Apparatus and method of canceling interference

• US 7,508,864 B2
• Filed: 02/14/2005
• Issued: 03/24/2009
• Est. Priority Date: 02/14/2005
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Moshavi, Shimon, Yellin, Daniel
• Primary Examiner(s): Pathak; Sudhanshu C
• Application Number:
  US11/056,226
• Publication Number:
  US 20060209931A1
• Time in Patent Office: 1,499 Days
• Field of Search: 370/329, 370/342, 375/342, 375/147, 375/148, 375/144, 455/12.1, 455/67.3, 455/137
• US Class Current: 375/148
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception

Abstract

Briefly, a wireless communication device having a receiver includes a pilot signal interference canceller and a linear interference suppressor is provided. The pilot signal interference canceller and the linear interference suppressor jointly operate to cancel a pilot signal interference and other interference which are part of a received signal. A method for jointly cancel the interference by the pilot signal interference canceller and the linear interference suppressor is also provided.

Claims

1. A method of canceling interference in a received signal wherein the interference includes at least a pilot signal interference component and another interference signal component, the method comprising:

suppressing a linear interference according to a linear transform equation which includes;

$w=\min <br><br><br><br>E<br><br>{<br><br>s_{b_o,k_o,s_o}-w^H<br><br>\left(v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}\right)<br><br>}^2,$

where;

$v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}$

 

depicted an effective received signal with the pilot signal interference;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

A_b,pilot—

is a pilot signal transmit gain from a base station b;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

α

_b—

is a fraction of pilot signal canceled for a base station b;

w—

is a linear transform to be solved,

optimizing the linear transform equation of a linear interference suppressor based on an assumed a priori information on characteristics of the received signal and a pilot signal interference canceller operation;

jointly operating said linear interference suppressor with a pilot signal interference canceller to jointly cancel the pilot signal interference component and the other interference component of the receive signal.

2. The method of claim 1 comprising:

suppressing in a linear fashion the other interference signal component by the linear interference suppressor; and

canceling by the pilot signal interference canceller at least a portion of the pilot signal interference component by the pilot signal interference canceller.

3. The method of claim 1, comprising:

canceling the pilot signal interference by the pilot signal interference canceller before suppressing the other interference component by the linear interference suppressor.

4. The method of claim 1, comprising:

suppressing the other interference component before canceling the pilot signal interference component by the linear interference suppressor.

5. The method of claim 1 comprising:

receiving the received signal by two or more antennas; and

canceling the pilot signal interference component and other interference signal component received by at least one antenna of the two or more antennas by joint operation of the pilot interference canceller and the linear interference suppressor.

6. The method of claim 1 comprising:

receiving the received signal by two or more antennas;

canceling by the pilot signal interference canceller the pilot signal interference received by at least one antenna; and

canceling the pilot signal interference and suppressing in a linear fashion the other interference signal component received by the two or more antennas by joint operation of the pilot signal interference canceller and the linear interference suppressor.

34. The method of claim 1, wherein optimizing comprising:

optimizing the liner transform equation for jointly operation of a sample-level linear Minimum Mean Squared Error (MMSE) Multiuser detector, an equalizer and the pilot interference canceller based on an a priori assumption that at least some of the signal codes are processed by multiuser detector and at least some of the signal codes are treated randomly and processed by the equalizer to minimize the mean square error, given the existence of pilot interference cancellation.

7. A communication device comprising:

a receiver having a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized based on a priori information of an assumed received signal characteristic to the pilot signal interference canceller jointly operate with pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$w=\min <br><br><br><br>E<br><br>{<br><br>s_{b_o,k_o,s_o}-w^H<br><br>\left(v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}\right)<br><br>}^2,$

where;

$v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}$

 

depicted an effective received signal with the pilot signal interference;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

A_b,pilot—

is a pilot signal transmit gain from a base station b;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

α

_b—

is a fraction of pilot signal canceled for a base station _b; and

w—

is a linear transform to be solved.

