摘要 :
In this paper, a decode-and-forward (DF) based multiple-input-single-output (MISO) relay assisted dual-hop mixed radio frequency/free space optical (RF/FSO) communication network is considered. Each branch in RF link is assumed to...
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In this paper, a decode-and-forward (DF) based multiple-input-single-output (MISO) relay assisted dual-hop mixed radio frequency/free space optical (RF/FSO) communication network is considered. Each branch in RF link is assumed to experience independent and non-identically distributed (i.n.i.d.) Nakagami- m fading, whereas the irradiance of FSO link is subjected to a Gamma-Gamma distribution with misalignment error (ME). In this work, maximal ratio combining (MRC) diversity scheme at the relay is investigated. The analytical expressions of the probability density function (PDF) and cumulative distribution function (CDF) are derived. Utilizing the derived channel statistics, we obtain the outage probability (OP) and average symbol error probability (SEP) expressions for the considered system.
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摘要 :
In this paper, a decode-and-forward (DF) based multiple-input-single-output (MISO) relay assisted dual-hop mixed radio frequency/free space optical (RF/FSO) communication network is considered. Each branch in RF link is assumed to...
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In this paper, a decode-and-forward (DF) based multiple-input-single-output (MISO) relay assisted dual-hop mixed radio frequency/free space optical (RF/FSO) communication network is considered. Each branch in RF link is assumed to experience independent and non-identically distributed (i.n.i.d.) Nakagami- m fading, whereas the irradiance of FSO link is subjected to a Gamma-Gamma distribution with misalignment error (ME). In this work, maximal ratio combining (MRC) diversity scheme at the relay is investigated. The analytical expressions of the probability density function (PDF) and cumulative distribution function (CDF) are derived. Utilizing the derived channel statistics, we obtain the outage probability (OP) and average symbol error probability (SEP) expressions for the considered system.
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In this paper, a linear adaptive least mean square (LMS) fractionally spaced equalizer (FSE) is proposed to jointly mitigate the severe inter-symbol interference (ISI) and timing jitter encountered by carrierless amplitude and pha...
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In this paper, a linear adaptive least mean square (LMS) fractionally spaced equalizer (FSE) is proposed to jointly mitigate the severe inter-symbol interference (ISI) and timing jitter encountered by carrierless amplitude and phase modulation (CAP) in visible light communication (VLC) systems. The performance of FSE is compared to that of its counterpart, the symbol spaced equalizer (SSE), at the forward error control (FEC) bit error rate (BER) limit. It is shown that at a signal-to-noise ratio (SNR) of 20 dB and FEC BER limit of 3 × 10, FSE is able to achieve a bit rate of 95 Mb/s (spectral efficiency η of 14.6 bits/s/Hz) while only 30 Mb/s (η of 4.6 bits/s/Hz) is possible with SSE using CAP-64. It is observed that the FSE performance is insensitive to timing jitter while SSE performance suffers severe degradation. The results therefore indicate that FSE is better suited for CAP-based VLC systems than the widely used SSE.
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摘要 :
In this paper, a linear adaptive least mean square (LMS) fractionally spaced equalizer (FSE) is proposed to jointly mitigate the severe inter-symbol interference (ISI) and timing jitter encountered by carrierless amplitude and pha...
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In this paper, a linear adaptive least mean square (LMS) fractionally spaced equalizer (FSE) is proposed to jointly mitigate the severe inter-symbol interference (ISI) and timing jitter encountered by carrierless amplitude and phase modulation (CAP) in visible light communication (VLC) systems. The performance of FSE is compared to that of its counterpart, the symbol spaced equalizer (SSE), at the forward error control (FEC) bit error rate (BER) limit. It is shown that at a signal-to-noise ratio (SNR) of 20 dB and FEC BER limit of 3 × 10, FSE is able to achieve a bit rate of 95 Mb/s (spectral efficiency η of 14.6 bits/s/Hz) while only 30 Mb/s (η of 4.6 bits/s/Hz) is possible with SSE using CAP-64. It is observed that the FSE performance is insensitive to timing jitter while SSE performance suffers severe degradation. The results therefore indicate that FSE is better suited for CAP-based VLC systems than the widely used SSE.
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In this paper, we propose a fast dehazing method that is based on a dark channel prior and can automatically be adjusted to the level of haze that needs to be removed. Our method improves the visibility and effectively preserves t...
