Effect of Antenna Directivity on Adaptive Modulation in an Underground Mine Gallery Effet de directivité d’antenne sur la modulation adaptative dans une galerie de mine souterraine

Adaptive modulation is an effective technique to make full use of wireless channel capacity and average spectral efficiency in multiple-input-multiple-output (MIMO) systems. Measured channel parameters performed in an underground mine environment at 2.4 GHz have been used in simulation tools based on Agilent SystemVue software. Two types of 2×2 MIMO antennas are investigated aiming to identify the optimal antenna technology that allows us to improve the performance of the MIMO channel. In addition, the modulation behavior at different locations in the undertaken mine gallery is considered. The best suitable modulation scheme is then selected depending on the obtained results [bit-error rate (BER) versus the energy per bit to noise power spectral density ratio (Eb/N0)] and with respect to the receiver location.