Spike synchronization underlies information processing and storage in the brain. But how can neurons synchronize in a noisy network? By exploiting a high-speed (500-2,000 fps) multineuron imaging technique and a large-scale synapse mapping method, we directly compared spontaneous activity patterns and anatomical connectivity in hippocampal CA3 networks ex… (More)
Can neuronal networks produce patterns of activity with millisecond accuracy? It may seem unlikely, considering the probabilistic nature of synaptic transmission. However, some theories of brain function predict that such precision is feasible and can emerge from the non-linearity of the action potential generation in circuits of connected neurons. Several… (More)
The brain is self-writable; as the brain voluntarily adapts itself to a changing environment, the neural circuitry rearranges its functional connectivity by referring to its own activity. How the internal activity modifies synaptic weights is largely unknown, however. Here we report that spontaneous activity causes complex reorganization of synaptic… (More)
Recent low-density parity-check (LDPC) codes have shown capacity-approaching performance for various communications systems. However, their promising performance cannot always be obtained due to practical constraints such as finite codeword length, finite iteration, finite memory, and finite precision. In this paper, we focus on a practical design method of… (More)
We propose to use Han-Kobayashi (HK) coding and dirty-paper coding (DPC) to cope with inter-carrier interference (ICI) in dual-carrier transmissions. We show the considerable benefit of those methods to increase throughput in presence of strong ICI for dense carrier spacing. This work may not be copied or reproduced in whole or in part for any commercial… (More)
Superchannel transmission is a candidate to realize Tb/s-class high-speed optical communications. In order to achieve higher spectrum efficiency, the channel spacing shall be as narrow as possible. However, densely allocated channels can cause nonnegligible inter-channel interference (ICI) especially when the channel spacing is close to or below the Nyquist… (More)
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We show a great potential of nonbinary (NB) LDPC convolutional codes in low-latency decoding for HDM. We show that NB-LDPC can provide considerable performance improvement compared to conventional BICM-ID, which requires soft-decision feedback. This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in… (More)