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In this paper, we propose a fast dehazing method that is based on a dark channel prior and can automatically be adjusted to the level of haze that needs to be removed. Our method improves the visibility and effectively preserves the colors of the original image. Based on the visibility results we can conclude that our method does not introduce noise. Furthermore, our method maintains the speed of the median dark channel prior method introduced in [9]. We also solved the problem of image darkening caused by dehazing. Most importantly, our method shows that processing by the Y channel can improve the structural similarity index measure of restored images. Our method is simple, effective, and fast. We compare our dehazing method with other methods and report on the very successful results.
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摘要 :
In this paper, we propose a fast dehazing method that is based on a dark channel prior and can automatically be adjusted to the level of haze that needs to be removed. Our method improves the visibility and effectively preserves t...
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In this paper, we propose a fast dehazing method that is based on a dark channel prior and can automatically be adjusted to the level of haze that needs to be removed. Our method improves the visibility and effectively preserves the colors of the original image. Based on the visibility results we can conclude that our method does not introduce noise. Furthermore, our method maintains the speed of the median dark channel prior method introduced in [9]. We also solved the problem of image darkening caused by dehazing. Most importantly, our method shows that processing by the Y channel can improve the structural similarity index measure of restored images. Our method is simple, effective, and fast. We compare our dehazing method with other methods and report on the very successful results.
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Multiway Wiener filtering has been inserted in a wavelet framework to enhance spatial details while denoising multidimensional images. An elevated number of rank values is required. A solution is to retrieve the best rank values w...
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Multiway Wiener filtering has been inserted in a wavelet framework to enhance spatial details while denoising multidimensional images. An elevated number of rank values is required. A solution is to retrieve the best rank values while minimizing a mean square criterion. In this paper, we justify the adaptation for this purpose of a stochastic optimization method, and we evaluate comparatively a genetic algorithm and particle swarm optimization. Results obtained on multispectral images in terms of signal to noise ratio and perceptual image quality permit to emphasize the performance of the obtained unsupervised method for realistic noise magnitudes.
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摘要 :
Multiway Wiener filtering has been inserted in a wavelet framework to enhance spatial details while denoising multidimensional images. An elevated number of rank values is required. A solution is to retrieve the best rank values w...
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Multiway Wiener filtering has been inserted in a wavelet framework to enhance spatial details while denoising multidimensional images. An elevated number of rank values is required. A solution is to retrieve the best rank values while minimizing a mean square criterion. In this paper, we justify the adaptation for this purpose of a stochastic optimization method, and we evaluate comparatively a genetic algorithm and particle swarm optimization. Results obtained on multispectral images in terms of signal to noise ratio and perceptual image quality permit to emphasize the performance of the obtained unsupervised method for realistic noise magnitudes.
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Low complexity and spectral efficient carrier frequency offset (CFO) estimation in massive multiple input multiple output (MIMO) systems is a critical problem. Therefore, in this paper we propose a low complexity CFO estimation te...
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Low complexity and spectral efficient carrier frequency offset (CFO) estimation in massive multiple input multiple output (MIMO) systems is a critical problem. Therefore, in this paper we propose a low complexity CFO estimation technique for single carrier frequency domain equalization (SC-FDE) and orthogonal frequency division multiplexing (OFDM) based Massive MIMO systems. In this technique, to increase the spectral efficiency, we use the pilots sent for channel estimation to estimate both the CFO and the channel, iteratively. Our analysis show that our proposed technique has better performance and lower complexity than previous techniques which utilize one pilot block for both CFO and channel estimation in massive MIMO systems.
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摘要 :
Low complexity and spectral efficient carrier frequency offset (CFO) estimation in massive multiple input multiple output (MIMO) systems is a critical problem. Therefore, in this paper we propose a low complexity CFO estimation te...
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Low complexity and spectral efficient carrier frequency offset (CFO) estimation in massive multiple input multiple output (MIMO) systems is a critical problem. Therefore, in this paper we propose a low complexity CFO estimation technique for single carrier frequency domain equalization (SC-FDE) and orthogonal frequency division multiplexing (OFDM) based Massive MIMO systems. In this technique, to increase the spectral efficiency, we use the pilots sent for channel estimation to estimate both the CFO and the channel, iteratively. Our analysis show that our proposed technique has better performance and lower complexity than previous techniques which utilize one pilot block for both CFO and channel estimation in massive MIMO systems.
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