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In this paper several packet combining schemes are presented for use in conjunction with the Viterbi decoder over stationary and time-varying channels. The first technique presented is an averaged diversity combiner. The averaged diversity combiner is then generalized to make use of packet weights baaed on either ideal channel state information or weights derived from side information generated by the Viterbi decoder. It is shown that the weighted diversity combiner using decoder side information performs almost as well as the system using ideal channel state information. All of the packet combining schemea discussed in this paper provide improved throughput and reliability performance relative to that provided by the standard type-I hybrid-ARQ or FEC systems. Performance bounds are derived for each of the combining schemes and their tightness verified through simulation results.In Section 4 several packet combining techniques based on the Viterbi decoder are presented and analyzed. The first system is a simple averaged diversity Combiner (ADC) in which the average soft decision value is obtained for all received copies of each bit in the received packet and the resulting combined packet decoded. The ADC provides exactly the same performance as the interleaved code cornbining system of Kallel and Haccoun [13,14] over an AWGN channel. The second system derives packet weights from side information generated by the Viterbi decoder. It is shown in Section 5 that this scheme performs almost as well as the ideal case.In Section 5 the performance bounds for the various packet cornbining schemes discussed in this paper are corroborated through the use of simulation results. In all cases it is shown that the use of packet combining substantially improves throughput performance in comparison to the type-I hybrid-ARQ protocol b decoder.

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Maximising sustainable mine closure outcomes requires a business-connected approach that takes full advantage of ongoing human and economic occupation of former mine sites. This is evidenced in the majority of successful mine closures around the world, particularly in well-populated regions. Flying in the face of this experience, current mine closure regulation, planning and implementation frequently focuses on the minutiae of environmental remediation. These two perspectives are laced with inherent tensions and contradictions that, left unresolved, will lead to suboptimal mine closure plans that will be difficult to reset when new ideas and economic options emerge. Companies, communities and regulators faced with mine closure scenarios should explicitly place future economic occupation of mine sites at the forefront of mine closure visioning and leave open future options for creative human enterprise.