Communication Method for Estimating Doppler Spread

• US 20130230128A1
• Filed: 09/04/2012
• Published: 09/05/2013
• Est. Priority Date: 03/05/2012
• Status: Abandoned Application

• Current Assignee: National Tsing Hua University
• Original Assignee: National Tsing Hua University
• Inventors: Tsai, Chia-Hung, Tsai, Yuh-Ren, Yang, Kai-Jie, Wang, Chin-Liang
• Application Number:
  US13/602,799
• Publication Number:
  US 20130230128A1
• Time in Patent Office: Days
• US Class Current: 375/341
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2671 Time domain
• CPC Class Codes: H04L 27/2675 Pilot or known symbols
• CPC Class Codes: H04L 27/2684 Complexity
• CPC Class Codes: H04L 27/2692 with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver

Abstract

A communication method for estimating Doppler spread includes the following steps: transmitting a preamble signal to a receiver from a transmitter of a transmission terminal. The preamble signal is received by the receiver; followed by dividing the received samples in the preamble signal into a plurality of sets of samples. The plurality of sets of samples are introduced into a Doppler spread estimation algorithm to estimate Doppler spread.

Claims

1. A communication method for estimating Doppler spread, comprising:

transmitting a preamble signal to a receiver from a transmitter;

receiving said preamble signal by said receiver;

dividing received samples in said preamble signal into a plurality of sets of samples; and

introducing said plurality of sets of samples into a Doppler spread estimation algorithm to estimate Doppler spread.

2. The method of claim 1, wherein said Doppler spread estimation algorithm comprises a preamble-based maximum likelihood estimation algorithm, and the step of introducing said plurality of sets of samples into a Doppler spread estimation algorithm comprises introducing a total log-likelihood result of said plurality of sets of samples into said Doppler spread estimation algorithm.

3. The method of claim 2, before the step of introducing a total log-likelihood result of said plurality of sets of samples into said preamble-based maximum likelihood estimation algorithm, further comprising:

respectively introducing said plurality of sets of samples into a log-likelihood equation to obtain a plurality of log-likelihood results and summing up said plurality of log-likelihood results to obtain said total log-likelihood result.

4. The method of claim 3, wherein said log-likelihood equation is

L(ƒ

_d;

y_p,m^(u))=log[det(C_m,m^(u))]+(y_p,m^(u))^H (C_m,m^(u))<sup>−

1</sup>y_p,m,

wherein ƒ

_d denotes maximum Doppler spread, u denotes starting index and is an integer which is not less than 0, y_p,m denotes partial samples in said received samples in said preamble signal corresponding to an mth symbol, and C_m,m denotes auto-covariance matrix of said partial samples in said received samples corresponding to said mth symbol.

5. The method of claim 2, wherein said preamble-based maximum likelihood estimation algorithm is

6. The method of claim 1, wherein the step of dividing received samples in said preamble signal into a plurality of sets of samples comprises:

acquiring uth sample in said received samples of said preamble signal as 1st sample in uth set of samples; and

acquiring u+Pth sample, u+2Pth sample to u+NPth sample in said received samples of said preamble signal in order until all said received samples of said preamble signal to complete said uth set of samples, wherein P is a positive integer, u is an integer which is not less than 0, and N is an integer greater than 2.

7. The method of claim 1, wherein the step of dividing received samples in said preamble signal into a plurality of sets of samples comprises:

acquiring uth sample in said received samples of said preamble signal as 1st sample in uth set of samples; and

acquiring u+Pth sample and u+2Pth sample in said received samples of said preamble signal in order to complete said uth set of samples, wherein P is a positive integer and u is an integer which is not less than 0.

8. The method of claim 1, wherein the step of dividing received samples in said preamble signal into a plurality of sets of samples comprises:

acquiring uth sample in said received samples of said preamble signal as 1st sample in uth set of samples; and

acquiring u+Pth sample in said received samples of said preamble signal to complete said uth set of samples, wherein P is a positive integer and u is an integer which is not less than 0.

9. The method of claim 1, wherein P−

1 zeros are included between any two nonzero samples of said transmitted preamble signal, wherein P is a positive integer.