We propose frequency offset estimation and combining techniques for pilot symbol assisted (PSA) packet downlink code-division multiple access (CDMA) with multiple-input and multiple-output (MIMO) antenna systems. Orthogonal Walsh codes are used for dedicated pilot symbols at the transmit antennas. Discrete Fourier transform (DFT)-based frequency offset estimation is used for simple implementation. In addition, simple interpolation is also used for resolution improvement of the DFT. When identical frequency offset is assumed, the frequency offset estimates for each single-input single-output (SISO) sub-stream (i.e., transmit/receive antenna pair) can be combined at the receiver. Simulation results show that the estimation and combining techniques proposed here deliver improvement in the frequency offset estimation performance.
Bibliographical noteFunding Information:
Manuscript received January 22, 2002. The associate editor coordinating the review of this letter and approving it for publication was Dr. N. Van Stralen. This work was supported by Brain Korea 21 Projects, and LG Electronics.
All Science Journal Classification (ASJC) codes
- Modelling and Simulation
- Computer Science Applications
- Electrical and Electronic Engineering