在低负载时断开网络拓扑部分链路是IP over WDM光网络中一种有效的节能方法,但链路断开时段的选择对IP over WDM光网络的阻塞率和节能效果有较大的影响,对此,根据网络中IP流量一天中的周期性变化规律,设计了一种链路能效分时控制策略调整非峰值时间段网络拓扑连接关系,并建立整数线性规划能耗模型,设计了便于求解模型的启发式算法.仿真结果表明,与无链路断开的原始策略相比,所提策略能有效降低网络能耗;与现有的链路断开策略相比,新策略能获得更低的网络请求阻塞率.
A novel construction method of quasi-cyclic low-density parity-check(QC-LDPC) code is proposed based on the finite field multiplicative group,which has easier construction,more flexible code-length code-rate adjustment and lower encoding/decoding complexity.Moreover,a regular QC-LDPC(5334,4962) code is constructed.The simulation results show that the constructed QC-LDPC(5334,4962) code can gain better error correction performance under the condition of the additive white Gaussian noise(AWGN) channel with iterative decoding sum-product algorithm(SPA).At the bit error rate(BER) of 10-6,the net coding gain(NCG) of the constructed QC-LDPC(5334,4962) code is 1.8 dB,0.9 dB and 0.2 dB more than that of the classic RS(255,239) code in ITU-T G.975,the LDPC(32640,30592) code in ITU-T G.975.1 and the SCG-LDPC(3969,3720) code constructed by the random method,respectively.So it is more suitable for optical communication systems.
