| Popis: |
To efficiently accommodate the terrestrial broadcasting service and the mobile service within the same spectrum over Chinese Digital Television Terrestrial Multimedia Broadcasting (DTMB) system, a novel multi-service datacasting scheme in a backward compatible manner is proposed in this paper. In this scheme, an equivalent QAM (E-QAM) mapping method is adopted for mobile services. Moreover, to reduce the impact of the larger peak to average power ratio (PAPR)caused by the E-QAM, a random constellation extension (RCE)technique is further proposed. Both theoretical analysis and computer simulation show that this scheme not only supports the normal reception of the traditional terrestrial broadcasting service in DTMB receivers, but also provides better mobile reception performance at acceptable spectral efficiency penalty. |
