Hi, I am simulating equalizer with Reed-Solomon channel code a frequency fading channel. The fading channel has a severe spectral null, I use frequecy domain equalization to contre the null. At present I think the equalizer works well. When I add the RS(170,180) (8 bit) channel code for a data frame, I find the BER performance is not improved at all. It is even worse a little bit than that of without channel code. I know I have to account for the confidence level. All in all, the results are very similar. When I control the channel to generate shorter consecutive errors, i.e. not as severe as the first one, I can see some improvements. My question is: for a severe fading channel (not AWGN), a short t (error corection length t/2) RS code would not improve the performance? Or, it should absolutely improve the BER? I cannot find any error until now. Thanks in advance
Question about Reed-Solomon error control code
Started by ●April 4, 2005
Reply by ●April 4, 20052005-04-04
>>>>> "freelait2000" == freelait2000 <freelait2000@yahoo.com> writes:freelait2000> I am simulating equalizer with Reed-Solomon channel code a frequency freelait2000> fading channel. The fading channel has a severe spectral null, I use freelait2000> frequecy domain equalization to contre the null. At present I think the freelait2000> equalizer works well. When I add the RS(170,180) (8 bit) channel code freelait2000> for a data frame, I find the BER performance is not improved at all. It freelait2000> is even worse a little bit than that of without channel code. I know I freelait2000> have to account for the confidence level. All in all, the results are freelait2000> very similar. When I control the channel to generate shorter freelait2000> consecutive errors, i.e. not as severe as the first one, I can see some freelait2000> improvements. freelait2000> My question is: for a severe fading channel (not AWGN), a short t freelait2000> (error corection length t/2) RS code would not improve the performance? freelait2000> Or, it should absolutely improve the BER? I cannot find any error until freelait2000> now. I think you can answer this if you know how long the average fade length of your fading channel is. If your average fade length is t/2 symbols long or more, the RS code won't be able to correct anything, so performance may be the same or worse than if you had no RS code at all. There's a lot of handwaving here, but I think it gets to the point. Ray
Reply by ●April 4, 20052005-04-04