Interference Management in LTE-based HetNets: a Practical Approach

Interference is a major obstacle in radio communications, especially when opportunistic frequency reuse is an inherent requirement for maximising spectral efficiency in heterogeneous networks. A typical example is encountered in cellular communications where macrocell-edge users receive interference from small cell transmissions that use the same radio frequency band. Innovating interference management algorithms are employed towards this end, which because of their interdependencies with numerous parameters of the target operating scenario and various low-level implementation aspects, need to be prototyped in real-time signal processing platforms in order to be credibly verified. In this paper, we present the development and experimental validation of a macrocell/femtocell coexistence scenario in close to real-life conditions. The inclusion of an agile interference management scheme increased the signal processing complexity at the physical layer. This overhead was appropriately addressed by engaging advanced parallel processing techniques, optimisations of the arithmetic operations and intelligent reuse of logic and memory resources in the field programmable gate array (FPGA)-based baseband processing architecture.