Fast Kalman Equalization for Cooperative Relay Networks With Both Time and Frequency Offsets
Cooperative relay networks are asynchronous inherently both in time and frequency due to their distributed nature. In this paper, the authors propose a transceiver scheme to combat both time and frequency offsets for cooperative relay networks. At the relay nodes, the distributed linear convolutional space-time coding is adopted to achieve the time-asynchronous full cooperative diversity. This transmission scheme leads to an equivalent channel with special structure at the destination node. By taking full advantage of this special structure, fast Kalman equalizations based on Linear Minimum Mean Square Error (LMMSE) and MMSE decision feedback equalizers are proposed for the receiver, where the estimation of the state vector (information symbols) can be operated recursively and computationally efficient.