Abstract: With the characteristics of the simple system architecture，low cost and small power consuming，Time Hopping Impulse Radio（TH-IR） Ultra Wideband（UWB） technology becomes popular in recent years.This paper proposes a TH-IR based Rate-Adaptive Time Hopping（RATH） Medium Access Control（MAC） protocol with a guarantee of bit error rate and transmission rate provision.The RATH protocol allocates time hopping code to multiple users for channel access.According to the Signal to Interference and Noise Ratio（SINR） of receiver，RATH determines establishment of each link，which has a variable transmission rate adjusted by the Rate-Adaptive algorithm.Simulation experiments via NS2 show that RATH is able to significantly enhance the performance of the network in terms of effective throughputs and transmission delay，with respect to the fixed rate MAC protocols such as U-MAC.

摘要： 在超宽带（UWB）通信中，跳时冲激无线电（TH-IR）技术具有系统结构简单、成本低、功率小等优点，得到广泛的研究及应用探索。基于TH-IR UWB技术，提出了一种能够保证链路误码率及传输速率的自适应速率跳时（Rate-Adaptive Time Hopping，RATH）介质访问控制（MAC）协议，该协议利用跳时码管理多用户的信道访问，依据接收节点的信干比控制链路的建立，并采用自适应速率算法调节链路的传输速率。NS2平台下的仿真实验表明，与U-MAC等已有的固定速率协议相比较，RATH MAC协议能够使网络有效吞吐量和传输时延得到明显改善。