Research On The Frame With Optimal Length And LDPC Codes Technique Based On Advanced Orbiting System Protocol

Advanced Orbiting Systems (AOS) support air to ground, surface to air and air to air transmission in wireless communication, which has characteristics of large amount of data transfer, high transfer rate, time delay in the wireless communication channel and high bit error rate of channel. So how to ensure the quality of data transmission in the the wireless channel with high bit error rate to improve the throughput of link is a key issue.In this paper, the design of frame size and the technique of channel-coding is researched. The transmission scheme based on AOS combined with better error-correcting codes—LDPC codes are used to improve system throughput. The main research contents are as follows:First, this paper research the scheme using adaptive modulation and coding system combined with the algorithm based on optimal frame size. Under the different channel conditions and with different modulation and coding scheme, the optimal frame size is different in AOS system. In this paper, the algorithm of modulation and coding combined with the optimal frame size is used to improve system throughput on the basis of ensuring the reliability of communication system. On this basis, Using the scheme of Hybrid-ARQ combined with variable frame size, simulation results show: When the channel condition is bad, the system throughput performance of the joint scheme is better than the scheme using frame with fixed length in the Hybrid-ARQ.Second, analyze and compare the performance of LDPC codes. The performance of the three LDPC construction methods are compared, and several typical encoding and decoding algorithms are compared and analyzed, the better performance construction method-Extended Bit-filling algorithm is compared and analyzed on the performance of LDPC codes from code length, iterative time and different rate.At last, connected the topic needed, the program of adaptive concatenated codes with variable frame size based on AOS protocol is proposed. This scheme interlaced short LDPC codes concatenated convolutional codes combined with the technique of adaptive modulation, compared with the way of RS codes concatenated convolutional codes, the former can reduce the error rate and improve the throughput better in the communication system.