Design And Simulation Of A New ARQ Protocol In 4th Generation Of Communication System

Today mobile communication systems are designed as logically separate networks. They are primarily designed to provide cost efficient wide area coverage for a rather limited number of users with moderate bandwidth demands (voice + low rate data). The consumer of telecommunication services of tomorrow will expect to receive the same services in a wireless fashion as he receives from a fixed network. Third generation mobile systems, such as UMTS and IMT-2000, aim at only partially solving these problems. By mainly extending second generation technologies higher data-rates, up to 2 Mbit/s are offered but only to a limited number of users at the time and only in certain areas. In order to enable the use of truly new and innovative multimedia services, 4G communication systems are designed. In 4G communication system, Automatic Repeat reQuest(ARQ) technology is necessary to support multiple mobile terminal to communicating in shared wireless channel. In current mobile communication, there is not much high requirement for the efficiency of utilization of wireless resource because of absence of applications, however, in high speed wireless mobile IP communication system, transmission rate has been enhanced greatly and applications with burst character would be in the leading position. So, one of the key technologies is multiple access control for highly efficient utilization of limited network resource. From the view of development of ARQ technology, current ARQ technologies had resolved the problems of data transmission in wire network, but there is not an ideal corresponding way in wireless network. The main hard point lies in the high transmission delay and high bit error ratio. This paper introduces the main ARQ technologies in wireless channel, discusses the key points of designing ARQ protocols and suggests an ARQ protocol for the new generation cellular mobile communication system. At last, a simulation platform is established to verify the protocol. The simulation results validate that this new protocol could adapt itself to the high transmission delay and high bit error ratio.