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about the frequency offset RRS feed

  • Question

  • Hi all,

    I roughly calculate the frequency offset between transfer and receiver. And the result is about 1KHz.I want to ask if this result is acceptable?

    What is the theoretical range of the value on the USRP RF board?

    thanks

    Friday, October 29, 2010 10:34 AM

Answers

  • Hi Alert,

    1KHz frequency offset is very good in practice (from enginnering point of vew). It is good for most of wireless protocols that are used today.

    Such offset may change board-by-board, and also change based on the working environment (e.g. temporature).

    So for many wireless receivers, you need to correct such offset using digital signal processing algorithms. You may find substantial discussion on these algorithms in many wireless communication books.

    - Kun

    • Marked as answer by Kun Tan Sunday, October 31, 2010 9:00 AM
    Sunday, October 31, 2010 4:35 AM

All replies

  • Hi Alert,

    1KHz frequency offset is very good in practice (from enginnering point of vew). It is good for most of wireless protocols that are used today.

    Such offset may change board-by-board, and also change based on the working environment (e.g. temporature).

    So for many wireless receivers, you need to correct such offset using digital signal processing algorithms. You may find substantial discussion on these algorithms in many wireless communication books.

    - Kun

    • Marked as answer by Kun Tan Sunday, October 31, 2010 9:00 AM
    Sunday, October 31, 2010 4:35 AM
  • Thanks for your replying.And I want to ask another question.Which Crystal Oscillator causes the offset? On the RCB board or on the RF daughterboard? I think that this frequency offset is from the RF. The Crystal Oscillators between the TX and RX exist small offset on timing. So I want to ask if my assumption is acceptable.
    Tuesday, November 2, 2010 1:36 AM
  • Yes. The frequency offset comes from the difference between the TX and RX oscillators. There exists both offsets in frequency as well as phase.

    - Kun

    Tuesday, November 2, 2010 9:23 AM