in OFDM systems, the LS channel estimation result should be H'=P'/P if we compensate the received data symbols with one tap scheme, the equalization result should be D''=D'/H' = P*D'/P'; one the right of the above equation, D'/P' looks like the differential decoding result so the coherent demodulation with LS estimation and onetap equalization sees like the differential demodulation. but why the coherent modulation is so popular in OFDM system.
a question about the effect of channel estimation and equalization in ofdm
Started by ●June 24, 2009
Reply by ●June 24, 20092009-06-24
On Jun 24, 9:39=A0am, "MrJiang" <misterji...@126.com> wrote:> in OFDM systems, the LS channel estimation result should be > > H'=3DP'/P > > if we compensate the received data symbols with one tap scheme, the > equalization result should be > > D''=3DD'/H' =3D P*D'/P'; > > one the right of the above equation, D'/P' looks like the differential > decoding result > > so the coherent demodulation with LS estimation and onetap equalization > sees like the differential demodulation. > > but why the coherent modulation is so popular in OFDM system.It's because if you really think about it, A=3DA'/B, so therefore B''=3DB'/ C.
Reply by ●June 25, 20092009-06-25
>On Jun 24, 9:39=A0am, "MrJiang" <misterji...@126.com> wrote: >> in OFDM systems, the LS channel estimation result should be >> >> H'=3DP'/P >> >> if we compensate the received data symbols with one tap scheme, the >> equalization result should be >> >> D''=3DD'/H' =3D P*D'/P'; >> >> one the right of the above equation, D'/P' looks like the differential >> decoding result >> >> so the coherent demodulation with LS estimation and onetapequalization>> sees like the differential demodulation. >> >> but why the coherent modulation is so popular in OFDM system. > >It's because if you really think about it, A=3DA'/B, so thereforeB''=3DB'/>C. >sorry, I can't get your meaning. could you explain it?
Reply by ●June 26, 20092009-06-26
>On Jun 24, 9:39=A0am, "MrJiang" <misterji...@126.com> wrote: >> in OFDM systems, the LS channel estimation result should be >> >> H'=3DP'/P >> >> if we compensate the received data symbols with one tap scheme, the >> equalization result should be >> >> D''=3DD'/H' =3D P*D'/P'; >> >> one the right of the above equation, D'/P' looks like the differential >> decoding result >> >> so the coherent demodulation with LS estimation and onetapequalization>> sees like the differential demodulation. >> >> but why the coherent modulation is so popular in OFDM system. > >It's because if you really think about it, A=3DA'/B, so thereforeB''=3DB'/>C. >sorry, I can't get your meaning. could you explain it?
Reply by ●June 26, 20092009-06-26
>>On Jun 24, 9:39=A0am, "MrJiang" <misterji...@126.com> wrote: >>> in OFDM systems, the LS channel estimation result should be >>> >>> H'=3DP'/P >>> >>> if we compensate the received data symbols with one tap scheme, the >>> equalization result should be >>> >>> D''=3DD'/H' =3D P*D'/P'; >>> >>> one the right of the above equation, D'/P' looks like thedifferential>>> decoding result >>> >>> so the coherent demodulation with LS estimation and onetap >equalization >>> sees like the differential demodulation. >>> >>> but why the coherent modulation is so popular in OFDM system. >> >>It's because if you really think about it, A=3DA'/B, so therefore >B''=3DB'/ >>C. >> > >sorry, I can't get your meaning. >could you explain it? >Please specify what H, D and P are.
