摘要

A novel generalized channel estimation scheme without the need of matrix inversion or iterative operations is proposed for single input single output (SISO)/multiple input single output (MISO) digital terrestrial multimedia broadcasting (DTMB) system, adopting the time-domain synchronous orthogonal frequency division multiplexing technology. Simultaneously exploiting time domain correlation channel estimation and the constant coefficients of the imperfect autocorrelation of m-sequence, a simple and generalized closed-form solution related to each channel tap can be acquired by solving the constructed linear equations. On the basis of the specified frame head structure for the SISO DTMB system, quasi-orthogonal frame head sequences over multiple antennas are designed by employing different cyclic shifts of m-sequence. In addition, in order to effectively recover the transmitted signal in the frequency domain, the tail cancelation and cyclic reconstruction process is elaborated primarily for MISO systems. It is shown that, for the SISO DTMB system, the implementation complexity of the intersymbol interference cancelation (ISIC) of the proposed approach is reduced by approximately 90% over the existing iterative scheme, and for the MISO DTMB system, the implementation complexity of the proposed scheme with the co-channel interference cancelation (CCIC) and ISIC dramatically decreases compared with the existing scheme. Simulation results validate that the proposed channel estimation scheme can achieve almost the same performance as the existing channel estimation methods, but with a significant reduction in computational complexity in both SISO and MISO DTMB systems.