Abstract: A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).

Abstract: A system and method for handling a digital electronic flow between a first and second entity in which a flow policy is determined that is to be applied to the flow and the flow is then directed along a path in accordance with the policy. An ID is supplied for each flow and a tag associated with each flow which indicates the policy to be applied to its associated flow. Flows are also associated with one another, with associated flows having associated policies. In particular the flow may be processed or forwarded. The path may include a graph structure and virtual applications.