8. The communication device of claim 7, comprising:

two or more antennas to receive the received signal, wherein the linear interference suppressor and the pilot signal interference canceller are capable of jointly operate to suppress the other interference and canceling the pilot signal interference received by at least one antenna of the two or more antennas.

9. The communication device of claim 7, comprising:

two or more antennas to receive the received signal, wherein the linear interference suppressor and the pilot signal interference canceller are capable of jointly operate to suppress the other interference and canceling the pilot signal interference received by the two or more antennas.

10. The communication device of claim 7, wherein the pilot signal interference canceller is capable of canceling the pilot signal interference before the other interference is suppressed by the linear interference suppressor.

11. The communication device of claim 7, wherein the linear interference suppressor is able to suppress the other interference before the pilot signal interference is canceled by the pilot interference canceller.

12. The communication device of claim 7 comprising:

a despreader to despread symbols of the received signal, wherein the pilot signal interference canceller is capable of canceling the pilot signal interference after despreading the symbols of the received signal and suppressing the received signal by the linear interference suppressor.

13. The communication device of claim 12, wherein the pilot signal interference and the other interference include samples and the pilot signal interference canceller is capable of canceling one or more samples of the pilot signal interference before suppressing the other interference by the linear interference suppressor and before despreading the symbols of the received signal.

14. The communication device of claim 7, wherein the linear interference suppressor comprises a minimum mean square error multiuser detector.

15. The communication device of claim 7, wherein the linear interference suppressor comprises a combined minimum mean square error multiuser detector and equalizer.

16. The communication device of claim 7, wherein the linear interference suppressor comprises a minimum mean square error equalizer.

17. The communication device of claim 7, wherein the linear interference suppressor comprises a decorrelating detector.

18. The communication device of claim 7, wherein the linear interference suppressor comprises a zero-forcing equalizer.

19. A wireless communication device comprising:

a dipole antenna to receive a received signal; and

a receiver having a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized the pilot signal interference canceller based on a priori information of an assumed received signal characteristic to jointly operate with pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$w=\min <br><br><br><br>E<br><br>{<br><br>s_{b_o,k_o,s_o}-w^H<br><br>\left(v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}\right)<br><br>}^2,$

where;

$v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}$

 

depicted an effective received signal with the pilot signal interference;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

A_b,pilot—

is a pilot signal transmit gain from a base station b;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

α

_b—

is a fraction of pilot signal canceled for a base station b; and

w—

is a linear transform to be solved.

20. The wireless communication device of claim 19, comprising:

two or more antennas to receive the received signal, wherein the linear interference suppressor and the pilot signal interference canceller are capable of jointly operate to suppress the other interference and canceling the pilot signal interference received by at least one antenna of the two or more antennas.

21. The wireless communication device of claim 19 comprising:

two or more antennas to receive the received signal, wherein the linear interference suppressor and the pilot signal interference canceller are capable of jointly operate to suppress the other interference and canceling the pilot signal interference received by the two or more antennas.

22. The wireless communication device of claim 19 comprising:

a despreader to despread symbols of the received signal, wherein the pilot signal interference canceller is capable of canceling the pilot signal interference after despreading the symbols of the received signal and suppressing the received signal by the linear interference suppressor.

23. The wireless communication device of claim 22, wherein the pilot signal interference and the other interference include samples and wherein the pilot signal interference canceller is capable of canceling one or more samples of the pilot signal interference before suppressing the other interference by the linear interference suppressor and before despreading the symbols of the received signal.

24. A wireless communication system comprising:

a wireless communication device having a receiver including a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized based on a priori information of an assumed received signal characteristic to jointly operate with the pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$w=\min <br><br><br><br>E<br><br>{<br><br>s_{b_o,k_o,s_o}-w^H<br><br>\left(v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}\right)<br><br>}^2,$

where;

$v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}$

 

depicted an effective received signal with the pilot signal interference;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

A_b,pilot—

is a pilot signal transmit gain from a base station b;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

α

_b—

is a fraction of pilot signal canceled for a base station b; and

w—

is a linear transform to be solved.

