Signal detection under noise

Discussion in 'Programmer's Corner' started by zico, Jan 9, 2007.

  1. zico

    Thread Starter New Member

    Jan 9, 2007
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    Hi everybody..I am looking for the matlab code about the signal detection under noise or any info related to this topic.
    Can anyone help me??? I will be greatful...:rolleyes:
    thanks anyway!!
     
  2. Dave

    Retired Moderator

    Nov 17, 2003
    6,960
    143
    Matlab code about the signal detection under noise is a touch vague. You obviously have a signal contaminated with noise and wish to filter the noise component using a suitable filter-design.

    Perhaps you should tell us a little about the signal and noise - is it wideband noise on a narrowband signal, or vice versa? Is the noise component (frequency band) embedded within the signal frequency? What filter do you think may be suitable based on the answers to these questions, IIR, FIR, Adaptive? Are you proficient in DSP filter design? If so, tell us a little bit (qualitatively) about how you propose to tackle this problem.

    Dave
     
  3. zico

    Thread Starter New Member

    Jan 9, 2007
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    thanks for your concern!!I really don't know about the DSP design and bad at matlab.Any code about the signal detection could help me it can be about wideband noise on a narrowband signal.I have to show something to my teacher.I need your suggestions I'm a hopeless case :))
    H-E-L-P thanks again!!Take care....
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Hi,

    It's really hard to guess anout the nature of the signal and noise, which is quite significant to a reply. You might look at "lock-in amplifiers" and see if NASA has any material about how they manage to stay in contact with robotic spacecraft like Pioneer that transmit about 1 watt power and are hundreds of millions of miles distant. That signal is probably over 100 dB down in the noise and suffers doppler shilt as well.
     
  5. Dave

    Retired Moderator

    Nov 17, 2003
    6,960
    143
    From my initial response I assumed (mainly because this is a Matlab question) that you were looking at filtering noise from a recieved (detected) signal - now I'm not sure what you're asking given that you don't know much about DSP design (the core concept behind filtering). Several points:

    1) You need to clarify what you are trying to achieve based on what I have said above.
    2) You need to tell us more about the nature of the signal and noise. Without this, we are lost as to provide any input.
    3) If you're expecting me give you code, I'm afraid I don't have any for either of these applications, I personally can only offer advice and guidance.

    Dave
     
  6. zico

    Thread Starter New Member

    Jan 9, 2007
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    0
    what i mean is the program will take binary coded signal like [0 1 1 0] then convert this signal to digital signal by encoder.after signal is modulated the program adds noise to the signal.Signal+noise is demodulated then converted to binary coded signal by decoder.The program should adjust the noise level.At the end the program should compare the input binary code and output binary code for any errors.But I can't write the code in Matlab.I don't have enough knowledge.Can you help me?
     
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