论文部分内容阅读
基于中国下一代数字地面多媒体广播(DTMB-A)协议,面向广播通信领域提高数据率和支持移动性的发展趋势,该文提出一种高效频分多业务的设计方案,并给出了收发机的结构框图。其中,固定业务通过32×1 024快速Fourier变换(FFT)及256阶正交幅度调制(QAM)为固定接收用户提供高速率的高清节目;移动业务则采用偏置正交幅度调制(OQAM)和时频域内均具有良好衰减特性的各向同性正交变换算法(IOTA)作为成型滤波器,并通过最大化传输容量来确定不同移动接收环境下合适的FFT大小。仿真表明:所提方案可使移动业务对固定业务的带外干扰降低20dB,同时改善了Doppler环境下系统的接收性能,更好地满足了移动用户的需求。
Based on China’s Next Generation Digital Terrestrial Multimedia Broadcasting (DTMB-A) protocol and aiming at the trend of increasing data rate and supporting mobility in the field of broadcast communications, this paper proposes a design scheme of efficient frequency division multiple service and gives the principle of transceiver The structure of the block diagram. Among them, the fixed service provides fixed-rate high-definition high-definition programs to fixed receiving users through 32 × 1024 FFT and 256-level quadrature amplitude modulation (QAM), while the mobile services use offset quadrature amplitude modulation (OQAM) and An isotropic orthogonal transform algorithm (IOTA) with good attenuation in the time-frequency domain is used as a shaping filter and the appropriate FFT size for different mobile reception environments is determined by maximizing the transmission capacity. The simulation results show that the proposed scheme can reduce the out-of-band interference of mobile services to the fixed service by 20dB and improve the system receiving performance in Doppler environment to better meet the needs of mobile subscribers.