in the context of future communication systems. It constitutes a promising transmission candidate for large-scale MIMO design and for the indoor optical wireless communication whilst relying on a single-Radio Frequency (RF) chain. Moreover, SM may also be viewed as an entirely new hybrid modulation scheme, which is still in its infancy. This paper aims for providing a general survey of the SM design framework as well as of its intrinsic limits. In particular, we focus our attention on the associated transceiver design, on spatial constellation optimization, on link adaptation techniques, on distributed/ cooperative protocol design issues, and on their meritorious variants
Spatial Modulation for Multiple-Antenna Wireless Systems : A Survey
International audienceMultiple-antenna techniques constitute a key technology for modern wireless communications, which trade-off superior error performance and higher data rates for increased system complexity and cost. Among the many transmission principles that exploit multiple-antenna at either the transmitter, the receiver, or both, Spatial Modulation (SM) is a novel and recently proposed multiple- uniqueness and randomness properties of the wireless channel for communication. This is achieved by adopting a simple but effective coding mechanism that establishes a one-to-one mapping between blocks of information bits to be transmitted and the spatial positions of the transmit-antenna in the antenna-array. In this article, we summarize the latest research achievements and outline some relevant open research issues of this recently proposed transmission technique
Spatial Modulation with Energy Detection: Diversity Analysis and Experimental Evaluation
In this paper, we present a non-coherent energy detection scheme for spatial
modulation (SM) systems. In particular, the use of SM is motivated by its
low-complexity implementation in comparison to multiple-input multiple-output
(MIMO) systems, achieved through the activation of a single antenna during
transmission. Moreover, energy detection-based communications restrict the
channel state information to the magnitude of the fading gains. This
consideration makes the design applicable for low-cost low-powered devices
since phase estimation and its associated circuitry are avoided. We derive an
energy detection metric for a multi-antenna receiver based on the
maximum-likelihood (ML) criterion. By considering a biased pulse amplitude
modulation, we develop an analytical framework for the SM symbol error rate at
high signal-to-noise ratios. Numerical results show that the diversity order is
proportional to half the number of receive antennas; this result stems from
having partial receiver channel knowledge. In addition, we compare the
performance of the proposed scheme with that of the coherent ML receiver and
show that the SM energy detector outperforms its coherent counterpart in
certain scenarios, particularly when utilizing non-negative constellations.
Ultimately, we implement an SM testbed using software-defined radio devices and
provide experimental error rate measurements that validate our theoretical
contribution.Comment: This work has been submitted to an IEEE journal for possible
publicatio
- …