25. The wireless communication system of claim 24, comprising:

two or more antennas to receive the received signal, wherein the linear interference suppressor and the pilot signal interference canceller are capable of jointly operate to suppress the other interference and canceling the pilot signal interference received by at least one antenna of the two or more antennas.

26. The wireless communication device of claim 24 comprising:

a despreader to despread symbols of the received signal, wherein the pilot signal interference canceller is capable of canceling the pilot signal interference after despreading the symbols of the received signal and suppressing the received signal by the linear interference suppressor.

27. The wireless communication device of claim 26, wherein the pilot signal interference and the other interference include samples and wherein the pilot signal interference canceller is capable of canceling one or more samples of the pilot signal interference before suppressing the other interference by the linear interference suppressor and before despreading the symbols of the received signal.

28. An article comprising:

a storage medium, having stored thereon instructions, that when executed, result in;

suppressing a linear interference according to a linear transform equation which includes;

$w=\min <br><br><br><br>E<br><br>{<br><br>s_{b_o,k_o,s_o}-w^H<br><br>\left(v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}\right)<br><br>}^2,$

where;

$v-\underset{b=1}{\overset{B}{\sum <br><br>}}<br><br><br><br>{\mathrm{\alpha <br><br>}}_b<br><br>H_b<br><br>c_{b,o,s}<br><br>A_{b,\mathrm{pilot}}$

 

depicted an effective received signal with the pilot signal interference;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

A_b,pilot—

is a pilot signal transmit gain from a base station b;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

α

_b—

is a fraction of pilot signal canceled for a base station b;

w—

is a linear transform to be solved; and

optimizing the linear transform equation of a linear interference suppressor based on an assumed a priori information on. characteristics of the received signal to jointly operate with a pilot signal interference canceller to jointly cancel a pilot signal interference component and the other interference component of the receive signal.

29. The article of claim 28, wherein the instructions when executed result in:

suppressing in a linear fashion other interference components of the interference; and

canceling by the pilot signal interference canceller at least a portion of a pilot signal interference which is a portion of the interference.

30. The article of claim 29, wherein the instructions when executed result in:

receiving the received signal by two or more antennas; and

canceling the pilot signal interference component and other interference component received by at least one antenna of the two or more antennas by joint operation of the pilot interference canceller and the linear interference suppressor.

31. The article of claim 28, wherein the instructions when executed result in:

canceling the pilot signal interference before suppressing other interference component.

32. The article of claim 28, wherein the instructions when executed result in:

suppressing other interference component before canceling the pilot signal interference.

33. A method comprising:

providing an equation which ignores presence of a pilot signal interference, said equation depicted as;

$w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]$

Where,

w—

is a linear transform to be solve;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

(.)^H—

is indicating conjugate symmetric; and

{tilde over (v)}—

is indicting an effective received signal;

optimizing a linear transform equation of a linear interference suppressor based on an assumed a priori information on characteristics of the received signal and a pilot signal interference canceller operation; and

jointly operating said linear interference suppressor with a pilot signal interference canceller to jointly cancel the pilot signal interference component and the other interference component of the receive signal.

35. A method comprising:

optimizing a linear transform equation of a linear interference suppressor based on an assumed a priori information on characteristics of the received signal and a pilot signal interference canceller operation;

jointly operating said linear interference suppressor with a pilot signal interference canceller to jointly cancel the pilot signal interference component and the other interference component of the receive signal; and

using the linear transform equation which depicted as;

$\begin{array}{c}w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]\\ ={\left(\begin{array}{c}\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>\underset{k=1}{\overset{K}{\sum <br><br>}}<br><br><br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>p_{b,k,s}<br><br>H_b<br><br>c_{b,k,s}<br><br>c_{b,k,s}^H<br><br>H_b^H+\\ \left(1-{\mathrm{\alpha <br><br>}}_b\right)<br><br>\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>P_{b,\mathrm{Pilot}}<br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>H_b<br><br>c_{b,0,s}<br><br>c_{b,0,s}^H<br><br>H_b^H+\\ \underset{b=B_1+1}{\overset{B_1+B_2}{\sum <br><br>}}<br><br><br><br>\left(P_b-{\mathrm{\alpha <br><br>}}_b<br><br>P_{b,\mathrm{Pilot}}\right)<br><br>H_b<br><br>H_b^H+{\mathrm{\sigma <br><br>}}^2<br><br>I\end{array}\right)}^{-1}<br><br>H_b<br><br>c_{b_o,k_o,s_o}\end{array}$

