为了满足语音电台抗干扰客观评估系统对语音文件对准精度的要求,在FPGA平台上设计一种基于SOPC技术的带有时间标记信息的嵌入式语音信号录取系统。在GPS接收机时间信息和秒脉冲触发下,NiosⅡ软核处理器控制音频Codec芯片WM8731对输入的音频信号进行高精度采集,将触发时间信息和采集得到的数据按照特定的格式进行打包与封装,并以FAT文件格式存储到SD卡上。由于GPS系统时间信息具有很高的时间精度,加之FPGA器件具有的时序可控特性,使得采集系统所记录的数据具有较高的绝对时间精度,完全能够满足误差小于1ms的对准精度要求。
In order to meet the requirements of the alignment accuracy of voice files in anti-interferenc, e objective evalua-tion system for voice transmitter-receiver, an embedded speech signal acquisition system with time scale intbrmation, which is based on system on a programmable chip (SOPC) technique, is designed on field programmable gate array (FPGA) platform. With the triggering of the time information of global positioning system (GPS) receiver and the pulse per second (PPS), the soft core processor Nios Ⅱ controls the audio Codec chip WM8731 for high precision collection of input audio signal, then packs and encapsulates the triggering time information and collected data in a specific format, and stores on the secure digital (SD) card in the format of file allocation table (FAT). Owing to the high time accuracy of GPS system time information and the time controllable characteristics of FPGA, data recorded by the acquisition system have higher absolute time precision, and Can completely meet the aligmnent accuracy demand that the error is less than 1 ms.