data aided phase estimation

Started by elbib00 in comp.dsp15 years ago 5 replies

i m currently on a project that requires me to do symbol to symbol phase estimation. was using the non data aided viterbi&viterbi...

i m currently on a project that requires me to do symbol to symbol phase estimation. was using the non data aided viterbi&viterbi algorithm unfortunately i wasnt able to meet the specs of the project. was wondering if there is any data aided algorithm via pilots that is able to achieve enhanced performance? cheers This message was sent using the Comp.DSP web interface on www.DSPRelated.co...


soft output viterbi

Started by S.Diwakar in comp.dsp11 years ago 2 replies

Hi, I very well understand the advantages of soft input being used for viterbi decoding but, i fail to understand what is the use of soft...

Hi, I very well understand the advantages of soft input being used for viterbi decoding but, i fail to understand what is the use of soft output? How is this soft output generated and how is it useful.If its iterative decoding then we can use this output softbits for further decoding. please let me know how to generate the soft-output and the use of it. Rgds, S.Diwakar. _____...


ACS block in soft decision viterbi

Started by san_jack in comp.dsp10 years ago

Hi all, I want to implement soft decision viterbi decoder in FPGA. I have already implemented hard-decision decoding and the design works fine...

Hi all, I want to implement soft decision viterbi decoder in FPGA. I have already implemented hard-decision decoding and the design works fine in xilinx FPGA. We have implemented "high bit clear circuit" for path metrics normalization to reduce the area. Now, i want to implement soft-decision decoding an I need to change the BMU and ACS modules in my code. One thing that worries me is the ...


BFSK with Viterbi vs 16FSK with Viterbi

Started by JAlbertoDJ in comp.dsp13 years ago 3 replies

** BER for a FSK noncoherent is PE=(M-1)/2 * exp(-Es/2No) => PE= (16-1)/2 * exp(-Es/2No) BER= PE*(M/2)/(M-1)=> BER= PE*8/15 BER=...

** BER for a FSK noncoherent is PE=(M-1)/2 * exp(-Es/2No) => PE= (16-1)/2 * exp(-Es/2No) BER= PE*(M/2)/(M-1)=> BER= PE*8/15 BER= 4 * exp(-Es/2No) ** BER for a BFSK noncoherent is BER= 1/2 * exp(-Es/2No) So, BER for 16FSK is 8 times BER for BFSK. But, after Viterbi in both cases, will be the different between both modulations 8 times?


Regarding Viterbi decoder of continuous transmission?

Started by news reader in comp.dsp12 years ago 6 replies

I am reading Viterbi decoding technique, and confused with the trace back. Assume rate 1/2 K=3 convolutional encoding. When the trace back...

I am reading Viterbi decoding technique, and confused with the trace back. Assume rate 1/2 K=3 convolutional encoding. When the trace back depth is 5K. Is the trace back operation performed in blocks of 5K bits and decode 5K bits at a time, or trace back operation is performed on a 5K FIFO which stores the state history, and decode the single bit in the beginning of the state history FIF...


Decode QPSK convolutional encoded symbols using viterbi soft decoding

Started by ssohaib in comp.dsp12 years ago

Hi, Can anyone plz tell me how to decode QPSK convolutional encoded symbols using viterbi soft decoding? I know we have to find the Eucledian...

Hi, Can anyone plz tell me how to decode QPSK convolutional encoded symbols using viterbi soft decoding? I know we have to find the Eucledian distance but plz tell me all the steps i should follow to decode it. Regards, Sarmad


Convolutional coding - block lenght

Started by Melinda in comp.dsp11 years ago 4 replies

Hi, Does anyone knows does block length of info data, which then goes through convolutional encoder(convolutional encoding), has impact of...

Hi, Does anyone knows does block length of info data, which then goes through convolutional encoder(convolutional encoding), has impact of performance on convolutional coding and Viterbi decoding(FEC system). For example if info message length is 256 bits, or 1024 bits, or 8912 bits does performance of FEC system(convolutional encoding and Viterbi decoding) changes with different input block l...


Re:Block viterbi decoding

Started by san_jack in comp.dsp10 years ago

Hi, I referred xilinx application note. But there is no such information given

Hi, I referred xilinx application note. But there is no such information given


New algorithms in MLSE?

Started by Verictor in comp.dsp6 years ago 6 replies

Hi, Anyone is aware of state search algorithms in MLSE (maximum likelihood sequence equalization) other than the Viterbi? Thanks

Hi, Anyone is aware of state search algorithms in MLSE (maximum likelihood sequence equalization) other than the Viterbi? Thanks


Serial List Viterbi Algorithm

Started by sl209675 in comp.dsp6 years ago

Hello, I was wondering if anyone knows a link to an article and/or paper which graphically describes the SLVA, preferably through an example. I...

Hello, I was wondering if anyone knows a link to an article and/or paper which graphically describes the SLVA, preferably through an example. I have read through the IEEE papers on it, but wanted to see step by step diagrams of how the N-best paths are selected (not just the analytical analysis). _____________________________ Posted through www.DSPRelated.com


Theoretical BER

Started by Michael B. in comp.dsp13 years ago 2 replies

Hi guys, I need to fing plots (or equations) for the theoretical BER for some error correction codes: Reed-Solomon, Turbo Codes, Viterbi,...

