Power minimization under real-time source distortion constraints in wireless networks

Kwasinski, Alexis; Han, Zhu; Liu, K.J.R.; Farvardin, N.

doi:10.1109/wcnc.2003.1200405

Cited by 9 publications

(7 citation statements)

References 9 publications

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“…As we can see from the figure, the approximation in (13) is a good approximation for the qualitative behavior of the practical voice encoder, as well. Notice that the curve of the GSM-AMR NB coder simulations differs from 2 It is worthy of mention that the encoders in transmitters still encode according to the distortion defined in (5).…”

Section: Simulation Resultsmentioning

confidence: 99%

“…Since the constraint is satisfied by the approximation in (13), the optimization goal in (14) is equal to minimize . From (2), the overall power that satisfies can be written in a matrix form [5] …”

Section: B Pizza Party Algorithmmentioning

confidence: 99%

“…In [4], the problems of resource allocation in CDMA were studied for different performance goals. In [5], the overall power was minimized for uplink multicell multimedia systems. In [6] and [7], the system was optimized by defining a utility which was maximized by dynamic pricing and cooperation between mobiles and base stations.…”

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confidence: 99%

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A Near-Optimal Multiuser Joint Speech Source-Channel Resource-Allocation Scheme Over Downlink CDMA Networks

2006

IEEE Trans. Commun.

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Abstract-In downlink of code-division multiple-access (CDMA) networks, the maximal number of real-time calls can be increased by smoothly increasing the end-to-end distortions. In this paper, a cross-layer optimization system is developed to control each user's distortion by adapting source coding rates, channel coding rates, and transmit powers. In addition, the channel-induced distortion is controlled to be only a small proportion of the total end-to-end distortion, such that the subjective quality of the received signal is high. The formulated problem is to reduce the overall end-to-end distortion in downlink single-cell systems, under the constraints of users' maximal acceptable distortions and maximal total transmit power from the base station. To solve this problem, a near-optimal algorithm is constructed to allocate resources. A performance upper bound is developed and compared with the performance of the proposed algorithm. A dynamic system considering speech activities and different offered loads is also analyzed. From the simulation results, the proposed algorithm significantly reduces distortion and the necessary maximal transmit power when the number of users is large, compared with the traditional voice over CDMA schemes.

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Section: Simulation Resultsmentioning

confidence: 99%

Section: B Pizza Party Algorithmmentioning

confidence: 99%

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A Near-Optimal Multiuser Joint Speech Source-Channel Resource-Allocation Scheme Over Downlink CDMA Networks

2006

IEEE Trans. Commun.

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“…The R-D function for SD source encoders is frequently considered to be of the form R ¼ ð1=c 2 Þ logðc 1 =DÞ, where we are taking the logarithm with base e, and hence, R, the source encoding rate, is measured in nats per channel use. This form of R-D function can approximate or bound a wide range of practical systems such as video coding with an MPEG codec [20], speech using a CELP-type codec [21], or when the high rate approximation holds [6]. Assuming that highresolution approximation can be applied to the source encoding operation, each of the input samples can be modeled as a memoryless Gaussian source, showing a zero mean, unit-variance Gaussian distribution.…”

Section: System Modelmentioning

confidence: 99%

Asymptotic Distortion Performance of Source-Channel Diversity over Multihop and Relay Channels

Seddik

Kwasinski

Liu

2010

IEEE Trans. on Mobile Comput.

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A key challenge in the design of real-time wireless multimedia systems is the presence of fading coupled with strict delay constraints. A very effective answer to this problem is the use of diversity achieving techniques to overcome the fading nature of the wireless channels caused by the mobility of the nodes. The mobility of the nodes gives rise to the need of cooperation among the nodes to enhance the system performance. This paper focuses on comparing systems that exhibit diversity of three forms: source coding diversity, channel coding diversity, and user cooperation diversity implemented through multihop or relay channels with amplifyand-forward or decode-and-forward protocols. Commonly used in multimedia communications, performance is measured in terms of the distortion exponent, which measures the rate of decay of the end-to-end distortion at asymptotically high signal-to-noise ratio (SNR). For the case of repetition coding at the relay nodes, we prove that having more relays is not always beneficial. For the general case of having a large number of relays that can help the source using repetition coding, the optimum number of relay nodes that maximizes the distortion exponent is determined in this paper. This optimum number of relay nodes will depend on the system bandwidth as well as the channel quality. The derived result shows a trade-off between the quality (resolution) of the source encoder and the amount of cooperation (number of relay nodes). Also, the performances of the channel coding diversity-based scheme and the source coding diversity-based scheme are compared. The results show that for both relay and multihop channels, channel coding diversity provides the best performance, followed by the source coding diversity.

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“…The D-R function for SD source codecs is frequently considered to be of the form D S (R S ) = c . This form of D-R function can approximate or bound a wide range of practical systems such as video coding with an MPEG codec [10], speech using a CELP-type codec [11], or when the high rate approximation holds. Assuming that each of the input signal samples are memoryless, following a zero-mean, unit-variance Gaussian distribution and if long block source codes are used, we have c 1 = 1, c 2 = 2 ( [12]).…”

Section: System Modelmentioning

confidence: 99%

On QoS constraints and joint source-channel coding for real-time cooperative multimedia communications

Kwasinski

Zhao

Liu

2006

IEEE Wireless Communications and Networking Conference, 2006. WCNC 2006.

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Abstract-Cooperative diversity exploits the broadcast nature of wireless channels by allowing users to relay information for each other so as to create multiple signal paths. This technique could be used together with joint source-channel bit rate allocation to transmit conversational multimedia traffic. This paper studies, following a methodology that avoids the use of high or low SNR approximations, the interaction between joint source-channel bit rate allocation with AF and DF cooperation. Furthermore, the effect of QoS constraints on performance is studied. In addition to the advantages of user-cooperation at medium and low source-destination channel Signal-to-Noise ratio, the results in this paper point at the fact that significant extra performance gains could be obtained by careful selection of the relay node. Guidelines for choosing the relay are also discussed.

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Power minimization under real-time source distortion constraints in wireless networks

Cited by 9 publications

References 9 publications

A Near-Optimal Multiuser Joint Speech Source-Channel Resource-Allocation Scheme Over Downlink CDMA Networks

A Near-Optimal Multiuser Joint Speech Source-Channel Resource-Allocation Scheme Over Downlink CDMA Networks

Asymptotic Distortion Performance of Source-Channel Diversity over Multihop and Relay Channels

On QoS constraints and joint source-channel coding for real-time cooperative multimedia communications

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