An adaptive data transmission scheme based on variable spreading gain (VSG) is studied in cellular CDMA network in presence of soft handoff (HO). The processing gain is varied according to traffic intensity meet-ing a...An adaptive data transmission scheme based on variable spreading gain (VSG) is studied in cellular CDMA network in presence of soft handoff (HO). The processing gain is varied according to traffic intensity meet-ing a requirement on data bit error rate (BER). The overall performance improvement due to processing gain adaptation and soft HO is evaluated and compared with a fixed rate system. The influence of soft HO pa-rameters on rate adaptation and throughput and delay performance of data is indicated. Further truncated automatic repeat request (T-ARQ) is used in link layer to improve the performance of delay sensitive ser-vices. The joint impact of VSG based transmission in presence of soft handoff at physical layer and T-ARQ at link layer is evaluated. A variable packet size scheme is also studied to meet a constraint on packet loss.展开更多
A device-to-device （D2D） communication mode underlaying cellular network in a single- cell environment is introduced. A practical method based on link adaptation with automatic repeat request （ARQ） is presented. L...A device-to-device （D2D） communication mode underlaying cellular network in a single- cell environment is introduced. A practical method based on link adaptation with automatic repeat request （ARQ） is presented. Link adaptation technique, which combines adaptive modulation and coding （ AMC ） with truncated ARQ, can maximize the cellular UEs＇ data rate under prescribed delay and performance constraints. The proposed method can maximize the total transmission rate when an outage probability is determined. Numerical results show that with proper power control, the in- terference between the two links can be coordinated to increase the sum rate without overwhelming the cellular service.展开更多
针对联合自适应调制编码(adaptive modulation and coding,AMC),自动重传请求(automatic repeatrequest,ARQ)与包分割传输3种机制的通信系统,提出了一种ARQ多帧动态周期反馈机制,并建立了分析此系统的马尔可夫链模型,得到了包平均时延...针对联合自适应调制编码(adaptive modulation and coding,AMC),自动重传请求(automatic repeatrequest,ARQ)与包分割传输3种机制的通信系统,提出了一种ARQ多帧动态周期反馈机制,并建立了分析此系统的马尔可夫链模型,得到了包平均时延、平均反馈次数、平均掉包率和系统吞吐量等多种性能指标。在此基础上提出了在服务质量(quality of service,QoS)条件约束下,以最大化系统有效吞吐量为目标的双向链路跨层最优化算法。仿真结果表明,提出的马尔可夫链模型能精确预测系统的性能,与现有的单帧反馈和多帧固定周期反馈相比,提出反馈机制可达到更大的系统有效吞吐量。展开更多
文摘An adaptive data transmission scheme based on variable spreading gain (VSG) is studied in cellular CDMA network in presence of soft handoff (HO). The processing gain is varied according to traffic intensity meet-ing a requirement on data bit error rate (BER). The overall performance improvement due to processing gain adaptation and soft HO is evaluated and compared with a fixed rate system. The influence of soft HO pa-rameters on rate adaptation and throughput and delay performance of data is indicated. Further truncated automatic repeat request (T-ARQ) is used in link layer to improve the performance of delay sensitive ser-vices. The joint impact of VSG based transmission in presence of soft handoff at physical layer and T-ARQ at link layer is evaluated. A variable packet size scheme is also studied to meet a constraint on packet loss.
基金Supported by the China Major National S&T Program(2010ZX03003-003)China-EU International Scientific and Technological Cooperation Program(0902)+1 种基金the Sino-Swedish IMT-Advanced and Beyond Cooperative Program(2008DFA11780)the Open Project Program of Guangdong Provincial Key Laboratory of Short-Range Wireless Detection and Communication and PCSIRT-IRT(1005)
文摘A device-to-device （D2D） communication mode underlaying cellular network in a single- cell environment is introduced. A practical method based on link adaptation with automatic repeat request （ARQ） is presented. Link adaptation technique, which combines adaptive modulation and coding （ AMC ） with truncated ARQ, can maximize the cellular UEs＇ data rate under prescribed delay and performance constraints. The proposed method can maximize the total transmission rate when an outage probability is determined. Numerical results show that with proper power control, the in- terference between the two links can be coordinated to increase the sum rate without overwhelming the cellular service.
文摘针对联合自适应调制编码(adaptive modulation and coding,AMC),自动重传请求(automatic repeatrequest,ARQ)与包分割传输3种机制的通信系统,提出了一种ARQ多帧动态周期反馈机制,并建立了分析此系统的马尔可夫链模型,得到了包平均时延、平均反馈次数、平均掉包率和系统吞吐量等多种性能指标。在此基础上提出了在服务质量(quality of service,QoS)条件约束下,以最大化系统有效吞吐量为目标的双向链路跨层最优化算法。仿真结果表明,提出的马尔可夫链模型能精确预测系统的性能,与现有的单帧反馈和多帧固定周期反馈相比,提出反馈机制可达到更大的系统有效吞吐量。
