On The Transmission Capacities Of Overlaid Wireless Ad Hoc Networks With Multi-Antenna

The transmission capacity is recently defined to study the capacity of wire-less Ad Hoc networks, where the classic information theory is not so suitable for the decentralized wireless networks. In the field based on transmission capac-ity, the random network model provides a more practical and applicable mod-eling method for the wireless networks, while theories in stochastic geometry provides a set of powerful mathematical tools to capture the statistical charac-teristics of the random interference in the model. At the same time, the study on multi-antenna transmission under point-to-point network scenario has obtained substantial achievement. However, it still remains intractable to theoretically evaluate the performance of multi-antenna transmission for the network in pres-ence of rich interference. Under this motivation, the overlaid wireless Ad Hoc networks is concerned, which are better within the heterogeneous trend of the future networks. Our work contributes a lot to fill in the theoretical blank in the related field.The basic idea in this thesis is as follows. The random network model is applied to capture the main features of overlaid wireless Ad Hoc networks. With mathematical tools in stochastic geometry theories, the statistical charac-teristics of the random interference in the overlaid networks are obtained and finally the transmission capacity performance of multi-antenna transmission in heterogeneous network in presence of rich interference is evaluated. Based on this idea, our work starts from two fundamental spatial diversity schemes to the open loop spatial multiplexing, and ends in the optimization problem for the transmission capacity of the secondary network. In particular, the work in this thesis covers three aspects detailed as below.1. The transmission capacity performance of overlaid wireless Ad Hoc net- works with two basic multi-antenna spatial diversity schemes is investi-gated. For the first time, the closed-form expressions of the outage proba-bility for the maximum ratio combining based receive diversity and trans-mit antenna selection based transmit diversity in the overlaid wireless net-work in presence of rich interference are derived. Based on the derived expressions, the transmission capacities expressions are further obtained. Moreover, the benefits of the overlaid networks over single network are studied and the impacts of network parameters and diversity schemes on the transmission capacity are discussed.2. The transmission capacity performance of overlaid wireless Ad Hoc net-works with multi-antenna spatial multiplexing is investigated. With zero-forcing receivers to demodulate the parallel data streams, the closed-form expressions of the outage probability and the transmission capacities for the overlaid wireless Ad Hoc networks are derived. With spatial diver-sity and spatial multiplexing compared, the impacts of different network setup and multi-antenna schemes on the transmission capacity are pre-sented. Moreover, the impact of the number of data streams on the benefit of overlaid networks over single network is discussed.3. The optimization problem for the secondary network in overlaid networks with multi-antenna transmission is studied. Essential factors related to the transmission capacity of the secondary network are investigated and the optimal node density and transmit power ratio between the primary network and secondary network are also derived. On the other hand, how the value of optimal transmit power ratio will be affected is also analyzed.