The Research Of Adaptive Modulation And Coding And The Realization Of Its Coding And Decoding

At first, the paper gives a brief overview to the current development of the communication and focus on the adaptive modulation and coding (AMC). In the following part, the paper presents a detail discussion and research on key technologies, including the error control coding and the wireless channel estimation and equalization. For the error control coding, we focus on the convolutional code and the Reed Solomon (RS) code. As to the convolutional code, the paper first research the code and decode algorithm of the regular convolutional code and the tail-biting convolutional code, and then proposes an improve method, which is based on the sliding window, for the decoding of the tail-biting convolutional code. While, as to the RS code, we depict the detail procedure of the coding and decoding algorithm, and then give a deep analysis to the kernel architecture of the TMS320C6747DSP, which is the realize platform of the RS code, and the kernel architecture analysis shows the great potential of the optimization. By taking full advantage of the platform’s hardware resource, we realized the optimization without changing the decode algorithm, and the decode speed is20times faster than the original decode program. Furthermore, we compared the error correct performance between the RS code and the convolutional code under the different receive symbol error rate, the result indicates the convolutional code is more suitable for the binary modulation and the RS code is more suitable for the multiple modulation.For the wireless channel estimation and equalization in the adaptive modulation and coding system, the paper first gives an overview to the fading of the wireless channel, and depicts the methods of the channel estimation. Then the paper presents a detail description of the data direct estimation (DDE) for the channel equalization, which shows the inherent good performance of DDE. At the same time, we show the great importance and the development tendency of the channel estimation. Finally, the paper takes a systematic description to the adaptive modulation and coding system, and shows the important issues, which include the establishment of modulation and coding scheme, the threshold of the modulation and coding scheme. For the establishment of the modulation and coding scheme, we combine the error control code, which is present in the previous section, and the common used modulation method, and present some coding and modulation schemes under different channel condition. As to the threshold between the modulation and coding schemes, we make detail analysis with the consideration of SNR, BER and the performance of the channel estimation. In a word, the excellent performance of the adaptive modulation and coding system comes from the harmonious and effective work of every key function.