Due to the limited space in the tunnel environment, multiple-input multiple-output (MIMO) systems with double-port fed leaky coaxial cables (LCXs) can not only reduce the number of LCXs, but also improve the channel capacity. Based on the geometry based on single bonce (GBSB) and electromagnetic field radiation theory of LCX, a MIMO channel model with double-port fed LCX in a tunnel scenario is proposed in this paper. The channel impulse response (CIR) is derived, and verified with measurement results in terms of channel capacity. The distribution of channel capacity of single double-port fed LCX under different LCX lengths in the tunnel scenarios has also been analyzed in this work, and the distribution of channel capacity for the LCX-MIMO system with long LCX is predicted. The results show that the single double-port fed LCX-MIMO system outperforms the dipole antenna MIMO system with respect to channel capacity in the considered tunnel scenarios.
Keywords: capacity; channel model; leaky coaxial cable (LCX); multiple–input multiple–output (MIMO); tunnel.