>In order to reconstruct that sinusoid, you'll need a filter with >an infinitely steep transition band.
No, even an ideal reconstruction filter won't do it. You've got your +Nyquist component sitting right on top of your -Nyquist component. Hence the aliasing. The information has been lost in the sampling, there's no way to reconstruct without some additional side information. E On Tue, Aug 18, 2015 at 1:45 PM, Tom Duffy <tdu...@tascam.com> wrote: > In order to reconstruct that sinusoid, you'll need a filter with > an infinitely steep transition band. > You've demonstrated that SR/2 aliases to 0Hz, i.e. DC. > That digital stream of samples is not reconstructable. > > On 8/18/2015 1:28 PM, Peter S wrote: > > That's false. 1, -1, 1, -1, 1, -1 ... is a proper bandlimited signal, >> and contains no aliasing. That's the maximal allowed frequency without >> any aliasing. It is a bandlimited Nyquist frequency square wave (which >> is equivalent to a Nyquist frequency sine wave). From that, you can >> reconstruct a perfect alias-free sinusoid of frequency SR/2. >> > > NOTICE: This electronic mail message and its contents, including any > attachments hereto (collectively, "this e-mail"), is hereby designated as > "confidential and proprietary." This e-mail may be viewed and used only by > the person to whom it has been sent and his/her employer solely for the > express purpose for which it has been disclosed and only in accordance with > any confidentiality or non-disclosure (or similar) agreement between TEAC > Corporation or its affiliates and said employer, and may not be disclosed > to any other person or entity. > > > > > _______________________________________________ > music-dsp mailing list > music-dsp@music.columbia.edu > https://lists.columbia.edu/mailman/listinfo/music-dsp >
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