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The handset MIMO antenna is studied by using an in-house developed MIMO system, which can accommodate up to 8 antennas at both Tx and Rx sides. At first, a group of handsets with different number of antennas are designed and fabricated. The mutual coupling and efficiency of the antennas are measured. Then the handsets are inserted into the MIMO system, the channel matrix and throughput achieved by...
In order to enhance the Long Term Evolution (LTE) network performance, the Third Generation Partnership Project (3GPP) introduced Coverage and Capacity Optimisation (CCO) in the context of Self Organising Network (SON). Antenna parameters (i.e. azimuth, electrical tilt etc.) play a key role in CCO and have a significant impact on the users' Quality of Service (QoS). In this paper, a novel metric,...
In this paper, a cooperative cognitive radio network (CRN) with energy harvesting capabilities of its secondary users is considered. Specifically, cooperative spectrum sensing and multi-antenna beamforming are employed to improve the sensing performance and the energy transfer efficiency, respectively. In our approach, a homogeneous CRN scenario is studied where the optimal sensing probability of...
Massive MIMO is the new emerging technology which can be used to increase the data rate. Massive MIMO reap all benefits of conventional MIMO. In Massive MIMO we use the receiver diversity. In this paper we are proposing Opportunistic space division multiple access technology with beam selection for massive MIMO system technology. OSDMA-S is the technology in which we generate a orthonormal beam which...
Broadband technologies are playing a very significant role in the information exchange world. There is a growing trend toward bandwidth-hungry applications driven by data/ video consumption and continuous availability of service. Applications in different areas like in-flight entertainment, maritime connectivity, industrial communications, cellular backhaul via satellite, Internet access to end user,...
Exponential growing of wireless multimedia communications has forced the IEEE802.11 workgroup to define new standard of WLAN. It is named a Very High Throughput WLAN IEEE 802.11ac which exploits MIMO-OFDM technology to provide up to 6,9Gbps of throughput. MIMO decoder is the vital part of WLAN 802.11ac. It decodes the received signals to get back the transmitted information. There are many methods...
Interference coordination in heterogeneous cellular networks is a major bottleneck. In LTE-A (release 10), enhanced inter cell interference coordination (eICIC) scheme is proposed as an effective solution. It notably involves the approach of almost blank subframes (ABS) consisting of muting the macro cell during a set of predefined subframes. This offers the opportunity to the overlay small cells...
We propose a secure transmission scheme for a relay wiretap channel, where a source communicates with a destination via a decode-and- forward relay in the presence of spatially random- distributed eavesdroppers. We assume that the source is equipped with multiple antennas, whereas the relay, the destination, and the eavesdroppers are equipped with a single antenna each. In the proposed scheme, in...
With the explosive growth in wireless usage due in part to smart phones, tablets and a growing applications developer base, wireless operators are constantly looking for ways to increase the spectral efficiency of their networks with low power. Multiple input/ multiple output (MIMO) technology, which made its first broad commercial appearance in IEEE 802.11 systems, is now gaining substantial attention...
In this paper, the wireless information and power transfer performance in amplify-and-forward (AF) relay net- works with multiple antennas is investigated over dissimilar fading channels. The considered network consists of a power transfer/information source, an energy-constrained relay and a destination. The source and the destination are single antenna devices, whereas the relay is equipped with...
Cooperative spectrum sensing has a great impact to increase the performance for detecting the Primary User (PU) signal over single node sensing. Recent developments in multiple antenna techniques adjoin a new dimension in spectrum sensing. In this paper, we have proposed a multi-antenna based signal detection for multi bands considering cooperative approach with Rayleigh fading channel. In addition...
This paper presents outdoor field experimental results to clarify the 4x4 MIMO throughput performance from applying multi-point transmission in the 15 GHz frequency band in the downlink of 5G cellular radio access system. The experimental results in large-cell scenario shows that up to 30 % throughput gain compared to non-multi-point transmission is achieved although the difference for the RSRP of...
This paper presents field experiments on the downlink throughput performance of a beam tracking proof-of-concept system targeting 5G millimeter wave radio access in the following typical small cell environments: a courtyard, lobby, and underground parking area. The majority of the area in the tested environments is Line-Of-Sight (LOS) with cell radii of less than 60 m. The results show that the maximum...
LTE drive tests were conducted in urban and suburban environments with 2×2 MIMO antennas located on the roof and also inside the vehicle. Measurements were conducted at bands 4, 13, and 17. The measured average channel capacities (bits/second) for the antennas placed inside the vehicle were found to be comparable to the measured capacities when the antennas were placed on the roof.
In LTE-A (Long Term Evolution-Advanced) network deployed with higher order MIMO (Multiple Input Multiple Output), CRS (Common Reference Signal) is substituted by CSI-RS (Channel State Information Reference Signal) aiming for detecting channel more efficiently. But LTE (Long Term Evolution) legacy UEs (User Equipment) cannot distinguish CSI-RS from data which may deteriorate the LTE UEs' demodulation...
Optimization of basestation antenna patterns and transmitted powers in heterogeneous 4g networks with geographically inhomogeneous throughput requirements is not an easy problem to tackle, and hence, frequently omitted. Moreover, the initial phase of network dimensioning and planning often fails to meet growing throughput demands, and hence, network operation becomes problematic, especially around...
In this paper, we propose a new single-input multiple-output (SIMO) context-aware cognitive transceiver (CTR) that is able to switch to the best performing modem in terms of link-level throughput and allows to decrease macro transmission power without loosing performances comparing to the conventional Data-aided Least Squares (DA LS) channel estimator. On the top of conventional adaptive modulation...
We present a reconfigurable GPU-based uplink detector for massive MIMO software-defined radio (SDR) systems. To enable high throughput, we implement a configurable linear minimum mean square error (MMSE) soft-output detector and reduce the complexity without sacrificing its error-rate performance. To take full advantage of the GPU computing resources, we exploit the algorithm's inherent parallelism...
We exploit the Degrees of Freedom (DoF) resulting from the deployment of multiple antennas, both at the Access Points (APs) and the clients, to address the Hidden Terminal problem in Multi User (MU) Multiple Input Multiple Output (MIMO)Wireless Local Area Networks (WLANs). This approach permits concurrent transmissions and is able to maintain a constant gain in network throughput in a Hidden Terminal...
The results of design and preliminary open path testing mobile tropospheric communication system are discussed. Practical recommendations to improve the characteristics of quality in mobile tropospheric communications systems are made.
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