ABSTRACT
Diversity gain represents how much the transmission power can be reduced when a diversity scheme is introduced, without a performance loss. Spatial Multiplexing Gain (SMG) refers to the capacity of a system in transmitting different streams of data from the same resource in separate spatial dimensions. Diversity and multiplexing tradeoff describes the relation between diversity gain and multiplexing gain, which is an important performance measure for Multiple-Input Multiple-Output (MIMO) or cooperative communication system (Dohler & Li, 2010). DMT can be derived from outage probability (Dohler & Li, 2010, Zheng & Tse, 2003). Considering the instantaneous sum-rate of two-opposite traffic flows, Louie and Vucetic (2009) presented the expression of outage probability for the TDBC protocol. That sumrate measure is rather useful to investigate the whole capacity of the system. Nevertheless, in a multiuser system, the whole system is in outage when any user in the system is outage (Tse et al, 2004, Tse, 2005, Yi et al, 2011). Considering that, Yi et al. (2011) and Wang and Tao (2012) respectively studied the expression of the outage probability for the MABC protocol and the TDBC protocol. Their work inspired us to analyze DMT expression of the TDBC protocol. But it is difficult to analyze DMT curve of the TDBC protocol from the complicated expression of the outage probability given by Wang and Tao (2012), especially in finite-SNR region. Therefore, Wang and Tao discussed only the DMT performance of the TDBC protocol when the signal-to-noise ratio (SNR) goes to infinite.
