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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...
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...
A new scheme is offered for minimizing carrier Rayleigh backscattering (CRB) in single feeder fiber based wavelength division multiplexed passive optical network (WDM-PON). The proposed scheme is based on single side band carrier suppressed (SSB-CS)signal, both at network and receiver sides, used for the first time at optical line terminal (OLT) and optical network unit (ONU)sides. We use dual-drive...
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...
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 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...
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...
A novel trellis coded-4×8 overlapping amplitude and pulse position modulation (TC-4×8AOPPM) scheme is proposed to enhance bit error rate (BER) performance of free-space optical communication (FSO) system. In addition, an uncoded AOPPM referential scheme is also designed. The schemes manage to decrease BER by designing gamma-gamma (GG) channel applicable decoding and demodulation methods. Simulation...
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