On the performance of LDPC and turbo decoder architectures with unreliable memories

In this paper, we investigate the impact of faulty memory bit-cells on the performance of LDPC and Turbo channel decoders based on realistic memory failure models. Our study investigates the inherent error resilience of such codes to potential memory faults affecting the decoding process. We develop two mitigation mechanisms that reduce the impact of memory faults rather than correcting every single error. We show how protection of only few bit-cells is sufficient to deal with high defect rates. In addition, we show how the use of repair-iterations specifically helps mitigating the impact of faults that occur inside the decoder itself.

Bernard Mandeville and the doctrine of laissez-faire

The view of Mandeville as a pioneer of laissez-faire is difficultto reconcile with his repeated insistence that private vices were turnedinto public benefits by the ‘dexterous management of the skilfulpolitician’. Even if references to the skilful politician are regarded asshorthand for a legal and institutional framework, there remains thequestion of whether such a framework is a spontaneous order or theproduct of purposeful experiment as Mandeville thought? Mandevillewarned about the harmful effects of meddling but his complaint wasabout the actions of fashionable do-gooders rather than government. Heunderstood that the voluntariness of a transaction could be regarded asa defence against complaints of unfairness but he was quick to pointout the limitations of voluntariness especially in the market for labour.Mandeville’s objective was to teach people what they are not what theyshould be. He pointed to the strengths of the emerging market systembut was not afraid to expose its faults.