Study Of Channel Coding In Wireless Mobile Channel

As an important part of new information technology, the internet of things (IOT) will be rapidly development.the key technology of IOT including RFID, sensor networks and detection and so on. All of these technologies to come true needs the study of short range wireless communication in IOT. It’s different from traditional wireless communication, on the first place, transponders of IOT are mainly passive and semi-passive, therefore, the transponder arithmetic capacity and computing power are subject to greater restrictions; on the second place, the mobility between transponders and readers are weak relatively,so errors are fewer, the important point is how to solve errors use less power; the third difference is that reader always communicate with transponders in broadcast mode, so there are many transponders reply in same time, and it cause serious multi-user interference, how to use low power and less operation to solve the problem is the point. This paper solves the above problems.Base on the study of channel coding and IOT system characteristics, this paper formulate a method called channel coding and multiple user detection method in IOT. There are two point of the method, on the channel coding part, it use low-density parity-check (LDPC) codes, it can decode better in low SNR, In order to further saves power, the certain message encoded before it written in the transponders on the up-link; on the down-link, it use cyclic code to check error. On the multi user issue, it use small grouping multiple user detection, it separate transponders into different groups, different groups communication in different time, transponders in same groups use orthogonal code to separate. Both of the two sections are easy to achieve.The method mentioned in this paper can decrease mistake, Solve multi-user interference problems with low power. It’s better than prevent collision algorithm when transponders reaches a certain number. At last in this paper, the method is been used in logistics field, it can increase of efficiency and guarantee precision rate, it’s useful for IOT application.