Theoretical Analysis of the Co-Existence of LTE-A Signals and Design of an ML-SIC Receiver

The increasing number of mobile devices and the demand for large throughput requiring applications has hampered access to the limited frequency spectrum. The goal of this work is to introduce a new degree of freedom to the reuse of occupied resources by intentionally creating co-existence between different types of signals. First, the co-existence of orthogonal frequency division multiple access and single carrier-frequency division multiple access signals is introduced and analyzed for a conventional successive interference cancellation (c-SIC) processing. Then, the average bit-error-rate is derived for the proposed co-existence approach as a baseline. The results of the analysis lead to the design of an improved adaptive multi-user detection (MUD) approach, which outperforms the c-SIC receiver. The proposed MUD approach performs iterative likelihood testing and a signal-to-interference plus noise ratio based processing to improve the decoding performance. Additionally, three different power control schemes are proposed for heterogeneous networks to improve the gain further and observe the performance in the system-level. Our results show that the proposed combination of methods works well in dense mobile communication environments.