Enhancing Macrocell Downlink Performance through Femtocell User Cooperation

This paper studies cooperative techniques that rely on femtocell user diversity to improve the downlink communication quality of macrocell users. We analytically analyze and evaluate the achievable performance of these techniques in the downlink of Rayleigh fading channels. We provide an approximation of both the bit-error rate (BER) and the data throughput that macrocell users receive with and without femtocell user cooperation. Using simulations, we show that under reasonable SNR values, cooperative schemes improve both the BER and the data throughput of macrocell users significantly when compared with the traditional, noncooperative scheme.