The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained pop...The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained popularity after the application of the Fast Fourier Transform (FFT) and its inverse (IFFT) to modulate the signal in many subcarriers. This paper discusses implementation aspects of an OFDM system;such system is characterized by considering real constraints, including the memory consumption and the processing time. The OFDM modulator, channel samples and OFDM demodulator were implemented entirely in the DSP TMS320C6678 platform. As a proof-of-concept, a 256-QAM OFDM BER performance is compared with theoretical values. Moreover, the memory size is not demanding, consuming very few resources. It was observed a very high number of DSP clock cycles needed for the OFDM signal modulation, corresponding to more than 4 times the number used in demodulating the signal.展开更多
随着军用无人机等航电系统不断朝着小型化、智能化、综合化的方向发展,如何有效满足装备的低SWaP(Size,Weight and Power)要求成为一大难题。介绍了某型宽带综合化数字预处理模块的研制,利用“裸芯片+高密度基板”系统级封装(SiP)的方...随着军用无人机等航电系统不断朝着小型化、智能化、综合化的方向发展,如何有效满足装备的低SWaP(Size,Weight and Power)要求成为一大难题。介绍了某型宽带综合化数字预处理模块的研制,利用“裸芯片+高密度基板”系统级封装(SiP)的方式对信号处理平台(DSP、FPGA、SerDes和DDR芯片)进行集成,替代目前业界普遍采用的“封装芯片+印制板+平面集成”的传统方式,实现宽带综合化数字信号处理模块的高密度集成。在主要性能指标(可编程逻辑资源、定点处理能力、浮点处理能力、数据传输速率)不变的情况下,使得信号处理模块的面积降低为45 mm×45 mm,重量降低到103 g。展开更多
文摘The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained popularity after the application of the Fast Fourier Transform (FFT) and its inverse (IFFT) to modulate the signal in many subcarriers. This paper discusses implementation aspects of an OFDM system;such system is characterized by considering real constraints, including the memory consumption and the processing time. The OFDM modulator, channel samples and OFDM demodulator were implemented entirely in the DSP TMS320C6678 platform. As a proof-of-concept, a 256-QAM OFDM BER performance is compared with theoretical values. Moreover, the memory size is not demanding, consuming very few resources. It was observed a very high number of DSP clock cycles needed for the OFDM signal modulation, corresponding to more than 4 times the number used in demodulating the signal.