  Invariable step size based least-mean-square error (ISS-LMS) was considered
as a very simple adaptive filtering algorithm and hence it has been widely
utilized in many applications, such as adaptive channel estimation. It is well
known that the convergence speed of ISS-LMS is fixed by the initial step-size.
In the channel estimation scenarios, it is very hard to make tradeoff between
convergence speed and estimation performance. In this paper, we propose an
iterative-promoting variable step size based least-mean-square error (VSS-LMS)
algorithm to control the convergence speed as well as to improve the estimation
performance. Simulation results show that the proposed algorithm can achieve
better estimation performance than previous ISS-LMS while without sacrificing
convergence speed.
