Parameter estimation for an asynchronous CV-CCMA system

This paper describes an algorithm that overcomes the problem of lack of synchronisation of transmissions from two users or more in a complex-valued collaborative coding multiple access system (CV-CCMA). The receiver performs estimation of both, the complex gain coefficients and the delay associated with each user path. A maximum likelihood formulation is employed for data detection and the estimation of the channel parameters. The CV-CCMA requires strict synchronisation of transmissions from each of the users whereas the proposed algorithm relaxes this constraint. An example of a two user system is presented