Speeding up Future Video Distribution via Channel-Aware Caching-Aided Coded Multicast

Future Internet usage will be dominated by the consumption of a rich variety of online multimedia services accessed from an exponentially growing number of multimedia capable mobile devices. As such, future Internet designs will be challenged to provide solutions that can deliver bandwidth-intensive, delay-sensitive, on-demand video-based services over increasingly crowded, bandwidth-limited wireless access networks. One of the main reasons for the bandwidth stress facing wireless network operators is the difficulty to exploit the multicast nature of the wireless medium when wireless users or access points rarely experience the same channel conditions or access the same content at the same time. In this paper, we present and analyze a novel wireless video delivery paradigm based on the combined use of channel-aware caching and coded multicasting that allows simultaneously serving multiple cache-enabled receivers that may be requesting different content and experiencing different channel conditions. To this end, we reformulate the caching-aided coded multicast problem as a joint source-channel coding problem and design an achievable scheme that preserves the cache-enabled multiplicative throughput gains of the error-free scenario,by guaranteeing per-receiver rates unaffected by the presence of receivers with worse channel conditions.Comment: 11 pages,6 figures,to appear in IEEE JSAC Special Issue on Video Distribution over Future Interne

Method and system for a reduced-complexity scheduling for a network MIMO with linear zero-forcing beamforming

Example embodiments are directed toward a system and a method for downlink scheduling in a multi-user, multiple-input and multiple-output (MU-MIMO) network with a central controller employing a scheduling scheme pre-selecting user equipment according to probabilities obtained from a large-system analysis. Only pre-selected user equipment is requested to feedback channel state information, thereby reducing cluster interference and increasing throughput while greatly reducing the required feedback channel state information generally required to schedule transmission

Interference cancellation method and receiver

The invention relates to an interference cancellation method and a receiver including interference canceller for suppressing a narrow-band interference signal from a received signal, converter for performing an orthonormal conversion of the signal into subspace components of a desired subspace, a decoder connected operationally to the output of the interference canceller, in which decoder an estimate for the received signal is obtained. The output of the decoder is operationally connected to the interference canceller, and the converter is arranged to determine an estimate for narrow-band interference properties, in which determination the estimate obtained from the output of the decoder is subtracted from the received signal before the orthonormal conversion is performed. By using the determined estimate, the interference canceller is arranged to reduce effect of the subspace components including narrow-band interference signals from the received signal

Interference cancellation method and receiver

The invention relates to an interference cancellation method and a receiver including interference canceller for suppressing a narrow-band interference signal from a received signal, converter for performing an orthonormal conversion of the signal into subspace components of a desired subspace, a decoder connected operationally to the output of the interference canceller, in which decoder an estimate for the received signal is obtained. The output of the decoder is operationally connected to the interference canceller, and the converter is arranged to determine an estimate for narrow-band interference properties, in which determination the estimate obtained from the output of the decoder is subtracted from the received signal before the orthonormal conversion is performed. By using the determined estimate, the interference canceller is arranged to reduce effect of the subspace components including narrow-band interference signals from the received signal

Asymptotic Analysis of Improved Linear Receivers for BPSK-CDMA Subject to Fading

In this paper, we design and analyze a new class of linear multiuser detectors, which can be applied when the users employ BPSK modulation and the fading coefficients of the active users are known at the receiver (such as base-station demodulation) . The tools of asymptotic distribution of the spectrum of large random matrices are used to show that relative to the classical minimum mean-square-error (MMSE) receiver, the output signal-to-noise ratio (SNR) improves by halving the number of effective interferers and adding 3 dB to the input SNR. We also propose sensible approximations to the proposed linear receivers so as to facilitate their use in CDMA systems that employ long codes

The Shannon Transform in Random Matrix Theory

The landmark contributions to the theory of random matrices of Wishart (1928), Wigner (1955), and Marcenko and Pastur (1967), were motivated to a large extent by their applications. In this paper we report on a new transform motivated by the application of random matrices to various problems in the information theory of noisy communication channels