| Short-wave communication places great role in wireless communication, but the poor stability of short-wave channel results in low capacity and poor reliability of the system. By using the cooperation of multiple relays to construct the virtual (Multiple Input Multiple Output, MIMO) channel, system can obtain transmission diversity and improve the reliability and channel capacity of short-wave communication system. In this paper, we study the cooperative communication system in shortwave environment, and according to the characteristics of shortwave channel, we put forward the relay selection algorithm and space-time coding scheme suitable for shortwave cooperation communication.In short-wave communication system, wireless resources such as frequency, power shortage is particularly outstanding, therefore how to reasonably and effectively use the limited power, frequency resources is a very important problem in short-wave communication. All the relays and power allocation methods are expounded in details and the subcarrier, relay and power allocation technology in short-wave communication are-investigated thoroughly. And on this basis, a joint system performance and algorithm computational complexity is proposed. The complexity of the traditional resource allocation algorithm depends on the dimension matrix when Hungary algorithm is adopted. Before using Hungary algorithm, we allocate and match sub-carrier or subcarrier grouping to reduce the dimension of the matrix, thus reducing the complexity of the calculation. Under the conditions of short-wave channel, we compare proposed resource allocation algorithm with other algorithms, the results show that the proposed resource allocation algorithm under the premise of without affecting the system performance, can effectively reduce the complexity of the system.Space-time block codes which can give full-diversity, have simple structure, and relative lower decoding complexity, thus can effectively alleviate the shortage of spectrum resources pressure. Quasi-orthogonal space-time block codes have the advantage in full rate transmission although in the expense of orthogonality. But interference is unavoidable and it may affect the system performance. To enhance the reliability of short-wave cooperative communication system, an improved quasi orthogonal space-time coding scheme with a bit feedback is proposed. After the analysis of interference terms, we design value of feedback. Under the conditions of short-wave channel, we compare the proposed space-time coding scheme with other schemes, the results show that the proposed scheme with a bit of feedback information, greatly improve the bit error performance of the system. |
