To analyze the performance of cluster computing systems with identical computing power but different failure distribution, a k-to- l-out-of- n structure was used to model system performance, and a new analytical method based on Binary Decision Diagram (BDD) was proposed for the performance analysis. A new and efficient BDD algorithm that makes full use of the special k-to- l-out-of- n structure was also proposed using a top-down manner, which solved the problem that the traditional bottom-up generation algorithm must generate a large number of intermediate redundant nodes. Then the proposed BDD was used to efficiently calculate the probability of the system being at a specific performance level. At last, some examples were provided to illustrate the proposed BDD-based performance analysis methodology as well as its efficiency in analyzing large-scale cluster computing systems.

To overcome the severe performance loss of conventional coded cooperation schemes under dynamic channel conditions in mobility scenarios, a novel adaptive coded cooperation scheme was proposed by using rate-compatible Low-Density Parity Check (LDPC) codes in combination with a Hybrid Automatic Repeat reQuest (HARQ) protocol. It was assumed that channel state information changed during each transmission. By automatic retransmission of unequal length incremental redundancy, the equivalent code rates at the cooperative and destination nodes could be nonlinearly adjusted with channel conditions. The expressions for outage probability and throughput were derived for evaluating the system performance of the proposed scheme, and theoretical analysis and simulation results were presented. These results show that, compared with conventional schemes and equal-length retransmission schemes, the proposed scheme with properly designed compatible rates can effectively reduce the system outage probability, increase the throughput, and improve the transmission reliability of cooperative communications in mobility scenarios.