In this paper, we consider the overlaid system of single frequency network broadcast service and cellular-based unicast data service. In general, broadcast service and unicast data service were considered as a separate services so that different frequency resources have been allocated for each. As the frequency resource get more expensive, however, there were some efforts to provide both the broadcast and unicast service over the same frequency resource by employing the so-called superposition coding. In fact, such an service overlay system has already been accepted as a standards in 3GPP long-term evolution (LTE). In this paper, we specifically investigate such overlay system within 3GPP framework and evaluate their performance in terms of BC coverage and UC data throughput.