2,007,017 research outputs found
Microscopy Conference : MC 2017 Göttingen ; 21 - 25 August 2017, Lausanne, Switzerland: Proceedings
No full textDas Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2017", die vom 21. bis 25.08.2017, in Lausanne stattfand
MC-4C: processing pipeline
No full textThis is a reduced MC-4C dataset provided to be used as a test case for running MC-4C pipeline. The MC-4C pipeline can be freely downloaded from: https://github.com/aallahyar/mc4c_py
Changes compared to original upload:
- Changed name of fastq file from "raw_BMaj-test.fastq" to "fq_BMaj-test.fastq.gz
Partial Equalization for MC–CDMA Systems in Non-Ideally Estimated Correlated Fading
No full textMulticarrier code-division multiple access (MC–CDMA) can support high data rates in next-generation multiuser wireless communication systems. Partial equalization (PE) is a low-complexity technique for combining the signals of subcarriers to improve the achievable performance of MC–CDMA systems in terms of their bit error probability (BEP) and bit error outage (BEO) in comparison with maximal ratio combining, orthogonality restoring combining, and equal-gain combining techniques. We analyze the performance of the multiuser MC–CDMA downlink and derive the optimal PE parameter expression, which minimizes the BEP. Realistic imperfect channel estimation and frequency-domain (FD) block-fading channels are considered. More explicitly, the analytical expression of the optimum PE parameter is derived as a function of the number of subcarriers, number of active users (i.e., the system load), mean signal-to-noise ratio (SNR), and variance of the channel-estimation errors for the aforementioned FD block-fading channel. We show that the choice of the optimal PE technique significantly increases the achievable system load for the given target BEP and BEO
Broadband MC DS-CDMA Using Space-Time and Frequency-Domain Spreading
No full textIn this contribution multicarrier direct-sequence code-division multiple-access (MC DS-CDMA) using space-time spreading (STS) assisted transmit diversity and frequency-domain (F-domain) spreading is investigated in the context of broadband communications over frequency-selective Rayleigh fading channels. We consider the attainable capacity extension of broadband MC DS-CDMA with the advent of using Time-Frequency-domain (TF-domain) spreading. The BER performance of STS assisted broadband MC DS-CDMA using Binary Phase Shit Keying (BPSK) modulation and TF-domain spreading is investigated by simulation for a range of parameter values. Both the correlation based single-user detector and the decorrelating multiuser detector are considered. Our study shows that the number of users supported by the broadband MC DS-CDMA system is determined by the product of the T-domain spreading factor and the F-domain spreading factor, while it is independent of the frequency diversity order. Furthermore, when multiuser detection assisted F-domain spreading is considered, the broadband MC DS-CDMA system is capable of supporting a substantially increased number of users, while maintaining a similar bit error ratio (BER) performance to that of the broadband MC DS-CDMA system using no F-domain spreading
Performance evaluation of carrier interferometry implementations of MC-CDMA over a wideband channel suffering phase noise
No full textIn this paper the performance of Carrier Interferometry (CI) and Pseudo-Orthogonal Carrier Interferometry (PO-CI) [1] implementations of Multi-Carrier Code Division Multiple Access (MC-CDMA) are investigated. Comparisons are made with the performance of traditional MCCDMA (incorporating Hadamard-Walsh spreading codes) [2],[3] and Coded Orthogonal Frequency Division Multiplexing (COFDM) [4]. These systems are simulated over a 20MHz bandwidth, wideband, wide-sense stationary, statistically uncorrelated Rayleigh fading channel suffering additive white Gaussian noise (AWGN) and phase noise. The two channel models employed are consistent with the Model B ‘Indoor and Office’ and Model B ‘Outdoor to Indoor and Pedestrian’ test environment specifications proposed by ETSI for UMTS Terrestrial Radio Access (UTRA) [5]. The BPSK CI system was found to outperform both of the equivalent COFDM and MC-CDMA systems, providing 1dB and 1.5dB performance gains respectively at a bit error rate (BER) of 10-3. The BPSK PO-CI system, shown to offer twice the capacity of the equivalent MC-CDMA, COFDM and CI systems, was found to offer the same performance as MC-CDMA. For higher order modulation schemes, the CI system’s performance was found to equal that of the equivalent MCCDMA system, whilst the performance of PO-CI was found to be very poor. In the presence of phase noise, the CI system was found to outperform the MC-CDMA and COFDM systems, suffering a far lower performance loss for a given level of phase noise and providing a softer fail as this level was increased. This soft fail characteristic was also observed in the PO-CI system
Ant-Colony-Based Multiuser Detection for MC DS-CDMA Systems
No full textIn this contribution we present a novel ant colony optimization (ACO) based multi-user detector (MUD) designed for synchronous multi-carrier direct sequence code division multiple access (MC DSCDMA) systems. The operation of the ACO-based MUD is based on the behaviour of the ant colony in nature. The ACO-based MUD aims for achieving the same bit-error-rate (BER) performance as the optimum maximum likelihood (ML) MUD, without carrying out an exhaustive search of the entire MC DS-CDMA search space constituted by all possible combinations of the received multi-user vectors. We will demonstrate that the system is capable of supporting almost as many users as the number of chips in the spreading sequence, while searching only a small fraction of the entire ML search space. It will also be demonstrated that the number of floating point operations per second is a factor of 108 lower for the proposed ACO-based MUD than that of the ML MUD, when supporting K = 32 users in a MC DS-CDMA system employing 31-chip Gold codes as the T-domain spreading sequence
MC-YOLOv5s training results.
