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This paper proposes a fast and low-complexity retransmission scheme for Industrial WLAN system. The proposed scheme exploits the frequency diversity and employs channel selectivity in order to achieve high-reliability and low-latency communication. The channel selectivity is carried out instantly by re-scheduling sub-carrier allocation during OFDM transmission in order to obtain diversity gain. Evaluation...
Orthogonal Frequency division multiplexing is the modulation technique used for the fourth generation wireless communication system. In OFDM, Signals can be modulated by multiple carriers. OFDM uses the bandwidth of the spectrum efficiently. But the limitation of the OFDM system is the high Peak to Average Power Ratio (PAPR) which results in the degradation of the signal quality. Hence reducing the...
Advanced wireless radio standards set stringent requirements on the bandwidth, frequency range and reconfigurability of base-station transmitters. Recently, the outphasing concept has shown promise of wide bandwidth while taking advantage of process scaling with extensive exploitation of rail-to-rail signaling. Recent outphasing transmitter designs have often focused on power-amplifier (PA) and power-combiner...
For the first time, real-time 2-Dimensional localization and velocity measurements using simultaneous 4×4 transmit and receive antenna configuration with an OFDM Radar implemented on commercially available Software Defined Radios (SDR) are presented. The Radar setup uses 100MHz bandwidth at 4.05 GHz to achieve a range resolution of 1.5 m, and the integration time of 11.8 ms to obtain a velocity resolution...
The 3GPP standardization process for the fifth generation of wireless networks, 5G, has been in full gear since early 2016. Perhaps one of the most ambitious standardization goal in wireless history; encompassing diverse characteristics such as massive broadband connectivity, massive (and densely) connected devices, and ultra reliable and low latency connection. In this paper, we review the progress...
The rapid growth in world-wide communications and the rapid adoption of the Internet has significantly modified our way of life. The traffic behavior is changing rapidly and the increasing mobility of traffic sources makes grooming more complex. To fulfill the needs of the future Internet, optical transmission and networking technologies are moving toward to the goals of greater efficiency, flexibility,...
It is proposed that both digital and analog predistortion (DPD, APD) be used to cancel intermodulation distortion (IMD) in a dual band transmitter. DPD reduces IMDs near the carrier frequencies whereas APD cancels IMDs located at multiples of the carrier frequency separation. It is shown that linearization using memoryless basis waveforms provides cancellation of the dominant IMD modes when the two...
Long Term Evolution Advanced (LTE-A) is the fourth generation (4G) wireless cellular communication standard. A covert channel is a noticeable threat to network security because it is able to transfer data under the overt channel. In this paper, a new class of covert channel coined as SNsteg is proposed, designed for LTE-A system. The SNsteg peculiarly utilizes the feature of Sequence Number (SN) fields...
The SLICE architecture for a 6-node network with its components is analyzed. Balanced load spectrum allocation and shortest path with maximum reuse are simulated to address the routing and spectrum allocation. The algorithms results show the reduction in sub-carrier utilization in a SLICE optical network. The simulation results also gives us the maximum subcarriers utilized in each case for various...
Unlimited voice services no longer command premium pricing, but are viewed as “table stakes” in a broader service offering that must now include multimedia (voice, data, video) communications with a mobility component. As a result of this shift, many service providers are trying to adopt, Long Term Evolution (LTE) network strategy to deliver this multimedia experience to their subscribers [1]. Today,...
This paper proposes a methodology to reduce Packet Error Rate (PER) of a Very High Throughput (VHT) physical layer frame in a WiFi Direct (WD) 802.11ac Wireless Local Area Network (WLAN) by examining the loss of individual fields. To this end, a 2x2 Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing (MIMO-OFDM) transceiver is implemented under a TGn multipath fading channel...
Spectral efficiency and energy efficiency are important design criteria for green communications. In this paper, spectral efficiency and energy efficiency are addressed for transmission over channels that are orthogonal in frequency. The maximum sum rate is used in measuring the spectral- and energy-efficiency. The combined spectral- and energy-efficiency of particular total bandwidth and total transmit...
In this paper, we propose an indoor positioning system (IPS) that achieves centimeter accuracy in a complex indoor environment using time-reversal (TR) technique with a single pair of off-the-shelf multi-antenna WiFi devices. The proposed IPS can work under both line-of-sight (LOS) and non-line-of-sight (NLOS) environment. Leveraging the spatial diversity on the multi-antenna WiFi device, the proposed...
This paper investigates the application of flexible and effective fast-convolution (FC) filtering scheme for multiplexing OFDM physical resource blocks (PRBs) in a spectrally well-localized manner. The scheme is able to suppress interference leakage between adjacent PRBs, thus supporting independent waveform parametrization for different PRBs, as well as asynchronous multiuser operation. These are...
In practice, wireless nodes may have different mobility and/or different scattering environment leading to disparity in coherence time and/or coherence bandwidth. Coherence diversity, as a novel source of gain, exploits fading condition disparity of different nodes to provide gain. Downlink transmission for two wireless nodes is considered in three scenarios of fading conditions disparity: in coherence...
This paper proposes a novel and simple orthogonal faster than Nyquist (OFTN) data transmission and detection approach for a single input multiple output (SIMO) system. It is assumed that the signal having a bandwidth is transmitted through a wireless channel having multipath components. Under this assumption, the current paper provides novel OFTN transmission and symbol-by-symbol detection approach...
Visible light communications (VLC) technology has recently emerged as a complementary technology to the indoor radio frequency (RF) networks. While the backhauling of the indoor RF networks has been supported by fiber optics, the backhauling of the VLC network is still an open research problem. Power line communications (PLC) has been considered as a possible solution for the VLC networks due to its...
Unique word orthogonal frequency division multiplexing (UW-OFDM) is based on introducing redundancy, either on dedicated redundant subcarriers leading to systematically encoded UW-OFDM, or spread over the entire bandwidth resulting in the non-systematically encoded UW-OFDM concept. The waveform design of the latter has originally been optimized by incorporating transmitter and receiver processing...
User association and resource allocation for downlink orthogonal frequency division multiplexing (OFDM) should be jointly optimized in small cells networks with limited backhaul in order to maximize the network utility. In general, the joint user association and per-band resource allocation problem is known as an integer NP-hard problem requiring exponential order of computational complexity to find...
Orthogonal Frequency Division Multiplexing (OFDM) technique is widely used due to its high spectrum efficiency. It is used as physical layer standard in 802.11a WLAN standard & Digital Video Broadcasting-Terrestrial (DVB-t). The Fourth generation wireless communication standards are based of OFDM. Traditionally, Fast Fourier Transforms (FFT) has been used to produce the orthogonal sub-carriers...
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