Equalizing method in a receiver node of a wireless communication system

Patent metadata

Field	Value
Publication number	US-9485002-B2
Application number	US-201314068607-A
Country	US
Kind code	B2
Filing date	Oct 31, 2013
Priority date	Oct 31, 2013
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

The present invention relates to an equalizing method in a receiver node of a cellular wireless communication system, the method comprising: receiving at least one radio signal comprising a plurality of resource elements; obtaining interference information associated with the plurality of resource elements; extracting resource elements from the plurality of resource elements carrying data into a first set based on the interference information; dividing the resource elements in the first set into one or more sub-sets each comprising T number of resource elements; filtering the resource elements in said one or more sub-sets by applying a balanced whitening and energy focusing filter W so as to obtain filtered resource elements y; and equalizing the filtered resource elements y. The invention also relates to a receive device, a computer program, and a computer program product.

First claim

The invention claimed is:

1. Equalizing method in a receiver of a cellular wireless communication system, the method comprising:
receiving at least one radio signal comprising a plurality of resource elements;
obtaining interference information associated with the plurality of resource elements;
extracting resource elements from the plurality of resource elements carrying data into a set based on the interference information, the set including resource elements affected by interference from among resource elements of the plurality of resource elements unaffected by interference;
dividing the resource elements in the set into one or more sub-sets comprising T number of resource elements, the one or more sub-sets being formed to correlate with interference;
filtering the resource elements in said one or more sub-sets using a balanced whitening and energy focusing filter W and obtaining filtered resource elements y; and
equalizing the filtered resource elements y using at least one detector configured to handle L Multiple Input Multiple Output (MIMO) layers in the receiver of the cellular wireless communication system from among the plurality of resource elements including the resource elements unaffected by interference which are comprised in radio signals of different channels and pilot symbols received over a MIMO radio channel, the at least one detector performs the equalizing of the filtered resource elements y.

2. Method according to claim 1 , wherein the interference information indicates time/frequency location of the resource elements of the set.

3. Method according to claim 1 , wherein said receiver is served by a serving cell, and the interference information comprises information about Almost Blank Sub-frame, ABS, transmissions from one or more interfering cells.

4. Method according to claim 1 , wherein the sub-set size T is based on the channel conditions for the radio channel, is predetermined, or fixed.

5. Method according to claim 4 , wherein the channel conditions are coherence bandwidth and coherence time for the radio channel.

6. Method according to claim 5 , wherein a value for the sub-set size T is increased with increasing coherence bandwidth and coherence time; and
the value for the sub-set size T is decreased with decreasing coherence bandwidth and coherence time.

7. Method according to claim 1 , wherein the filter W is dependent on L.

8. Method according to claim 7 , wherein the filter W has the form:
W =( G *) −1 (Γ+ I ) H *( HH*+R WW ) −1 ,

where G is the virtual MIMO matrix having dimension L×L, Γ equals Γ=G*G+I, I is the identity matrix, H is the channel matrix of all T resource elements, and R WW is the covariance matrix of the interference across the T number of resource elements.

9. Method according to claim 8 , wherein (HH*|R WW ) −1 =U[Λ◯|Φ] −1 U*, where U is the left unitary matrix of the singular value decomposition of HH*, where Λ is the eigenvalues of the average channel H =Σ t=1 T H t H t *, ⊕ is the Kronecker summation operator, and Φ is a T×T covariance matrix of the interference across the T number of resource elements at one receiver antenna, Φ[m,n]=R WW [R(m−1)+1,R(n−1)+1], where R is the number of receiver antennas at said receiver.

10. Method according to claim 1 , wherein the stop of equalizing involves for m=1:M, where is the number of detectors:
taking elements (m−1)L+1:mL of the filtered resource elements y;
feeding the elements (m−1)L+1:mL to the detector.

11. Method according to claim 10 , wherein L>1.

12. Method according to claim 11 , wherein the number of detectors is M=PT/L, where P is the number of transmit antennas and T is the sub-set size.

13. Method according to claim 1 , wherein the at least one detector is a near optimum detector for the linear Gaussian vector channel.

14. Method according to any of the preceding claims, wherein said plurality of resource elements are allocated in one or more Resource Block (RB) pairs.

15. Non-transitory computer readable medium having computer executable instructions, the instructions enabling a receiver device of a cellular wireless communication system to receive radio signals, comprising:
receiving at least one radio signal comprising a plurality of resource elements;
obtaining interference information associated with the plurality of resource elements;
extracting resource elements from the plurality of resource elements carrying data into a set based on the interference information, the set including resource elements affected by interference from among resource elements of the plurality of resource elements unaffected by interference;
dividing the resource elements in the set into one or more sub-sets each comprising T number of resource elements, the one or more sub-sets being formed to correlate with interference;
filtering the resource elements in said one or more sub-sets by applying a balanced whitening and energy focusing filter W and obtaining filtered resource elements y; and
equalizing the filtered resource elements y using at least one detector configured to handle L MIMO layers in the receiver device of the cellular wireless communication system from among the plurality of resource elements including the resource elements unaffected by interference which are comprised in radio signals of different channels and pilot symbols received over a MIMO radio channel, the at least one detector performs the equalizing of the filtered resource elements y.

16. Receiver device of a cellular wireless communication system, said receiver device being arranged to receive radio signals, the receiver comprising:
a processor arranged to:
receive at least one radio signal comprising a plurality of resource elements;
obtain interference information associated with the plurality of resource elements;
extract resource elements from the plurality of resource elements carrying data into a set based on the interference information, the set including resource elements affected by interference from among resource elements of the plurality of resource elements unaffected by interference;
divide the resource elements in the set into one or more sub-sets each comprising T number of resource elements, the one or more sub-sets being formed to correlate with interference;
filter the resource elements in said one or more sub-sets by applying a balanced whitening and energy focusing filter W and obtaining filtered resource elements y; and
equalize the filtered resource elements y using at least one detector configured to handle L MIMO layers the at least one detector being in the receiver device of the cellular wireless communication system from among the plurality of resource elements including the resource elements unaffected by interference which are comprised in radio signals of different channels and pilot symbols received over a MIMO radio channel, the at least one detector performs the equalizing of the filtered resource elements.

Assignees

• Huawei Tech Co Ltd

Inventors

• Rusek Fredrik
• Priyanto Basuki Endah
• Hu Sha
• Wu Gengshi
• Kant Shashi

Classifications

• H04L25/03171

  Arrangements involving maximum a posteriori probability [MAP] detection · CPC title

• H04B7/0413

  MIMO systems · CPC title

• H04W28/048

  Electricity · mapped topic

• H04L25/03821

  Inter-carrier interference cancellation [ICI] · CPC title

• H04L27/2691

  involving interference determination or cancellation · CPC title