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Downlink Carrier Aggregation is a promising LTE-Advanced technology which is introduced in 3GPP LTE Release 10. Meanwhile, it introduces some challenges since more uplink control information needs to be fed backed from UE to eNB to enable the carrier aggregation. In this paper, we firstly introduce the CA feature in LTE-Advanced, and present the PUCCH format 1b with channel selection and PUCCH format...
A modified double sideband modulation(DSB) scheme to realize frequency doubling and wavelength reuse in the uplink is proposed. In the modified DSB scheme, by adjusting the phase difference between two arms of the intensity modulator, the optical carrier and the two first-order sidebands are generated, after beaten by the photodiode, a high spectrum purity and low phase noise millimeter-wave (mm-wave)...
In the fiber optic perimeter security system, which is based on Mach-Zehnder interferometer, the human intrusion and partial environmental noise can cause the fiber vibration. Distinguishing intrusion from environmental events without reducing the efficiency is a key requirement for any perimeter intrusion detection systems. In this paper, an signal classification system is presented for detection...
Ethernet-based passive optical network (EPON) is a cost-effective optical access technology, which can provide massive bandwidth and smooth connection with legacy Ethernet networks. Due to limited uplink bandwidth, bursty and unstable traffic load, EPONs may fail to provide sufficient bandwidth to meet the bandwidth requirement of all users. Pursuing fairness of bandwidth distribution and maximization...
In a full duplex transceiver, which transmits and receives simultaneously at the same frequency, since the self-interference from the transmitted antenna to the received antenna is strong, the self-interference cancellation in the analog domain is required. However, subject to the limited accuracies of devices, the theoretical analysis of the analog self-interference cancellation has a large difference...
We numerically investigate the time delay signature (TDS) properties of a chaotic semiconductor laser subject to nonlinearly-modulated feedback. In the proposed scheme, two semiconductor lasers that play the role of a built-in nonlinear modulator is positioned in the external cavity of the chaos generator laser, which forms a structure of semiconductor laser ring. The simulation results show that...
For M-ary spread spectrum (MSS) communication systems with orthogonal frequency division multiplexing (OFDM) technique, a simple scheme to generate lots of MSS sequences is presented on the basis of circular shift and selection operation. The number of the generated sequences is far larger than sequence length at the cost of the decreased correlation property, which is significantly important to improve...
There is severe Doppler shift in satellite optical communication, which greatly affects the coherent demodulation and should be eliminated. This paper is a preliminary study of the optical phase-locked loop, using the broadcast ephemeris to estimate the Doppler shift and pulling it down into a range in which it can be captured by digital processing. A comparison is made between the Doppler shift estimation...
Based on the exponentiated Weibull distribution of scintillations, transmit lasers selection combining (SC) method, intensity modulation/ direct detection with on-off keying modulation, the optimization of an adaptive tracking free-space optical (FSO) communication link with single-input multiple-output (SIMO) is investigated. The closed-form mathematical expression for average bit error rate is derived...
A linear phase-modulated photonic link based on optical carrier band (OCB) processing is proposed. By introducing a proper phase shift to the OCB, the third-order intermodulation distortion (IMD3) component of the signal transmitted over a length of fiber is effectively power faded, while the fundamental component is almost maintained. The IMD3 is effectively suppressed to realize a linear phase-modulated...
Mobile sink plays a pivotal role for data collection in wireless sensor networks (WSNs). But, sensor nodes close to mobile sink are bound to change their routes to Base Station(BS) or mobile sink frequently. As a result, they will generate excessive energy consumption of sensors and cause a very large delivery delay. In this paper, an energy-efficient mechanism for data collection based on single...
In this paper, the transmission schemes for Centralized Radio Access Network Architecture (C-RAN) based on combination of two technologies - Radio over Fiber (RoF) and Radio over FSO (RoFSO) are simulated and experimentally verified. The proposed setups are optimized for Long Term Evolution (LTE) with 20 MHz bandwidth using 64 Quadrature amplitude modulation in terms of Error Vector Magnitude (EVM)...
In the well-recognized cloud radio access networks concept, radio-over-fiber (ROF) links can serve as an option to make fronthaul connections conveying multi-band radio signals. High-performance ROF links covering future higher frequency commonly rely on external modulation. However, externally-modulated ROF links suffer from inherent modulator nonlinearities. In order to address this issue, we investigated...
A self-reference method for measuring the magnitude frequency response of optical filters is proposed based on nested heterodyne interferometer, which enables high-resolution measurement in the electrical domain with doubled measuring frequency range.
To increase the throughput and performance of the next-generation wireless cellular network, this paper proposes two clustering algorithms for integrated cellular and ad hoc relaying systems. In this system, we consider that all the available users are divided into two groups: One is the super group which locates in the cell central region, and another is the regular group which locates in the cell...
Acquisition module is an important part in GPS receiver. Three current acquisition methods are introduced, and on the basis of parallel frequency search, a new algorithm that changing step length and quadratic curve fitting in frequency domain is given to improve the precision of acquisition. At the same time, parallel frequency search and parallel code phase search are combined to implement code...
Consider the diversity of users' traffic types, we investigate the problem of distributed carrier aggregation in cognitive small cell networks. In most existing carrier aggregation (CA) researches, they aimed to optimize the throughput or to mitigate the interference. However, in practical wireless communication users' quality of experience (QoE) is the ultimate concerning. Different QoE functions...
A novel operation mode field reconfigurable DBR laser is designed, realized and investigated experimentally. With different controlling of the same hardware, a shared-cavity six-section DBR laser diode can be flexibly configured to operate as a continuous wave or a pulsed wave laser.
Zigbee is a famous wireless communication system for its many advantages. The Co-channel interference (CCI) is a main interference to Zigbee network. The CCI in Zigbee system can be divided into two types. One comes from other wireless communication technology, for example, Bluetooth, WiFi. Another comes from other Zigbee wireless network. The paper main works conclude simulating Zigbee system based...
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