ON-CHANNEL REPEATER AND ON-CHANNEL REPEATING METHOD

• US 20100221998A1
• Filed: 11/09/2007
• Published: 09/02/2010
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Park, Sung-Ik, Lee, Soo-In, Lee, Jae-Young, Kim, Heung-Mook, Eum, Ho-Min, Seo, Jae-Hyun, Lim, Jong-Soo, Lee, Yong-Tae
• Granted Patent: US 8,170,470 B2
• Time in Patent Office: Days
• US Class Current: 455/20
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 7/15585 by interference cancellation

Abstract

Provided are an on-channel repeater and method for increasing output of the on-channel repeater by removing feed-back signals caused by low isolation of transmission/reception antennas. The on-channel repeater includes: a receiver for receiving RF signals and converting the RF signals into baseband signals; a subtractor for subtracting replicas of feedback signals from the received signal; an inverse channel estimator for estimating inverse of a reception channel and generating a filter tab coefficients; a first adaptive filter for compensating for channel distortion of the subtracted signal; a transmitter for converting the signals whose channel distortion is compensated into an RF signal and performing radio transmission; a down-converter for down-converting the RF signal converted by the transmitter into the baseband signal; and a replica generator for calculating replicas and feeding back the replicas to the subtractor. The present invention is applied to the on-channel repeater.

Claims

1-13. -13. (canceled)

14. An on-channel repeating method, comprising:

receiving a Radio Frequency (RF) signal and converting the RF signal into a predetermined band signal;

subtracting a replica of feedback signals from the received signal;

estimating an inverse of a reception channel based on the signal acquired from the subtraction and generating a filter tab coefficients;

compensating for channel distortion of the signal acquired from the subtraction based on the generated filter tab coefficients;

performing radio transmission by converting the signal whose channel distortion is compensated into an RF signal; and

down-converting the RF signal acquired in the transmitting means into the predetermined band signal,

wherein the replica is calculated based on the predetermined band signal acquired from the down-conversion and the signal acquired from the subtraction and is fed back to said subtracting the replica of the feedback signal.

15. The on-channel repeating method of claim 14, wherein the replica includes:

calculating a filter tab coefficients in a time index n based on the predetermined band signal in a time index n, the signal acquired from the subtraction in the time index n, and the filter tab coefficients in a time index n−

1; and

calculating a replica based on the filter tab coefficients in the time index n and the predetermined band signal.

16. The on-channel repeating method of claim 15, wherein in said calculating the filter tab coefficients, a filter tab coefficient vector is calculated based on a Least Mean Square (LMS) algorithm.

17. The on-channel repeating method of claim 16, wherein in said calculating the filter tab coefficients, the filter tab coefficient vector h_n is calculated according to Equation 1:

h_n= h<sub>n−

1</sub>+λ

·

ε

(n)·

s_n*

h_n=[h₀(n)h₁(n) . . . h<sub>M−

1</sub>(n)]^T

h<sub>n−

1</sub>=[h₀(n−

1)h₁(n−

1) . . . h<sub>M−

1</sub>(n−

1)]^T

s_n=[s(n)s(n−

1) . . . s(n−

M+1)]^T 

 

Eq.1

where s_n is a signal vector acquired from the down-conversion into the predetermined band in the time index n;

ε

(n) is a signal acquired from the subtraction in the time index n;

λ

is a constant for determining a convergence speed;

M is the number of filter tabs;

T is a transpose; and

* is a complex conjugate.

18. The on-channel repeating method of claim 17, wherein in said calculating the replica,

the replica fb(n) is calculated according to Equation 2:

fb(n)= h_n^T·

s_n 

 

Eq. 2

19. The on-channel repeating method of claim 18, wherein in said subtracting the replica of the feedback signal,

the replica is subtracted from the predetermined band signal acquired from the said receiving RF signal and converting the RF signal according to Equation 3:

ε

(n+1)=r(n)−

fb(n) 

 

Eq. 3

where r(n) is the predetermined band signal acquired from the conversion in said receiving RF signal and converting the RF signal in the time index n; and

ε

(n+1) is a signal acquired from the subtraction in said subtracting the replica of the feedback signal in the time index n+1.

20. The on-channel repeating method of claim 14, wherein said estimating the inverse of the reception channel includes:

demodulating the signal acquired from the subtraction in said subtracting the replica of the feedback signal;

estimating channel distortion information of a repeater reception channel based on the signal acquired from the demodulation in said demodulating the signal; and

calculating an inverse of the reception channel based on the estimated channel information and generating a filter tab coefficients based on the calculated inverse of the reception channel.

21. The on-channel repeating method of claim 20, wherein said demodulating the signal includes:

removing a guard interval of the signal acquired from the subtraction in said subtracting the replica of the feedback signal;

converting the signal without a guard interval into a parallel signal; and

transforming the parallel signal into a frequency domain.

22. The on-channel repeating method of claim 20, wherein said estimating channel distortion information of the repeater reception channel includes:

extracting a pilot signal from the demodulated signal;

storing a predetermined pilot signal; and

estimating channel distortion by comparing the extracted pilot signal with the stored pilot signal.

23. The on-channel repeating method of claim 20, wherein said calculating an inverse of the reception channel and generating the filter tab coefficients includes:

generating an inverse of channel distortion based on the estimated channel distortion information; and

converting the inverse of the channel distortion into a filter tab coefficients of a time domain.

24. The on-channel repeating method of claim 14, wherein said down-converting the RF signal includes:

down-converting the RF signal acquired from the conversion in said performing radio transmission into an IF signal;

converting the IF signal into a digital IF signal; and

converting the digital IF signal into the predetermined band signal.

25. The on-channel repeating method of claim 14, wherein said receiving RF signal and converting the RF signal includes:

receiving an RF signal;

down-converting the RF signal into an IF signal;

converting the IF signal into a digital IF signal; and

converting the digital IF signal into the predetermined band signal.

26. The on-channel repeating method of claim 14, wherein said performing radio transmission includes:

converting the signal whose channel distortion is compensated in the step of compensating for channel distortion of the signal into a digital IF signal;

converting the digital IF signal converted in the step of converting the signal whose channel distortion is compensated into the digital IF signal into an analog IF signal;

up-converting the analog IF signal into an RF signal; and

amplifying the RF signal.

27. An on-channel repeater, comprising:

a receiving means for receiving a Radio Frequency (RF) signal and converting the RF signal into a predetermined band signal;

a subtracting means for subtracting a replica of feedback signals from the signal received in the receiving means;

an inverse channel estimating means for estimating an inverse of a reception channel based on the signal acquired from the subtraction in the subtracting means and generating a filter tab coefficients;

a first adaptive filtering means for compensating for channel distortion of the signal acquired from the subtraction in the subtracting means based on the filter tab coefficients generated by the inverse channel estimating means;

a transmitting means for converting the signal whose channel distortion is compensated by the first adaptive filtering means into an RF signal and performing radio transmission;

a down-converting means for down-converting the RF signal acquired in the transmitting means into the predetermined band signal; and

a replica generating means for calculating a replica based on the predetermined band signal acquired from the conversion in the down-converting means and the signal acquired from the subtraction in the subtracting means, and feeding back the replica to the subtracting means.

28-47. -47. (canceled)