Channel estimation method and associated device for estimating channel for OFDM system

Abstract

A channel estimation method and an associated device for estimating a data channel of a data resource element are provided. The channel estimation method includes obtaining a plurality of pilot channels for pilot resource elements in a time-frequency domain, respectively; utilizing a processing circuit to apply a transformation matrix to the pilot channels, to obtain a plurality of transformed pilot channels corresponding to the pilot resource elements, respectively; and estimating the data channel of the data resource element by performing a plurality of one-dimensional channel estimations according to the transformed pilot channels.

What is claimed is: 
     
       1. A channel estimation method for estimating a data channel of a data resource element (RE), comprising:
 obtaining a plurality of pilot channels for pilot resource elements in a time-frequency domain, respectively; 
 utilizing a processing circuit to apply a transformation matrix to the pilot channels, to obtain a plurality of transformed pilot channels, respectively; and 
 estimating the data channel of the data resource element by performing a plurality of one-dimensional (1D) channel estimations according to the transformed pilot channels. 
 
     
     
       2. The channel estimation method of  claim 1 , wherein the 1D channel estimations includes a first interpolation operation in a first direction and a second interpolation operation in a second direction; one of the first direction and the second direction is a time direction of the time-frequency domain, and the other of the first direction and the second direction is a frequency direction of the time-frequency domain; and the step of estimating the data channel of the data resource element comprises:
 performing the first interpolation operation in the first direction based on the transformed pilot channels, to generate a plurality of interpolated data channels; and 
 performing the second interpolation operation in the second direction based on the interpolated data channels, to generate the data channel of the data resource element. 
 
     
     
       3. The channel estimation method of  claim 2 , further comprising:
 reusing the interpolated data channels to perform the second interpolation operation in the second direction, to generate a data channel of another data resource element, wherein the other data resource element and the data resource element are on a same axis of the second direction. 
 
     
     
       4. The channel estimation method of  claim 2 , wherein the first direction is the time direction, and the second direction is the frequency direction. 
     
     
       5. The channel estimation method of  claim 2 , wherein the first direction is the frequency direction, and the second direction is the time direction. 
     
     
       6. A channel estimation device, arranged for estimating a data channel of a data resource element (RE), the channel estimation device comprising:
 a pilot channel estimator, arranged to obtain a plurality of pilot channels for pilot resource elements in a time-frequency domain, respectively; 
 a processing circuit, arranged to apply a transformation matrix to the pilot channels, to obtain a plurality of transformed pilot channels, respectively; and 
 a data channel estimator, arranged to estimate the data channel of the data resource element by performing a plurality of one-dimensional (1D) channel estimations according to the transformed pilot channels. 
 
     
     
       7. The channel estimation device of  claim 6 , wherein the 1D channel estimations includes a first interpolation operation in a first direction and a second interpolation operation in a second direction; one of the first direction and the second direction is a time direction of the time-frequency domain, and the other of the first direction and the second direction is a frequency direction of the time-frequency domain; the data channel estimator is used to perform the first interpolation operation in the first direction based on the transformed pilot channels to generate a plurality of interpolated data channels, and perform the second interpolation operation in the second direction based on the interpolated data channels to generate the data channel of the data resource element. 
     
     
       8. The channel estimation device of  claim 7 , wherein the interpolated data channels are reused to perform the second interpolation operation in the second direction, to generate a data channel of another data resource element; and the other data resource element and the data resource element are on a same axis of the second direction. 
     
     
       9. The channel estimation device of  claim 7 , wherein the first direction is the time direction, and the second direction is the frequency direction. 
     
     
       10. The channel estimation device of  claim 7 , wherein the first direction is the frequency direction, and the second direction is the time direction. 
     
     
       11. A channel estimation method for estimating a data channel of a data resource element (RE), comprising:
 obtaining a plurality of pilot channels for pilot resource elements in a time-frequency domain, respectively; 
 utilizing a processing circuit to use the plurality of pilot channels for pilot resource elements to obtain a plurality of reference channels, respectively; and 
 estimating the data channel of the data resource element by performing a one-dimensional (1D) channel estimation according to the reference channels. 
 
     
     
       12. The channel estimation method of  claim 11 , wherein the 1D channel estimation is a time direction interpolation. 
     
     
       13. The channel estimation method of  claim 12 , wherein the reference channels and the data resource element are on a same axis of the time direction. 
     
     
       14. The channel estimation method of  claim 11 , wherein the 1D channel estimation is a frequency direction interpolation. 
     
     
       15. The channel estimation method of  claim 14 , wherein the reference channels and the data resource element are on a same axis of the frequency direction. 
     
     
       16. A channel estimation device, arranged for estimating a data channel of a data resource element (RE), the channel estimation device comprising:
 a pilot channel estimator, arranged to obtain a plurality of pilot channels for pilot resource elements in a time-frequency domain, respectively; 
 a processing circuit, arranged to use the plurality of pilot channels for pilot resource elements to obtain a plurality of reference channels, respectively; and 
 a data channel estimator, arranged to estimate the data channel of the data resource element by performing a one-dimensional (1D) channel estimation according to the reference channels. 
 
     
     
       17. The channel estimation device of  claim 16 , wherein the 1D channel estimation is a time direction interpolation. 
     
     
       18. The channel estimation device of  claim 17 , wherein the reference channels and the data resource element are on a same axis of the time direction. 
     
     
       19. The channel estimation device of  claim 16 , wherein the 1D channel estimation is a frequency direction interpolation. 
     
     
       20. The channel estimation device of  claim 19 , wherein the reference channels and the data resource element are on a same axis of the frequency direction.