3,035 research outputs found

    Asymptotic Error Free Partitioning over Noisy Boolean Multiaccess Channels

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    In this paper, we consider the problem of partitioning active users in a manner that facilitates multi-access without collision. The setting is of a noisy, synchronous, Boolean, multi-access channel where KK active users (out of a total of NN users) seek to access. A solution to the partition problem places each of the NN users in one of KK groups (or blocks) such that no two active nodes are in the same block. We consider a simple, but non-trivial and illustrative case of K=2K=2 active users and study the number of steps TT used to solve the partition problem. By random coding and a suboptimal decoding scheme, we show that for any T(C1+ξ1)logNT\geq (C_1 +\xi_1)\log N, where C1C_1 and ξ1\xi_1 are positive constants (independent of NN), and ξ1\xi_1 can be arbitrary small, the partition problem can be solved with error probability Pe(N)0P_e^{(N)} \to 0, for large NN. Under the same scheme, we also bound TT from the other direction, establishing that, for any T(C2ξ2)logNT \leq (C_2 - \xi_2) \log N, the error probability Pe(N)1P_e^{(N)} \to 1 for large NN; again C2C_2 and ξ2\xi_2 are constants and ξ2\xi_2 can be arbitrarily small. These bounds on the number of steps are lower than the tight achievable lower-bound in terms of T(Cg+ξ)logNT \geq (C_g +\xi)\log N for group testing (in which all active users are identified, rather than just partitioned). Thus, partitioning may prove to be a more efficient approach for multi-access than group testing.Comment: This paper was submitted in June 2014 to IEEE Transactions on Information Theory, and is under review no

    Partition Information and its Transmission over Boolean Multi-Access Channels

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    In this paper, we propose a novel partition reservation system to study the partition information and its transmission over a noise-free Boolean multi-access channel. The objective of transmission is not message restoration, but to partition active users into distinct groups so that they can, subsequently, transmit their messages without collision. We first calculate (by mutual information) the amount of information needed for the partitioning without channel effects, and then propose two different coding schemes to obtain achievable transmission rates over the channel. The first one is the brute force method, where the codebook design is based on centralized source coding; the second method uses random coding where the codebook is generated randomly and optimal Bayesian decoding is employed to reconstruct the partition. Both methods shed light on the internal structure of the partition problem. A novel hypergraph formulation is proposed for the random coding scheme, which intuitively describes the information in terms of a strong coloring of a hypergraph induced by a sequence of channel operations and interactions between active users. An extended Fibonacci structure is found for a simple, but non-trivial, case with two active users. A comparison between these methods and group testing is conducted to demonstrate the uniqueness of our problem.Comment: Submitted to IEEE Transactions on Information Theory, major revisio

    Thirty Years of Machine Learning: The Road to Pareto-Optimal Wireless Networks

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    Future wireless networks have a substantial potential in terms of supporting a broad range of complex compelling applications both in military and civilian fields, where the users are able to enjoy high-rate, low-latency, low-cost and reliable information services. Achieving this ambitious goal requires new radio techniques for adaptive learning and intelligent decision making because of the complex heterogeneous nature of the network structures and wireless services. Machine learning (ML) algorithms have great success in supporting big data analytics, efficient parameter estimation and interactive decision making. Hence, in this article, we review the thirty-year history of ML by elaborating on supervised learning, unsupervised learning, reinforcement learning and deep learning. Furthermore, we investigate their employment in the compelling applications of wireless networks, including heterogeneous networks (HetNets), cognitive radios (CR), Internet of things (IoT), machine to machine networks (M2M), and so on. This article aims for assisting the readers in clarifying the motivation and methodology of the various ML algorithms, so as to invoke them for hitherto unexplored services as well as scenarios of future wireless networks.Comment: 46 pages, 22 fig

    TCM Decoding Using Neural Networks

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    This paper presents a neural decoder for trellis coded modulation (TCM) schemes. Decoding is performed with Radial Basis Function Networks and Multi-Layer Perceptrons. The neural decoder effectively implements an adaptive Viterbi algorithm for TCM which learns communication channel imperfections. The implementation and performance of the neural decoder for trellis encoded 16-QAM with amplitude imbalance are analyzed

    A selected annotated bibliography for spaceborne multiprocessing study

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    Bibliography on application of multiprocessor systems to space mission
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