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Adaptive Network Coded Cooperation (ANCC) for Wireless Relay Networks:

Adaptive Network Coded Cooperation (ANCC) for Wireless Relay Networks: Matching Code-on-Graph with Network-on-Graph. Introduction of ANCC Background The basic idea of ANCC LDGM and LT-LDPC code for ANCC Simulation Results Performance Analysis Numerical Results Conclusion & Future Work.

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Adaptive Network Coded Cooperation (ANCC) for Wireless Relay Networks:

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  1. Adaptive Network Coded Cooperation (ANCC) for Wireless Relay Networks: Matching Code-on-Graph with Network-on-Graph Introduction of ANCC Background The basic idea of ANCC LDGM and LT-LDPC code for ANCC Simulation Results Performance Analysis Numerical Results Conclusion & Future Work

  2. 1. Introduction of ANCC Benefits of user cooperation : error rate performance, power efficiency, outage probability, throughput, transmit range Relaying strategies : Repetition, Coded Cooperation, Space-Time Coded Cooperation(STCC), Double Space-Time Coded Cooperation What if the size of existing systems are extended ?(Scalability) Those strategies may be expensive, inefficient or wasteful to operate in a large network. i.e. inefficient bandwidth, inter-user synchronization In intermediate node, network coding provides new capabilities to routing and open the possibility to achieve optimal throughput in lossless network[Ahls00][Koet03]. Since practical networking consisting of randomly faded channels are subject to link failure and topology change, fixed network codes will therefore break. ANCC, a framework that enables the real-timer adaptation of network topologies in an efficient, comprehensible, and distributed manner.

  3. 2. Background Full-Repetition Full-repetition : all the terminals repeat data Partial-Repetition Partial-repetition : each terminal repeats for only one other terminal STCC STCC : all the terminals have retrieved ANCC

  4. 3. The basic idea of ANCC

  5. 4. LDGM and LT-LDPC code for ANCC Since the bits corresponding to the identity part of H participate in only on check and therefore lack adequate protection, LDGM codes have a shortcoming of exhibiting relatively high error floors. If the orthogonal channels are time division based, then the causality condition enables the use of a better code ensemble, namely, lower-triangular low-density parity-check (LT-LDPC) codes

  6. 5. Simulation results m = 1000 transmit terminals, codeword length 2000, code rate 1/2 We observe that the performance of an LDGM ensemble is closely related to its degree D: The larger the degree, the waterfall performance but the lower the error floor.

  7. 6. Performance Analysis Outage probability and achievable rate with the mutual information Mutual information Achievable rate of a cooperative system is computed by taking the expectation on the mutual information of random channels The probability that the size of the deliver-set equals nsatifies: Outage probability is that a system fails to support a predefined information rate R at an arbitrary time

  8. 7. Numerical results Achievable rate of F-Rep decrease with the increase of terminal m. But, the achievable rate of P-Rep is not a function of m. At m=5, the achievable rate of STCC performs very close to ANCC. As increase the number of the terminals m, it slightly increase. Because the complexity and cost as dramatically increase the size of the network, The gain of STCC is not effective. ANCC is not a function of m. For large size of network, it’s very useful and powerful.

  9. 8. Conclusion and Future work • Adaptive LDGM codes and LT-LDPC codes verifies better waterfall and lower error floor. • Those codes offer a high bandwidth efficiency and a large coding gain. • ANCC for the network coding is superior to existing schemes, repetition and STCC, in the performance. • In a large size network, it is therefore practically more attractive than other coding.(lower complexity) • How we can randomly(adaptively) select relay nodes to help forward the destination using ANCC , in practically? Q

  10. 8. Future work • How we can apply the underwater acoustic communications for the performance analysis using the proposed information theoretic method about the achievable rate and outage probability based on the mutual information ?

  11. 6. Performance Analysis Repetition-based cooperation(Appendix) Outage probability and achievable rate with the mutual information Mutual information The probability that the size of the deliver-set equals nsatifies: The achievable rate of a cooperative system is computed by taking the expectation on the mutual information of random channels, with the transmission rate R

  12. Outage probability is that a system fails to support a predefined information rate R at an arbitrary time The probability that n terminals have successfully retrieved symbol i, and The conditional outage probability, Those approach will be used for the underwater acoustic communications to find and analyze the available rate and outage probability.

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