A New Random Access Method for Satellite-UMTS

A new random access method is submitted in this paper, which can be used in Satellite-UMTS system and others characterized long transmission delay. With reference to the access design in S-UMTS, the method designs some new configurations for access frame and slot, and proposes a new way to transmit the access request. With the enlargement of spreading ratio for access message, the bit error ratio of message is reduced. The detection probability of access preamble is enhanced because of augmentation for its length and increased length of preamble code, which can reduce the collision probability. The enlargement of protected interval time can cope with the difference of transmission delay between user equipment (UE) under the same beam-spot. The proposal transmission procedure can improve average accepted time in evidence. In addition, Maximum-Like algorithm is suggested to detect the preamble code of UE and reduce times of compute.