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There are some shortcomings in the delay tolerant network (DTN) routing algorithm, such as low message delivery rate, low network efficiency and high cost in the satellite network. In order to solve the problem above, this paper proposes a limited copy algorithm MPWLC based on service probability. In MPWLC, not only is the number of copies limited, but the storage resources of the satellite are also...
In this paper, a novel polarization mode dispersion (PMD) monitoring method by adding auxiliary optical signal is presented. Based on four-wave mixing (FWM), the PMD can be monitored in all-optical domain by measuring the power of the idler wave. With the help of auxiliary signal, the change trend of idler wave power with PMD will be enlarged, which expands the scope of monitoring and improves the...
As in-line interference between geostationary(GEO) and Non-Geostationary(NGEO) systems is becoming more and more serious. We propose an efficient utilisation of the adaptive modulation and coding (AMC) scheme for spectral coexistence of GEO and NGEO satellites to mitigate in-line interference. Results of Simulation show that the proposed scheme can improve the performance of the NGEO system in comparison...
In this paper, a novel Cross-layer Dynamic Bandwidth Allocation Algorithm Based on Convex Optimization Theory(CO-CDBA) in Digital Video Broadcast-Return Channel via Satellite system is proposed. A novel utility function by taking application layer, Data Link Layer and physical layer(PHY) parameters into account is established. The Dynamic Bandwidth Allocation(DBA) problem is converted to a convex...
In order to solve the problem of instability clustering in Ad Hoc Networks with complex and changeable node motion, this paper proposes a weighted clustering algorithm based on node stability(SA-WCA). In this algorithm, we propose a node stability factor based on node received power, which does not need to calculate the specific distance between nodes and can only judge the relative motion between...
We demonstrated a dense sub-carrier uniform division labeling transmission system by using MATLAB software. The simulation results indicated that dense sub-carrier uniform division labeling has a good advantage over that ordinary OFDM system, and the signals at a bit rate 50Gbit/s have a good performance which is more than 10 when OSNR is equal to 25dB over 1000km optical fiber channel which only...
In this paper, a novel phase noise estimation method (PNE) for multi-level modulations is proposed based on local optimization (LO PNE). The effectiveness of this method is demonstrated and discussed in a 200G bit/s coherent transmission system. It has been proved, the usage of throwing-point (TP) test rotation and convex programming in LO_PNE reduce the complexity of phase estimation for arbitrary...
In this paper we present a decision feedback channel estimation way for the mobile satellite communication system in order to improve the bit error performance. The transmission is disturbed not only by shadowing and multipath effects and additive white Gaussian noise, but also by the weather attenuation. The conventional Least Square(LS) is not well suited to detect the transmitter sequence, whereas...
In this paper, we have proposed an optical pulse position modulation based on double-circle iteration, targeting at the next generation of high speed optical metropolitan area networks. The focuse of this paper lies on the performance of spectral efficiency, the bit error rate and chromatic dispersion. The proposed modulation format is also compared to on-off-keying(OOK) and 4-level pulse-amplitude...
Passive Optical Network (PON) is the most promising technology in optical access network, and the effective and reasonable upstream dynamic bandwidth allocation (DBA) is the key. This paper proposes a new software defined WDM-TDM PON frame that enable more users to share a single high-capacity fiber access as well as introduce a flexible DBA module to replace the hardware-configured DBA module. The...
In order to solve the problem of on-board optical burst switching assembly algorithm cannot realize completely QoS guarantee, an on-board optical burst switching weight-weighted round robin assembly algorithm based on the QoS guarantee(QWRRA) is proposed in this paper. In this assembly algorithm, IP packet will be inserted in different queue according to the different destination and QoS level when...
In this paper we consider a novel design of space-time block code combined with pre-coding module transmission system. Theory of orthogonal designs has shown that such code cannot be simultaneously orthogonal, of rate 1, with full diversity order, for more than 2 transmit antennas. We propose in this paper a new way to overcome this limitation by adding a pre-coding module before transmitting space-time...
We propose a first-order Polarization Mode Dispersion (PMD) monitoring technique for phase-modulated optical signals utilizing the cross-phase modulation (XPM) effect between the input signal and the inserted continuous-wave probe in parallel connection. Because of accumulation of PMD, the XPM effect in nonlinear fiber leads to variation of pump phase. This can cause spectrum broadening resulting...
An efficient modulation and coding scheme combined with multiple LDPC codes and PPM modulation is proposed to mitigate the effect of atmospheric turbulence, which can have an unfavorable impact on the reliability of the communication link in the laser channel of the integration network of satellite and ground. The research is mainly about the reliability of the communication link under different orders...
We put forward and simulation demonstrated a multi-broadband radio over fiber (RoF) system based on Generalized Frequency Division Multiplexing (GFDM) by the using of Matlab software to call OptiSystem. The system simultaneously transmits four GFDM signals modulated to four different carriers. Each signal is with bit rate 10Gbit/s and bandwidth 2.5GHz and carriers are with frequency 10, 13, 16 and...
We demonstrated a direct-modulated multiple formats optical OFDM system based on Discrete Wavelet Transform by using MATLAB software. The simulation results indicated that DWT-OFDM has a good advantage over FFT-OFDM, and the signals at a bit rate 5Gbit/s have a good performance which is nearly equal to 10−3 when OSNR is equal to 25dB over 300km optical fiber channel which only concerns the influence...
A cross-layer based ant colony optimization (ACO) for routing and wavelength assignment (RWA) algorithm (CL-ACORWA) in an optical satellite network is proposed. The main objective is to enhance the network robustness. At first, a cross-layer optimization model is designed, which considers the Doppler wavelength shift of the physical layer and the transmission delay of the network layer. Then an ant...
The convergence of optical and wireless network has led to the trend of future access network . Under the study of Software Defined Radio Access Network(SD-RA) and Soft Frequency Reuse(SFR) system model, this paper presents a new inter-cell interference suppression algorithm of SD-RA network. The paper also summarizes and analyses the difference between the SFR based on coordinate multi-point transmission...
In order to solve the problem of introducing additional Total Degradation (TD) in adaptive satellite system caused by fixed High Power Amplifier (HPA) operating point, the paper proposes an adaptive HPA Input Back-Off (IBO) algorithm carried out on the gateway side in the Forward Link of the system based on Adaptive Coding and Modulation (ACM) techniques. On the other hand, the traditional way of...
This paper presented a multi-rate Star-QAM encoding and decoding method based on the hierarchical coding which could be adjusted to achieve the channel coding efficiency and modulation. The design is based on the combination of soft / hard decision in layered decoding. We have successfully increased BER performance to 0.5dB which achieved 10−5 when SNR is 11 compared to no stratification codec considering...
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