专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明公开

EP1021876A4 SIGNAL PROCESSING METHOD AND DEVICE 审中-公开
标题翻译：信号处理方法和装置
公开(公告)号：EP1021876A4
公开(公告)日：2003-05-02
申请号：EP98942269
申请日：1998-08-26
申请人： ATMEL CORP
发明人： LIPASTI LAURI , KOVANEN ARHIPPA
IPC分类号： H03M3/02 , H03M7/00 , H03M7/36 , H04B14/06
CPC分类号： H03M3/458 , H03M7/3028 , H03M7/304
摘要： The invention relates to digital signal processing and specificly to level control of a pulse density modulated (PDM) signal generated by a sigma-delta modulator. A single-bit pulse density modulated PDM signal is generated by a first sigma-delta modulator (2) being an analog modulator, for instance. Level control is performed by multiplying the single-bit pulse density modulated PDM signal by a multibit multiplier (300) to obtain a multibit number stream, which is reconverted into a single-bit PDM signal by a second digital sigma-delta modulator (4). In accordance with the invention, the performance of the second sigma-delta modulator (4) is better than that of the first sigma-delta modulator (2), as to the signal-to-noise ratio. Thus, the most significant factor in the total signal-to-noise ratio (SNR) is the noise level of the first sigma-delta modulator (2), by which the PDM signal was originally generated. In the subsequent second sigma-delta modulator (4), the PDM signal can then be attenuated as much as is the difference between the SNR performances of the modulators without any decrease in the total signal-to-noise ratio. A relative amplification of the PDM signal is provided in this manner.

IPRDB

热门服务

关于我们

友情链接

联系方式