A RPC-based Slotted Aloha Multiple Access Technology

Multiple access RPC(Random Projection Code)technology can simultaneously decode multiple users of the signal,so when applied to multi-access communication system,the communication system needn't make signal orthogonal like TDMA,FDMA and CDMA,improving the signal transmission efficiency.This paper combines it with time slot Aloha protocol,proposing an RPC-based Slotted Aloha Multiple access technology.First of all,this paper introduces the basic principles of RPC,describes the RPC multi-access technology and analyses its performance.Then we introduce the Slotted Aloha protocol and combine it with the RPC multiple access technology and propose the RPC-based Slotted Aloha multiple access technology.We use each user's slot access probability control the number of users transmitting signal together,and owing to the RPC multiple access technology,improving the transmission efficiency.By selecting the proper access probability of each user we can get the best transmission efficiency.Simulation shows that when the average users in the load is 1,the technology makes the successful transmission probability of the user be 2.3 times of the S-Aloha protocol.Finally,this paper uses incremental iterative decoding to reduce the decoding complexity,but to realize it,we have to store a large number of soft information.The paper use quantization to decrease it while promise the performance of the system.The simulation results show that the decoding complexity between incremental iteration method and the old method is 1 10,and the number of soft information we store after quantization is much smaller than the method of not quantization,the ratio of it is 1 1024,when the number of the information bit is 4096 and the SNR is 13 dB.The technology proposed in this paper improves the efficiency of signal transmission by increasing the probability of successful transmission of the signal each time the user transmits the signal.The incremental iterative decoding and the optimization method based on it make the technology based proposed in this paper easier to be applied in the actual communication system.