Recent analysis by manufacturers and network operators has shown that current wireless networks are not very energy efficient, particularly the base stations which terminals access services from network. In response to this observation Mobile Virtual Centre of Excellence (VCE) Green Radio project was established in 2009 establish how significant savings may be obtained future systems. This article discusses technical background models consumption station devices. It also describes some most...

At present, WLANs supporting broadband multimedia communication are being developed and standardized around the world. Standards include HIPERLAN/2, defined by ETSI BRAN, 802.11a, IEEE, HiSWANa MMAC. These systems provide channel adaptive data rates up to 54 Mb/s (in a 20 MHz spacing) in 5 GHz radio band. An overview of HIPERLAN/2 802.11a standards is presented together with software simulated physical layer performance results for each transmission modes. Furthermore, differences between...

The first measured results for massive multiple-input, multiple-output (MIMO) performance in a line-of-sight scenario with moderate mobility are presented, eight users served real time using 100-antenna base station at 3.7 GHz. When such large number of channels dynamically change, the inherent propagation and processing delay has critical relationship rate as use outdated channel information can result severe detection precoding inaccuracies. For downlink (DL) particular, time-division...

In this paper the use of compressive sensing (CS) to accurately estimate sparse Power Angle Profile (PAP) a mmWave propagation channel has been investigated. This scheme is especially attractive for outdoor applications where large antenna arrays are more likely be deployed compensate high pathloss. Current analogue beamforming techniques such as codebook based 802.11ad manifest overhead typically 16×16 elements. Measurements in an anechoic chamber were performed demonstrate applicability CS...

At present, WLANs supporting broadband multimedia communications are being developed and deployed around the world. Standards include HIPERLAN/2 defined by ETSI BRAN 802.11 family IEEE. These systems provide channel adaptive data rates up to 54 Mb/s (in a 20 MHz spacing) over short ranges 200 m. The standard also specifies flexible radio access network that can be used with variety of core networks, including UMTS. It is likely will become an important complementary technology 3G cellular...

This paper explores the potential gain of joint diversity in both frequency domain and time which can be exploited to achieve spectral efficiency gains whilst simultaneously facilitating QoS/fairness an OFDMA system (particularly 3GPP Long Term Evolution (LTE)). The performance several time-frequency schedulers is investigated. Simulation results show that significantly superior compared a more conventional (only) proportional fair scheduler. schemes promising throughput while meeting...

This letter considers transmit precoding schemes based on the maximum signal-to-leakage-and-noise ratio (SLNR) in multiuser MIMO systems with single-antenna receivers. The closed-form solution of SLNR design is generally given form eigenvector associated to eigenvalue. In this letter, analytic expressions SLNR-based solutions and resulting are derived for a generic power allocation (GPA). shown be function user-allocated an arbitrary phase shift. Under equal (EPA), scheme equivalent minimum...

Pseudo medium/low voltage (MV/LV) transformer loads are usually used as partial inputs to the distribution system state estimation (DSSE) in MV systems. Such pseudo load can be represented by aggregation of smart metering (SM) data. This follows government restriction that network operators (DNOs) only use aggregated SM Therefore, we assess subsequent performance DSSE, which shows impact this - it affects angle significantly. The possibilities for improving DSSE accuracy under further...

Low delay and high reliability of safety broadcast messages are critical to future intelligent transport systems (ITS). The main objective this paper is propose a novel system model satisfy the latency requirements vehicle-to-vehicle (V2V) applications. Second, using proposed model, comprehensive performance evaluation conducted under different technologies (cellular IEEE 802.11p) for vehicle densities in rural urban scenarios based on realistic system-level simulator. further improved by...

Channel estimation and tracking pose real problems in broadband single-carrier wireless communication systems employing multiple transmit receive antennas. An alternative to estimating the channel is adaptively equalize received symbols. Several adaptive equalization solutions have been researched for operating time domain. However, these tend be computationally intensive. A low-complexity message frequency In this paper, we present an frequency-domain (FDE) algorithm implementation (SC)...

Expectations and requirements for future wireless communication systems continue to grow evolve. Thus, recently, the third generation partnership project (3GPP) has considered long term evolution (LTE) of 3G - also known as super ensure its competitiveness in future. It is generally assumed that downlink new air interface would be OFDMA based some form hybrid ARQ (HARQ) might employed. This paper aims evaluate performance various HARQ schemes over currently proposed 3GPP LTE specification....

