G.718: A new embedded speech and audio coding standard with high resilience to error-prone transmission channels

Jelinek, Milan; Vaillancourt, Tommy; Gibbs, Jon

doi:10.1109/mcom.2009.5273818

Cited by 15 publications

(3 citation statements)

References 5 publications

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“…Unlike the superwideband extensions for G.711.1 and G.722, G.729.1 Annex E does not split the input using a PQMF bank. Instead, G.729.1 Annex E employs essentially the same algorithm used to extend ITU-T Recommendation G.718 [24], [25] for superwideband input [26,Annex B]. The 32 Ksps input is antialias-filtered using an IIR lowpass filter and subsampled to 16 Ksps for input to the G.729.1/G.718 core wideband encoders.…”

Section: Background On Multirate Filter Banks In Digital Coding Smentioning

confidence: 99%

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Group-Theoretic Structure of Linear Phase Multirate Filter Banks

Brislawn

2013

IEEE Trans. Inform. Theory

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Unique lifting factorization results for group lifting structures are used to characterize the grouptheoretic structure of two-channel linear phase FIR perfect reconstruction filter bank groups. For Dinvariant, order-increasing group lifting structures, it is shown that the associated lifting cascade group C is isomorphic to the free product of the upper and lower triangular lifting matrix groups. Under the same hypotheses, the associated scaled lifting group S is the semidirect product of C by the diagonal gain scaling matrix group D. These results apply to the group lifting structures for the two principal classes of linear phase perfect reconstruction filter banks, the whole-and half-sample symmetric classes. Since the unimodular whole-sample symmetric class forms a group, W, that is in fact equal to its own scaled lifting group, W = S W , the results of this paper characterize the group-theoretic structure of W up to isomorphism. Although the half-sample symmetric class H does not form a group, it can be partitioned into cosets of its lifting cascade group, C H , or, alternatively, into cosets of its scaled lifting group, S H . Homomorphic comparisons reveal that scaled lifting groups covered by the results in this paper have a structure analogous to a "noncommutative vector space."

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Section: Background On Multirate Filter Banks In Digital Coding Smentioning

confidence: 99%

“…In either case, the scaling matrices are D K = I = D K so application of [5, Theorem 1] to ( 22)-( 23) or ( 24)- (25) shows that N = N and S i (z) = S i (z) for i = 0, . .…”

Section: B Free Products Of Groupsmentioning

confidence: 99%

Group-Theoretic Structure of Linear Phase Multirate Filter Banks

Brislawn

2013

IEEE Trans. Inform. Theory

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“…Although, the reference HCCA schedules traffics upon their negotiated QoS requirements in the first place, it is only efficient for CBR applications such as CBR G.711 [10] audio streams and H.261 [11] video (MPEG-1). However, it is not convenient to deal with the fluctuation of the VBR traffic such as H.263 [12] video streams and G.718 [13] audio traffic, where neither the packet size nor the packet generation time is constant. This consequently leads to a remarkable increase in the end to end delay of the delivered traffics and degradation in the channel bandwidth utilization as well.…”

Section: Introductionmentioning

confidence: 99%

Feasible HCCA Polling Mechanism for Video Transmission in IEEE 802.11e WLANs

Al-Maqri

Othman

Ali

et al. 2015

Wireless Pers Commun

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IEEE 802.11e standard defines two Medium Access Control (MAC) functions to support Quality of Service (QoS) for wireless local area networks: Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA provides fair prioritized QoS support while HCCA guarantees parameterized QoS for the traffics with rigid QoS requirements. The latter shows higher QoS provisioning with Constant Bit Rate (CBR) traffics. However, it does not efficiently cope with the fluctuation of the Variable Bit Rate (VBR) video streams since its reference scheduler generates a schedule based on the mean characteristics of the traffic. Scheduling based on theses characteristics is not always accurate as these traffics show high irregularity over the time. In this paper, we propose an enhancement on the HCCA polling mechanism to address the problem of scheduling pre-recorded VBR video streams. Our approach enhances the polling mechanism by feed-backing the arrival time of the subsequent video frame of the uplink traffic obtained through cross-layering approach. Simulation experiments have been conducted on several publicly available video traces in order to show the efficiency of our mechanism. The simulation results reveal the efficiency of the proposed mechanism in providing less delay and high throughput with conserving medium channel through minimizing the number of Null-Frames caused by wasted polls.

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