Hi guys, I need to fing plots (or equations) for the theoretical BER for some error correction codes: Reed-Solomon, Turbo Codes, Viterbi, CRC-8. Could someone please point me out where can I find this. Michael B.


non - binary sova

Started by filipo in comp.dsp13 years ago

Hi, I have this kind of a problem. I don't know how to implement soft output viterbi algorithm for non-binary (over ring) codes. What should...

Hi, I have this kind of a problem. I don't know how to implement soft output viterbi algorithm for non-binary (over ring) codes. What should the the extrinsic information contain and how to compute and process it??. I went through many papers relating sova and non binary case, but still I?m stuck. Thank You Filip


Viterbi distance measure

Started by Anonymous in comp.dsp15 years ago 8 replies

Hi, Can someone help in proving/disproving the following? if (a^2 > b^2) then |a| > |b|. can it be extended to say that if (a^2 +...

Hi, Can someone help in proving/disproving the following? if (a^2 > b^2) then |a| > |b|. can it be extended to say that if (a^2 + b^2) > (c^2 + d^2) then ( |a| + |b| ) > ( |c| + |d| ) This is to check if an euclidean distance measure can be replaced by an absolute distance measure? Thanks, Raju


OFDM BER Measure

Started by enginm in comp.dsp14 years ago 1 reply

Hello, Does anyone know how to estimate the BER of a Viterbi decoder when p = |H|^2 * |r-x|^2 is used as the decision metric ? Thanks...

Hello, Does anyone know how to estimate the BER of a Viterbi decoder when p = |H|^2 * |r-x|^2 is used as the decision metric ? Thanks for your cooperation. Engin |H|^2 = Channel's kth coefficient in frequency domain r = received symbol x = transmitted symbol This message was sent using the Comp.DSP web interface on www.DSPRelated.com


When does ML (Viterbi) gives MAP performance?

Started by KK in comp.dsp15 years ago 3 replies

Greetings, I always assumed that MAP and ML performances differ, with former being superior. However, under certain conditions ML approaches...

Greetings, I always assumed that MAP and ML performances differ, with former being superior. However, under certain conditions ML approaches MAP performance. I know of trivial case when the variables to be decoded are uncorrelated, ML is MAP. I am interested in knowing about other cases when this is true. Could anyone throw some light on this issue? Regards, KK


CPFSK receiver architecture

Started by gct in comp.dsp2 years ago 12 replies

I'm evaluating receiver structures for the ETSI DMR spec, but not having much luck finding any work in this area. They use continuous...

I'm evaluating receiver structures for the ETSI DMR spec, but not having much luck finding any work in this area. They use continuous phase modulation, so I anticipate I'll have to use a viterbi demodulator to get it done. Unfortunately they choose h=.27, so I have at least 200 states, times whatever number of symbol cycles their pulse shape is over (not clear on this, three maybe?). So I'm loo...


CPFSK synchronization.

Started by ajith shenoy in comp.dsp6 years ago 3 replies

Hello, I am trying to demodulate a binary CPFSK with modulation index of 0.6 With correlation receiver & viterbi decoder I am able to...

Hello, I am trying to demodulate a binary CPFSK with modulation index of 0.6 With correlation receiver & viterbi decoder I am able to demodulate a synchronized signal, but i am stuck with synchronization techniques. Can anyone please let me know any ideas for synchronization. Thanks & Regards, Ajith


ML equalizer

Started by sair...@gmail.com in comp.dsp13 years ago

Hi, I am working on equalization schemes without using Viterbi type of algorithms. Assume that complexity is not an issue. I am trying...

Hi, I am working on equalization schemes without using Viterbi type of algorithms. Assume that complexity is not an issue. I am trying to detect the received samples using ML equation. Mathematically , if a1, a2, a3 .. aN are the input symbols, say h1, h2, h3 are the channel tap gains. Then the received signal is represented in vector fom as R= A*h+n, where R is the received vector...


viterbi traceback - continuous data mode

Started by Anonymous in comp.dsp15 years ago 9 replies

Another quick question about the VA... How do I do traceback for continuous mode data? Suppose, for a 4 state trellis, the total survivor...

Another quick question about the VA... How do I do traceback for continuous mode data? Suppose, for a 4 state trellis, the total survivor history is eg. t = 0 1 2 3 4 5 6 7 8 9 10 ---------------------------------------------------------------------- 0 0 1 0 1 1 0 1 0 0 1 2 2 2 3 3...


Viterbi decoding

Started by Elnaz in comp.dsp8 years ago 1 reply

I am using "vitdec" in Matlab with 'trunc' and 'unquant' propoerties for decoding real-valued data in between almost -2.5 and 2.5 (i.e. binary...

I am using "vitdec" in Matlab with 'trunc' and 'unquant' propoerties for decoding real-valued data in between almost -2.5 and 2.5 (i.e. binary values with interference and noise). The interesting problem is that I'm having intervals of %100 correct detections and %100 wrong decisions (bits are flipped) in my decoded stream. It's like the detector changes sign and switches between two interval...