This paper introduces a novel 128-element sub-6 GHz Massive MIMO (Multiple-Input Multiple-Output) testbed being developed by the University of Bristol in collaboration with National Instruments and Lund as part BIO (Bristol is Open) city testbed. Distributed systems avoid large single-piece antenna facets their associated windage problems also offer greater spatial diversity, but node synchronization phase alignment becomes more challenging. Simulated network performance co-located 3D...

As the Internet of Things (IoT) becomes more embedded within our daily lives, there is growing concern about risk `smart' devices pose to network security. To address this, one avenue research has focused on automated IoT device identification. Research however largely neglected identification firmware versions. There strong evidence that security relies being latest version patched for known vulnerabilities. Identifying when a updated (has changed version) or not (is stable therefore useful...

In contrast to parametric spectrum sensing, non-parametric sensing can effectively detect the primary user's presence or absence without prior information about user. Particularly, be useful in dynamic sharing. The secondary user must incumbents and peer users use licensed if is not detected using its band. detection problem goodness-of-fit testing problem. this work, we performed a hardware-in-the-loop evaluation of tests such as Cramer-von-Mises (CM), Anderson-Darling (AD)...

SC-FDMA (Single-Carrier Frequency Division Multiple Access) is employed in the 3GPP LTE (Long-Term Evolution) standard as uplink transmission scheme. The signal has a low PAPR. This makes it well-suited to power efficient at mobile terminal. Although common assumption use frequency-domain linear equalization SC-FDMA, decision feedback equalizer (DFE) composed of feedforward filter and time-domain can provide enhanced performance. Even when error propagation taken into account, results show...

The IEEE 802.11 Working Group has initiated a new study group known as 802.11ax which is aiming to devise ways improve spectrum efficiency, in particular enhance the system throughput highly dense scenarios, frequently referred Overlapped Basic Service Set (OBSS). In this paper we revisit some of common problems faced traditional WiFi networks and show how their effects could be amplified deployments, especially co-channel scenarios. We then highlight our findings through simulation based...

"Single Carrier Frequency Division Multiple Access" (SC- FDMA) is a strong candidate for uplink transmissions in the 3G Long Term Evolution (LTE) standard. SC-FDMA multiple access scheme that uses DFT spreading prior to OFDM modulation map signal from each user subset of available subcarriers. has significantly lower peak-to-average power ratio (PAPR) compared OFDM/OFDMA. This greatly improves its RF amplifier efficiency and also mean output battery driven mobile terminal. In this paper,...

Combining multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) with a massive number of transmit antennas (massive MIMO-OFDM) is an attractive way increasing the spectrum efficiency or reducing transmission energy per bit. The effectiveness Massive MIMO-OFDM strongly affected by channel state information (CSI) estimation method used. overheads training frame and CSI feedback decrease multiple access (MAC) increase cost at user station (STA). This paper...

Recent developments in orthogonal frequency division multiplexing (OFDM) and single-carrier frequency-domain equalization (SCFDE) have sparked debate about the superiority of one method over other. In this paper, we further by comparing theoretical performance OFDM SCFDE when each is implemented two different multiple-input multiple-output (MIMO) architectures: spatial space-time block codes. This study focuses on use MIMO-OFDM MIMO-SCFDE wireless local area network (WLAN) applications....

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, orthogonal frequency-division multiple-access (OFDMA) systems with dynamic deterministic (as opposed to pseudorandom) allocation of subcarriers users exploit multiuser diversity are investigated. Previously published work on subcarrrier for OFDMA single-input–single-output (SISO) channels surveyed. A near-optimal low-complexity algorithm SISO systems, which is structurally similar...

Mobile communication industries are increasingly contributing to the worldwide energy consumption and CO2 emission. This study addresses a number of key radio resource management (RRM) strategies across PHY MAC layers for reducing base station consumption, as measured by 'Joules per bit' metric. These including power efficient link adaptation, exploitation multi-user diversity trading bandwidth efficiency. By collectively taking advantage those RRM strategies, adaptive allocation algorithm...

This paper presents preliminary results for a novel 128-antenna massive Multiple-Input, Multiple-Output (MIMO) testbed developed through Bristol Is Open in collaboration with National Instruments and Lund University. We believe that the presented here validate adoption of MIMO as key enabling technology 5G pave way further pragmatic research by community. The operates real-time Long-Term Evolution (LTE)-like PHY Time Division Duplex (TDD) mode supports up to 24 spatial streams, providing an...