Energy Efficiency of Hybrid Cellular With Heterogeneous QoS Provisions

In this letter, we consider a hybrid broadcast and unicast cellular network (hybrid cellular for short) with heterogeneous quality of service (QoS) constraints in the low-power regime. In particular, we consider the unicast user with delay constraint and the broadcast user with outage constraint. The transmission energy efficiency of the dirty paper coding (DPC) and time division multiple access (TDMA) schemes are analyzed and compared from information theoretic point of view. Specifically, the minimum energy per bit and the wideband slope region are derived in closed forms. While both DPC and TDMA schemes require the same minimum energy per bit, DPC outperforms TDMA with regard to the wideband slope region. We also obtain the critical points for both schemes beyond which the wideband slope decreases for both unicast and broadcast users. Finally, we show how the heterogeneous QoS constraints affect the energy efficiency in hybrid cellular.