Journal of Applied Sciences ›› 2017, Vol. 35 ›› Issue (6): 693-705.doi: 10.3969/j.issn.0255-8297.2017.06.003

• Communication Engineering • Previous Articles     Next Articles

Joint Angle and Delay Estimation for OFDM Using Unitary Transform and Structured Least Squares

GUO Li-kai, WU Ying, YIN Jie-xin, WANG Cheng   

  1. Institute of Information System Engineering, Information Engineering University, Zhengzhou 450001, China
  • Received:2016-12-07 Revised:2016-12-22 Online:2017-11-30 Published:2017-11-30

Abstract:

In an orthogonal frequency division multiplexing (OFDM) system, traditional subspace-based joint angle and delay estimation algorithms show significant performance degradation at low signal-to-noise ratio (SNR). To solve the problem, a new algorithm using unitary transform and structured least squares (SLS) is proposed. With unitary transform, data are transformed to the real number domain. Two-dimensional SLS is then used to estimate two real-valued diagonal matrices that contain information of angles and delays. A complex matrix is constructed with the two real-valued matrices, and eigenvalues of the complex matrix are calculated. The real and imaginary parts of the eigenvalues correspond to angles and delays, respectively. Since SLS takes into account the coupling relationship between noise terms and restores the estimated signal subspace matrix, its estimation performance is closer to optimum than those of the others. Simulation results show that the proposed USLS-JADE algorithm is superior to traditional subspace-based algorithms in terms of accuracy and success rate.

Key words: wireless communications, joint angle and delay estimation (JADE), structured least squares (SLS), orthogonal frequency division multiplexing (OFDM)

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