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| 2. |
- Persson, Daniel, 1977, et al.
(författare)
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Amplifier-Aware Multiple-Input Multiple-Output Power Allocation
- 2013
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Ingår i: IEEE Communications Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-2558 .- 1089-7798. ; 17:6, s. 1112-1115
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Tidskriftsartikel (refereegranskat)abstract
- We propose multiple-input multiple-output (MIMO) transmitter power allocation which takes dissipation in the power amplifiers into account. We derive the equations of the general problem with full channel state information (CSI), discuss its challenges, and supply solutions in two special cases, namely for a multiple-input single-output channel with a linear beamformer constraint, and for a parallel MIMO channel. The proposed algorithms show substantial gains in terms of rate and total consumed power compared to previous state of the art over a wide range of parameter settings, and have low computational complexities.
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| 3. |
- Persson, Daniel, 1977, et al.
(författare)
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Amplifier-Aware Multiple-Input Single-Output Capacity
- 2014
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Ingår i: IEEE Transactions on Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0090-6778 .- 1558-0857. ; 62:3, s. 913-919
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Tidskriftsartikel (refereegranskat)abstract
- We investigate multiple-input single-output channel capacity taking dissipation in the power amplifiers into account. We consider the case of a fixed channel with full channel state information (CSI) at both the transmitter and receiver. The capacity expression is given on closed form, and we show that the optimal solution is antenna selection. An algorithm for finding minimum consumed power for any given mutual information is further developed, and we show that the powermutual information pair is capacity-achieving. We also investigate the ergodic Rayleigh fading channel with full CSI at the receiver and no instantaneous CSI at the transmitter. We devise a numerical approach which finds the global optimum given a quantization of the space of possible allocated powers. We further show that down to the simulation precision, the ergodic Rayleigh fading solution again is antenna selection. It is shown that the allocation algorithms have low computational complexity and give significant rate and total consumed power gains in comparison to previous state of the art.
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| 4. |
- Persson, Daniel, 1977, et al.
(författare)
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Mixture Model- and Least Squares-Based Packet Video Error
- 2008
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A Gaussian mixture model (GMM)-based spatio-temporal error concealmentapproach has recently been proposed for packet video. The method improvespeak signal-to-noise ratio (PSNR) comparedto several famous error concealment methods, and itis asymptotically optimal when the number of mixture components goes toinfinity.There are also drawbacks however. The estimator has high onlinecomputational complexity,which implies that fewer surrounding pixels to the lost area than desiredare used forerror concealment. Moreover, GMM parameters are estimated withoutconsidering maximization of theerror concealment PSNR.In this paper we propose a mixture-based estimator and a least squaresapproach for solving the spatio-temporal error concealment problem.Compared to the GMM scheme, the new method may base error concealment onmore surrounding pixels to the loss, while maintaining low computationalcomplexity, and model parameters are foundby an algorithm that increases PSNR in each iteration.The proposed method outperforms the GMM-based scheme in terms ofcomputation-performance tradeoff.
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| 5. |
- Persson, Daniel, 1977, et al.
(författare)
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Mixture Model- and Least Squares-Based Packet Video Error Concealment
- 2009
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Ingår i: IEEE Transactions on Image Processing. - 1941-0042 .- 1057-7149. ; 18:5, s. 1048-1054
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Tidskriftsartikel (refereegranskat)abstract
- A Gaussian mixture model (GMM)-based spatio-temporal error concealment approach has recently been proposed for packet video. The method improves peak signal-to-noise ratio (PSNR) compared to several famous error concealment methods, and it is asymptotically optimal when the number of mixture components goes to infinity. There are also drawbacks, however. The estimator has high online computational complexity, which implies that fewer surrounding pixels to the lost area than desired are used for error concealment. Moreover, GMM parameters are estimated without considering maximization of the error concealment PSNR. In this paper, we propose a mixture-based estimator and a least squares approach for solving the spatio-temporal error concealment problem. Compared to the GMM scheme, the new method may base error concealment on more surrounding pixels to the loss, while maintaining low computational complexity, and model parameters are found by an algorithm that increases PSNR in each iteration. The proposed method outperforms the GMM-based scheme in terms of computation-performance tradeoff.
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| 6. |
- Persson, Daniel, 1977, et al.
(författare)
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On Multiple Description Coding of Sources with Memory
- 2010
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Ingår i: IEEE Transactions on Communications. - : IEEE. - 0090-6778 .- 1558-0857. ; 58:8, s. 2242-2251
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Tidskriftsartikel (refereegranskat)abstract
- We propose a framework for multiple description coding (MDC) of sources with memory. A new source coding method for lossless transmission of correlated sources, power series quantization (PSQ), was recently suggested. PSQ uses a separate linear or non-linear predictor for each quantizer region, and has shown increased performance compared to several common quantization schemes for sources with memory. We propose multiple description PSQ as a special case within our framework. The suggested scheme is shown to increase performance compared with previous state-of-the-art MDC methods.
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| 8. |
- Persson, Daniel, et al.
(författare)
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Power Series Quantization for Noisy Channels
- 2010
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Ingår i: IEEE Transactions on Communications. - : IEEE Institute of Electrical and Electronics. - 0090-6778 .- 1558-0857. ; 58:5, s. 1405-1414
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Tidskriftsartikel (refereegranskat)abstract
- A recently proposed method for transmission of correlated sources under noise-free conditions, power series quantization (PSQ), uses a separate linear or nonlinear predictor for each quantizer region, and has shown to increase performance compared to several common quantization schemes for sources with memory. In this paper, it is shown how to apply PSQ for transmission of a source with memory over a noisy channel. A channel-optimized PSQ (COPSQ) encoder and codebook optimization algorithms are derived. The suggested scheme is shown to increase performance compared with previous state-of-the-art methods.
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