<p>The oversampling based channel estimation with time domain decorrelation (OCE-TDD) is proposed in this paper for channel with colored noise and interference. In OCE-TDD, the training vectors are transmitted in the fashion that has the same bandwidth and the same energy as those in conventional training-based channel estimation, but the received signal is sampled with the sampling rate that is <i>a</i> times the symbol rate (<InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="34_2025_3025_Article_IEq1.gif" Format="GIF" Height="15" Rendition="HTML" Resolution="72" Type="Linedraw" Width="41" /> </InlineMediaObject> <EquationSource Format="TEX">\(a \ge 1\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>a</mi> <mo>≥</mo> <mn>1</mn> </mrow> </math></EquationSource> </InlineEquation>) and a transformation is imposed on the samples so that colored noise and interference are decorrelated in time domain. The case where there are <i>b</i> independent interfering symbols for each symbol period is considered and it is shown that if <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="34_2025_3025_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="69" /> </InlineMediaObject> <EquationSource Format="TEX">\(a \ge b + 1\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>a</mi> <mo>≥</mo> <mi>b</mi> <mo>+</mo> <mn>1</mn> </mrow> </math></EquationSource> </InlineEquation>, then the effect of interference can be eliminated by increasing <i>a</i>. This result implies that the effect of interference can be eliminated by OCE-TDD without consuming excess bandwidth or excess energy. It is also shown that with OCE-TDD, the channel estimation error for the case with colored noise is smaller than the channel estimation error for the case with white noise.</p>