# Ofdm frequency offset **URL:** \ **Category:** GNU Radio\ **Created:** [June 24, 2015, 9:33am UTC](https://www.ruby-forum.com/t/ofdm-frequency-offset/242441 "2015-06-24T09:33:26Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Post date:** [June 24, 2015, 9:33am UTC](https://www.ruby-forum.com/t/ofdm-frequency-offset/242441/1 "2015-06-24T09:33:26Z")
Dear all: Thank you in advance. 1. I want to ask a question about the new ofdm example.And I know the receiver have used the SCA(schmidl and cox algorithm) algorithm.Now in my application,maybe this algorithm isn’t enough.And I want to ask whether have other good frequency offset correction algorithm which have been implemented. 2.What is the algorithm used by the old version of the ofdm example?Thanks. Best regards, zs ---
**Author:** ![zszszs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/5fc32e/32.png) [@zszszs](https://www.ruby-forum.com/u/zszszs)\ **Post date:** [June 24, 2015, 9:55am UTC](https://www.ruby-forum.com/t/ofdm-frequency-offset/242441/2 "2015-06-24T09:55:38Z")
Dear zs, basically, Schmidl and Cox is a very good algorithm, because it can achieve the same quality of synchronization with half of the synchronization overhead compared to other approaches, or a better performance with the same amount. I must admit that from the top of my head, there’s probably not much that’s better than S&C in a real world OFDM receiver, but I must admit that I haven’t implemented many OFDM synchronizers myself. However, you say > Now in my application,maybe this algorithm isn’t enough. which means that you have a mathematical measure that’s not OK for S&C, I guess. So in what way doesn’t S&C suffice? What is it about your application that makes S&C insufficient or impossible to use? Best regards, Marcus ---
**Author:** ![zszszs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/5fc32e/32.png) [@zszszs](https://www.ruby-forum.com/u/zszszs)\ **Post date:** [June 24, 2015, 10:49am UTC](https://www.ruby-forum.com/t/ofdm-frequency-offset/242441/3 "2015-06-24T10:49:58Z")
Dear Marcus M.: Do you know which is the synchronization algorithm used in the old version of ofdm example?Where is the source code of the old ofdm version in gnuradio?Thanks. Any other suggestions? Thank you. Best regards, zs At 2015-06-24 15:54:30, “Marcus M.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Dear zs, basically, Schmidl and Cox is a very good algorithm, because it can achieve the same quality of synchronization with half of the synchronization overhead compared to other approaches, or a better performance with the same amount. I must admit that from the top of my head, there’s probably not much that’s better than S&C in a real world OFDM receiver, but I must admit that I haven’t implemented many OFDM synchronizers myself. However, you say > Now in my application,maybe this algorithm isn’t enough. which means that you have a mathematical measure that’s not OK for S&C, I guess. So in what way doesn’t S&C suffice? What is it about your application that makes S&C insufficient or impossible to use? Best regards, Marcus On 06/24/2015 09:00 AM, zs wrote: Dear all: Thank you in advance. 1. I want to ask a question about the new ofdm example.And I know the receiver have used the SCA(schmidl and cox algorithm) algorithm.Now in my application,maybe this algorithm isn’t enough.And I want to ask whether have other good frequency offset correction algorithm which have been implemented. 2.What is the algorithm used by the old version of the ofdm example?Thanks. Best regards, zs ---
**Author:** ![zszszs](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/5fc32e/32.png) [@zszszs](https://www.ruby-forum.com/u/zszszs)\ **Post date:** [June 24, 2015, 6:16pm UTC](https://www.ruby-forum.com/t/ofdm-frequency-offset/242441/4 "2015-06-24T18:16:56Z")
On 24.06.2015 01:48, zs wrote: > Dear Marcus M.: > > Do you know which is the synchronization algorithm used in the old > version of ofdm example?Where is the source code of the old ofdm version > in gnuradio?Thanks. It’s a very similar implementation to the ‘new’ versions. In stock GNU Radio, we currently don’t have other algorithms implemented, but of course, there are many available in literature that will work. Cheers, Martin