Achievable Rates and Power Loading in MIMO-THP Systems

MIMO-THP System with Imperfect CSI

“…Also, the upper bound can be obtained essentially by neglecting the spatial interference term k w in (16) [17]. The lower bound depends largely on the variance of k w [15].…”

“…The lower bound depends largely on the variance of k w [15]. A lower bound on achievable rate can be found as [17]:…”

“…Calculation of the above mutual information seems to be difficult and we try to find an upper and lower bound of (16) by some approximations. Remark 1: An upper bound on the achievable rate of the channel produced by MMSE-THP of (16) can be found as [17]:…”

“…(so that symbol ⊥ stand for statistical independence) the received vector r can be decoupled in K parallel streams as 1 [17]:…”

“…The upper bound attained in (17) can be simplified if some approximations are allowed so that a quasi-optimal (or sub-optimal) closed form solution can be found. This approximations can be done based on the value of σ / t (See [17]).…”