Hierarchical modulations for multimedia and multicast transmission over fading channels

In this paper, a hierarchical modulation scheme (known also as embedded, multi-resolution, or asymmetrical constellation) is studied for transmission of multicast and multimedia services over wireless fading channels. Specifically, we propose general design guidelines for multicast and multimedia transmission over fading channels with an adaptive hierarchical phase-shift-keying (PSK) constellation. Computer simulation results show that the proposed adaptive hierarchical M-PSK is more energy efficient than the traditional adaptive uniform M-PSK for both applications except some special cases. The energy gain of hierarchical PSK over uniform PSK depends only on the required quality parameters of the services in multimedia transmission. For multicasting, the gain depends on both the recipients´ link qualities and the required quality parameters of the multicast message.