The Design Of The Notebook With A Built-in Cmmb Receiving System

CMMB(China Mobile Multimedia Broadcasting)is officially identified as the mobile digital TV standards by the State Administration of Radio Film and Television. It is a domestic self-developed mobile digital TV standard for mobile phone, PND, Mp4, notebook and other mobile terminal systems. For the Three-Network Convergence required, this paper provides a regular laptop built-in CMMB receiver system solution.This solution contains the hardware and software design, the CMMB receiver card will be designed to the PCI Express Mini card. CMMB bit rate is very low, so we select the USB bus as the system interface. We choose Somagic SMI2020as the USB controller. SMI2020has a special design for DTV, and provide the BDA driver. It is very convenient for our development.We have chosen Maxscend MXD0251CMMB demodulator chip. It meets the CMMB receiver performance indicators, and also provides good price. CMMB video signal is transmitted to SMI2020by the MPEG-TS interface from MXD0251, SMI2020CMMB video signal decryption, and then through the USB bus to the PC, the PC player to decode and play the CMMB.Another challenge is the embedded antenna for notebook built-in CMMB applications, this paper will introduce the different embedded antenna technology. We have chosen Ethertronics embedded antenna, this antenna is a electrically tunable antenna. Although the integration is more complicated, but it can provide better performance received.We tested according to CMMB specification, Including product functional testing, closed-loop performance testing and the open-loop performance test. The test results show that the laptop built-in CMMB receiver system to meet the design requirements. Embedded antenna reception to meet the requirements, it can receive CMMB programs smoothly. This solution provides a reference for the promotion of notebook built-in CMMB system.