Where,

E—

indicate an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

$p_{b,k,s}={<br><br>s_{b,k,s}<br><br>}^2$

 

is a transmit power of symbol ^S of user ^k for base station ^b;

P_b,Pilot—

is a transmit pilot power from base station b,

K—

is the number of users;

N_Sym—

is the number of symbols;

σ

² is an interference from other base stations;

α

_b—

is a fraction of pilot signal canceled for base station b ; and

w—

is a linear transform to be solved.

36. A communication device comprising:

a receiver having a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized based on a priori information of an assumed received signal characteristic to the pilot signal interference canceller jointly operate with pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]$

Where,

w—

is a linear transform to be solve;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

(.)^H—

is indicating conjugate symmetric; and

{tilde over (v)}—

is indicting an effective received signal.

37. A communication device comprising:

a receiver having a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized based on a priori information of an assumed received signal characteristic to the pilot signal interference canceller jointly operate with pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$\begin{array}{c}w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]\\ ={\left(\begin{array}{c}\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>\underset{k=1}{\overset{K}{\sum <br><br>}}<br><br><br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>p_{b,k,s}<br><br>H_b<br><br>c_{b,k,s}<br><br>c_{b,k,s}^H<br><br>H_b^H+\\ \left(1-{\mathrm{\alpha <br><br>}}_b\right)<br><br>\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>P_{b,\mathrm{Pilot}}<br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>H_b<br><br>c_{b,0,s}<br><br>c_{b,0,s}^H<br><br>H_b^H+\\ \underset{b=B_1+1}{\overset{B_1+B_2}{\sum <br><br>}}<br><br><br><br>\left(P_b-{\mathrm{\alpha <br><br>}}_b<br><br>P_{b,\mathrm{Pilot}}\right)<br><br>H_b<br><br>H_b^H+{\mathrm{\sigma <br><br>}}^2<br><br>I\end{array}\right)}^{-1}<br><br>H_b<br><br>c_{b_o,k_o,s_o}\end{array}$

Where,

E—

indicate an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

$p_{b,k,s}={<br><br>s_{b,k,s}<br><br>}^2$

 

is a transmit power of symbol ^S of user ^k for base station ^b;

P_b,Pilot—

is a transmit pilot power from base station b,

K—

is the number of users;

N_Sym—

is the number of symbols;

σ

² interference from other base stations;

α

_b—

is a fraction of pilot signal canceled for base station b; and

w—

is a linear transform to be solved.

38. A wireless communication device comprising:

a dipole antenna to receive a received signal; and

a receiver having a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized the pilot signal interference canceller based on a priori information of an assumed received signal characteristic to jointly operate with pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]$

Where,

w—

is a linear transform to be solve;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

(.)^H—

is indicating conjugate symmetric; and

{tilde over (v)}—

is indicting an effective received signal.

39. A wireless communication device comprising:

a dipole antenna to receive a received signal; and

a receiver having a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized the pilot signal interference canceller based on a priori information of an assumed received signal characteristic to jointly operate with pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$\begin{array}{c}w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]\\ ={\left(\begin{array}{c}\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>\underset{k=1}{\overset{K}{\sum <br><br>}}<br><br><br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>p_{b,k,s}<br><br>H_b<br><br>c_{b,k,s}<br><br>c_{b,k,s}^H<br><br>H_b^H+\\ \left(1-{\mathrm{\alpha <br><br>}}_b\right)<br><br>\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>P_{b,\mathrm{Pilot}}<br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>H_b<br><br>c_{b,0,s}<br><br>c_{b,0,s}^H<br><br>H_b^H+\\ \underset{b=B_1+1}{\overset{B_1+B_2}{\sum <br><br>}}<br><br><br><br>\left(P_b-{\mathrm{\alpha <br><br>}}_b<br><br>P_{b,\mathrm{Pilot}}\right)<br><br>H_b<br><br>H_b^H+{\mathrm{\sigma <br><br>}}^2<br><br>I\end{array}\right)}^{-1}<br><br>H_b<br><br>c_{b_o,k_o,s_o}\end{array}$

