attracted much interest recently (see e.g., [@wu-downlink]–[@deli] and references therein). For instance, Tang and Zhang in [@tang-powerrate] considered the effective capacity when both the receiver and transmitter know the instantaneous channel gains, and derived the optimal power and rate adaptation technique that maximizes the system throughput under QoS constraints. These results are extended to multichannel communication systems in [@tang-multichannel]. Liu *et al.* in [@finite] considered fixed-rate transmission schemes and analyzed the effective capacity and related resource requirements for Markov wireless channel models. In this work, the continuous-time Gilbert-Elliott channel with ON and OFF states is adopted as the channel model while assuming the fading coefficients as zero-mean Gaussian distributed. A study of cooperative networks operating under QoS constraints is provided in [@liu-cooperation]. In [@deli], we have investigated the energy efficiency under QoS constraints by analyzing the normalized effective capacity (or equivalently the spectral efficiency) in the low-power and wideband regimes. We considered variable-rate/variable-power and variable-rate/fixed-power transmission schemes assuming the availability of channel side information at both the transmitter and receiver or only at the receiver.

In this paper, we consider a wireless communication scenario in which only the receiver has the channel side information, and the transmitter, not knowing the 