Bits Through Deterministic Relay Cascades with Half-Duplex Constraint
| Autor: | Christoph Hausl, Tobias Lutz, Ralf Kötter |
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| Rok vydání: | 2011 |
| Předmět: |
FOS: Computer and information sciences
Computer science Computer Science - Information Theory Information Theory (cs.IT) 05 social sciences ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS 050801 communication & media studies 020206 networking & telecommunications 02 engineering and technology Data_CODINGANDINFORMATIONTHEORY Library and Information Sciences Topology Synchronization Computer Science Applications law.invention ddc 0508 media and communications Relay law Linear network coding 0202 electrical engineering electronic engineering information engineering Information Systems Computer Science::Information Theory |
| Popis: | Consider a relay cascade, i.e. a network where a source node, a sink node and a certain number of intermediate source/relay nodes are arranged on a line and where adjacent node pairs are connected by error-free (q+1)-ary pipes. Suppose the source and a subset of the relays wish to communicate independent information to the sink under the condition that each relay in the cascade is half-duplex constrained. A coding scheme is developed which transfers information by an information-dependent allocation of the transmission and reception slots of the relays. The coding scheme requires synchronization on the symbol level through a shared clock. The coding strategy achieves capacity for a single source. Numerical values for the capacity of cascades of various lengths are provided, and the capacities are significantly higher than the rates which are achievable with a predetermined time-sharing approach. If the cascade includes a source and a certain number of relays with their own information, the strategy achieves the cut-set bound when the rates of the relay sources fall below certain thresholds. For cascades composed of an infinite number of half-duplex constrained relays and a single source, we derive an explicit capacity expression. Remarkably, the capacity in bits/use for q=1 is equal to the logarithm of the golden ratio, and the capacity for q=2 is 1 bit/use. Comment: accepted for publication in IEEE Transactions on Information Theory |
| Databáze: | OpenAIRE |
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