Where,

E—

indicate an expectation operation;

S_bo,koSo—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

$p_{b,k,s}={<br><br>s_{b,k,s}<br><br>}^2$

 

is a transmit power of symbol ^S of user ^k for base station ^b;

P_b,Pilot—

is a transmit pilot power from base station b,

K—

is the number of users;

N_Sym—

is the number of symbols;

σ

² is an interference from other base stations;

α

_b—

is a fraction of pilot signal canceled for base station b ; and

w—

is a linear transform to be solved.

40. A wireless communication system comprising:

a wireless communication device having a receiver including a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized based on a priori information of an assumed received signal characteristic to jointly operate with the pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]$

Where,

w—

is a linear transform to be solve;

E—

is indicating an expectation operation;

S_bo,ko,So—

is a desired symbol;

(.)^H—

is indicating conjugate symmetric; and

{tilde over (v)}—

is indicting an effective received signal.

41. A wireless communication system comprising:

a wireless communication device having a receiver including a pilot signal interference canceller and a linear interference suppressor, wherein a linear transform equation of said linear interference suppressor optimized based on a priori information of an assumed received signal characteristic to jointly operate with the pilot signal interference canceller to cancel pilot signal interference and other interference in a received signal, wherein the linear transform equation depicted as;

$\begin{array}{c}w={E<br><br>\left[\tilde{v}<br><br>{\tilde{v}}^H\right]}^{-1}<br><br>E<br><br>\left[\tilde{v}<br><br>s_{b_o,k_o,s_o}^{*}\right]\\ ={\left(\begin{array}{c}\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>\underset{k=1}{\overset{K}{\sum <br><br>}}<br><br><br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>p_{b,k,s}<br><br>H_b<br><br>c_{b,k,s}<br><br>c_{b,k,s}^H<br><br>H_b^H+\\ \left(1-{\mathrm{\alpha <br><br>}}_b\right)<br><br>\underset{b=1}{\overset{B_1}{\sum <br><br>}}<br><br><br><br>P_{b,\mathrm{Pilot}}<br><br>\underset{s=1}{\overset{N_{\mathrm{Sym}}}{\sum <br><br>}}<br><br><br><br>H_b<br><br>c_{b,0,s}<br><br>c_{b,0,s}^H<br><br>H_b^H+\\ \underset{b=B_1+1}{\overset{B_1+B_2}{\sum <br><br>}}<br><br><br><br>\left(P_b-{\mathrm{\alpha <br><br>}}_b<br><br>P_{b,\mathrm{Pilot}}\right)<br><br>H_b<br><br>H_b^H+{\mathrm{\sigma <br><br>}}^2<br><br>I\end{array}\right)}^{-1}<br><br>H_b<br><br>c_{b_o,k_o,s_o}\end{array}$

Where,

E—

indicate an expectation operation;

S_bo,ko,So—

is a desired symbol;

C_bo,ko,So—

contains chips of a desired user'"'"'s symbol;

H_b—

is a Multipath channel matrix for the base station b;

(.)^H—

is indicating conjugate symmetric;

$p_{b,k,s}={<br><br>s_{b,k,s}<br><br>}^2$

 

is a transmit power of symbol ^S of user ^k for base station ^b;

P_b-Pilot—

is a transmit pilot power from base station b,

K—

is the number of users;

N_Sym—

is the number of symbols;

σ

² is an interference from other base stations;

α

_b—

is a fraction of pilot signal canceled for base station b; and

w—

is a linear transform to be solved.