Systems and techniques are disclosed relating to communications. The systems and techniques involve transmitting a signal over a plurality of time periods, receiving a plurality of parameters each relating to the signal transmission during a different one of the time periods, filtering a first one of the parameters to generate a first filtered parameter, filtering a second one of the parameters as a function of the first filtered parameter to generate a second filtered parameter, and adjusting the signal as a function of the second filtered parameter. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.