Most communication systems try to maximize the signal-to-interference ratio (SINR) for better detection performance. This paper presents a new design philosophy under heterogeneous networks that makes the interference power stronger such that a receiver equipped with interference cancellation can detect and remove interference more thoroughly. As such, a better detection performance for the relatively weaker desired signal can be achieved. Equipped with mathematical derivation of the theoretical bit error rate (BER), we propose an approach that determines the most suitable power ratio between the interference and the intended signal, namely interference-to-signal ratio (ISR), leading to minimum BER. In addition, for energy efficiency we apply transmit- and receive-beamforming as well as power control to minimize the transmit power under an acceptable BER. Finally, simulation results are validated by an over-the-air field trial using software-defined radio platform under the scenario of the cell range expansion in heterogeneous networks.