No full textReal-time and accurate detection of ships plays a vital role in ensuring navigation safety and ship supervision. Aiming at the problems of large parameters, large computation quantity, poor real-time performance, and high requirements for memory and computing power of the current ship detection model, this paper proposes a ship target detection algorithm MC-YOLOv5s based on YOLOv5s. First, the MobileNetV3-Small lightweight network is used to replace the original feature extraction backbone network of YOLOv5s to improve the detection speed of the algorithm. And then, a more efficient CNeB is designed based on the ConvNeXt-Block module of the ConvNeXt network to replace the original feature fusion module of YOLOv5s, which improves the spatial interaction ability of feature information and further reduces the complexity of the model. The experimental results obtained from the training and verification of the MC-YOLOv5s algorithm show that, compared with the original YOLOv5s algorithm, MC-YOLOv5s reduces the number of parameters by 6.98 MB and increases the mAP by about 3.4%. Even compared with other lightweight detection models, the improved model proposed in this paper still has better detection performance. The MC-YOLOv5s has been verified in the ship visual inspection and has great application potential. The code and models are publicly available at https://github.com/sakura994479727/datas.</div
MC-YOLOv5s network structure.
No full textReal-time and accurate detection of ships plays a vital role in ensuring navigation safety and ship supervision. Aiming at the problems of large parameters, large computation quantity, poor real-time performance, and high requirements for memory and computing power of the current ship detection model, this paper proposes a ship target detection algorithm MC-YOLOv5s based on YOLOv5s. First, the MobileNetV3-Small lightweight network is used to replace the original feature extraction backbone network of YOLOv5s to improve the detection speed of the algorithm. And then, a more efficient CNeB is designed based on the ConvNeXt-Block module of the ConvNeXt network to replace the original feature fusion module of YOLOv5s, which improves the spatial interaction ability of feature information and further reduces the complexity of the model. The experimental results obtained from the training and verification of the MC-YOLOv5s algorithm show that, compared with the original YOLOv5s algorithm, MC-YOLOv5s reduces the number of parameters by 6.98 MB and increases the mAP by about 3.4%. Even compared with other lightweight detection models, the improved model proposed in this paper still has better detection performance. The MC-YOLOv5s has been verified in the ship visual inspection and has great application potential. The code and models are publicly available at https://github.com/sakura994479727/datas.</div
Sample-Spaced and Fractionally-Spaced CIR Estimation Aided Decision Directed Channel Estimation for OFDM and MC-CDMA
No full textThe achievable performance of decision-directed channel estimation (DDCE) is analysed in the context of both OFDM and MC CDMA systems. Two different estimation methods suitable for both OFDM and MC-CDMA systems are considered, which employ sample-spaced (SS) as well as fractionally-spaced (FS) a posteriori channel impulse response (CIR) estimators. The performance of both estimation methods is compared and it is shown that the DDCE scheme employing the FS-CIR estimator outperforms its SS-CIR estimator-based counterpart. Furthermore, the FS-CIR estimator-based method exhibits higher robustness to various channel parameters such as the channel’s root mean square delay spread. Finally, it is shown that the MC-CDMA system employing the channel estimation scheme advocated outperform its OFDM counterpart
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