Generalized vector state-scalar observation Kalman channel estimator for doubly-selective OFDM systems

Recently, we presented a low-complexity vector state-scalar observation (VSSO) Kalman channel estimator for doubly-selective OFDM systems in [1]. In [1], we derived the decoupling equations, where a received pilot symbol vector is decoupled into L scalars, L being the number of multipaths of the channel. This decoupling concept formed the basis of the VSSO Kalman channel estimator. However, in [1], we considered only one observed subcarrier from each pilot cluster. In this paper, we consider more than one observed pilot subcarriers from each pilot cluster and work out a more generalized form of the decoupling equation. This paves way to a more generalized form of the VSSO Kalman estimator. The performance and complexity results are shown compared to an existing vector state-vector observation Kalman estimator. It will be seen that our proposed VSSO method achieves the same performance as the existing vector state-vector observation (VSVO) method [2] and results in more than 90% complexity savings. Results are also presented for a practical system like a digital video broadcasting (DVB-H) system.