Performance Study On Turbo Non-ideal Relay Cooperation System

With the rapid development of wireless communication technology and requirements of high transfer rates, cooperative communication technology must be taken into account, fully resuing the frequency, time, space and other multi-dimensional resources to improve network coverage performance. The concept of this technology was originally proposed based on the theory of relay channels and MIMO technique. In the cooperative communication technology, the mobile station with a signal antenna can follow a certain way to share each other’s atntenna under multi-user environment, just like a virtual MIMO system.More specifically, the coded cooperation mainly through the design of channel coding to achieve cooperation, effectively reduces the transmission erroneous data and guarantees good performance. As a result, it is useful and valuable to combine cooperative communication technology and coded cooperation. Starting from this point, two diferent schemes of Turbo-based non-ideal relay cooperative system are proposed over additive gaussian white noise(AWGN)channel.The main research work of thesis including follows:1. Understanding the meaning of the Shannon limit theroy for the capacity of noisy channel and study transmission channel models and their channel capacity under point to point environment.2. Studying the encoding and decoding technology and performance of LDPC and turbo codes under point to point environment respectively.3. Performance analysis of LDPC-based non-ideal relay cooperative system and comparing it with non-cooperative system.4. Studying the performance of Turbo-based non-ideal relay cooperative system. In the resource, an interleaver is added in order to weaken the relevance between the different signals. In the relay, the parity bits are estiamted in order to reduce bit error rate because of the hard decision. Results indicate that the performance of cooperation system is better than the system without cooperation under the identical conditions.5. A turbo-based non-ideal relay with soft information cooperation system is proposed and inproved on the basis of turbo-based non-ideal relay with hard decision cooperation system. In comparison, the most significant difference is the transmission way of parity check information between relay and destination (R-D) channel. Results indicate that the performance of the former system is much better than turbo-based non-ideal realy with hard decision cooperation system under the identical conditions. Finally, the system is compared with LDPC-based non-ideal relay cooperative system and the simulation result shows that the performance of the former system is better than the later under the conditions in this paper.