Kosuke Ishibashi

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We propose a new online learning algorithm which provably approximates maximum margin classifiers with bias, where the margin is defined in terms of p-norm distance. Although learning of linear clas-sifiers with bias can be reduced to learning of those without bias, the known reduction might lose the margin and slow down the convergence of online learning(More)
We consider online learning of linear classifiers which approximately maximize the 2-norm margin. Given a linearly separable sequence of instances, typical online learning algorithms such as Perceptron and its variants, map them into an augmented space with an extra dimension, so that those instances are separated by a linear classifier without a constant(More)
The use of the spatial diversity is known to greatly improve the performance over the quasi-static wireless channel. In this paper, we propose a new coded cooperation protocol based on rate-compatible turbo codes. We consider the communication scenario to take place between clusters of nearby nodes with single antenna and demonstrate by a simple example(More)
Recently, multihop wireless networks have gained much attraction. Since the available bandwidth and battery are strictly limited, multihop wireless networks should communicate efficiently. If the error correcting code is used, by using the longer codeword, the decoding error probability can be improved. Therefore, in this paper, we propose the information(More)
This paper proposes a new coded cooperation protocol based on multilevel coded modulation for the case when the number of cooperative nodes is arbitrary. If the number of cooperative nodes is N, the proposed system makes a cooperative diversity with the multilevel coded 2<sup>N</sup>-PAM. Multilevel coded 2<sup>N</sup>-PAM can be decomposed into N parallel(More)
We propose a new scheme for collaborative (or cooperative) communications using bit-Interleaved coded differential PSK with cyclic delay diversity in orthogonal frequency-division multiplexing (OFDM). bit-interleaved coded DPSK with cyclic delay diversity in OFDM can cope with the increased frequency selectivity, and enable picking up the spatial diversity(More)
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