Rate compatible punctured turbo code for LMDS systems

LMDS system is a two-way digital cellular system operating at 20–50 GHz. It offers the services of the audio, video, multimedia and data transmission, so LMDS can meet all kinds of users’ demands. However, rain attenuation and inter cell interference (ICI) influence the factor of Quality of Service (QoS) in LMDS system. In order to combat the impacts of rain fade and of inter cell interference on LMDS systems, we propose a new criterion for the choice of the puncturing patterns, leading systematic rate-compatible codes with respect to the rain attenuation to improve the performance of LMDS systems. In accordance with the system situation, a parameter with regard to rain attenuation will be used to adjust the code rate to reduce the redundancy bit and to improve the bandwidth efficiency. Simulation results show that the proposed rate compatible punctured Turbo Code for LMDS systems compared with the one without punctured Turbo Code scheme lead to an improvement of bandwidth efficiency. Moreover, the BER of two schemes are very close.