Method for allocating time-frequency resources in a communication system

• US 7,733,828 B2
• Filed: 01/25/2007
• Issued: 06/08/2010
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Ma, Sha, Qu, Bingyu
• Primary Examiner(s): Patel; Jayanti K
• Assistant Examiner(s): Houshmand; Hooman
• Application Number:
  US11/627,203
• Publication Number:
  US 20070153834A1
• Time in Patent Office: 1,230 Days
• Field of Search: None
• US Class Current: 370/330
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation

Abstract

A method and apparatus are described that facilitate reducing intra-cell interference and meanwhile randomizing inter-cell interference without cell planning. Segment time-frequency patterns can be obtained to form multiple different segment time-frequency pattern sets where the segment time-frequency patterns in one time-frequency pattern set are orthogonal to each other. Randomly select at least one segment time-frequency pattern set in each TTI. Within each TTI, at least one user and/or traffic channel in one cell may be randomly assigned to at least one segment time-frequency pattern of the segment time-frequency pattern set.

Claims

1. A method for allocating time-frequency resources in a communication system, applicable to wireless communication systems using Orthogonal Frequency Division Multiplexing (OFDM) technology, comprising:

configuring at least one time-frequency pattern for allocating time-frequency resources in a communication system, wherein the at least one time-frequency pattern is divided into at least one set, the time-frequency patterns in the same set are orthogonal to each other and the time-frequency patterns in different sets have at most one hit, the at least one time-frequency pattern configured for allocating time-frequency resources in a communication system comprises all elements from a time-frequency pattern cluster having the maximum number of time-frequency pattern sets and satisfies two-dimensional correlation property;

extracting segment time-frequency patterns from the time-frequency pattern by a cyclic sliding window with one width or by more than one cyclic sliding window;

forming multiple segment time-frequency pattern sets from the obtained segment time-frequency patterns, wherein the segment time-frequency patterns in the same segment time-frequency pattern set are orthogonal to each other;

randomly selecting, for each Transmission Time Interval (TTI), at least one segment time-frequency pattern set; and

allocating the segment time-frequency patterns in the selected segment time-frequency pattern set to at least one user and/or traffic channel in the TTI.

2. The method of claim 1, wherein the step of extracting segment time-frequency patterns from the time-frequency pattern by a cyclic sliding window with one width or by more than one cyclic sliding window comprises:

being given a width and a fixed location for the cyclic sliding window, traversing and extracting from, by said cyclic sliding window with the fixed location, the orthogonal time-frequency patterns in one time-frequency pattern set constructed by the at least one time-frequency pattern, to obtain multiple segment time-frequency patterns corresponding to the time-frequency pattern set;

traversing, by the same way, other time-frequency pattern sets constructed by the at least one time-frequency pattern, obtaining multiple segment time-frequency patterns corresponding to each time-frequency pattern set respectively, the multiple segment time-frequency patterns corresponding to each time-frequency pattern set are orthogonal to each other;

the step of forming multiple different segment time-frequency pattern sets according to the obtained segment time-frequency patterns comprises;

the multiple segment time-frequency patterns obtained from one time-frequency pattern set naturally forming a segment time-frequency pattern set, each formed time-frequency pattern set corresponds to a time-frequency pattern set in a one to one manner.

3. The method of claim 1, wherein, when the number of the at least one time-frequency pattern configured for allocating time-frequency resources in a communication system exceeds the number of basic frequency units used in the wireless communication system, performing an extraction with a cyclic sliding window whose width is equal to the total number of the basic frequency units.

4. The method of claim 1, wherein the at least one time-frequency pattern configured for allocating time-frequency resources in a communication system is generated by at least one sequence, the time-frequency pattern is a mapping of frequency unit indices corresponding to the order of each basic time unit, or a mapping of time unit indices corresponding to the order of each basic frequency unit.

5. The method of claim 4, wherein the basic frequency unit is a sub-carrier.

6. The method of claim 4, wherein the sequence is one of a Costas sequence, a Latin-square sequence, a modified Latin-square sequence, a linear hyperbolic sequence and a modified linear hyperbolic sequence.

7. The method of claim 4, wherein the sequence is a Costas sequence constructed from Welch.

8. The method of claim 4, wherein the sequence is a Costas sequence,

the step of extracting segment time-frequency patterns from the time-frequency pattern by a cyclic sliding window with one width or by more than one cyclic sliding window comprises:

being given a width and a fixed location for the cyclic sliding window, traversing the time-frequency patterns generated from different frequency shifts for one time shift, obtaining segment time-frequency patterns that are orthogonal to each other in one segment time-frequency pattern set;

traversing different time shifts and obtaining orthogonal segment time-frequency patterns in different segment time-frequency pattern sets;

the step of allocating the segment time-frequency patterns in the selected segment time-frequency pattern set to at least one user and/or traffic channel is implemented by selecting a value of the cyclic frequency shift;

or, the step of extracting segment time-frequency patterns from the time-frequency pattern by a cyclic sliding window with one width or multiple kinds of widths comprises;

being given a width and a fixed location for the cyclic sliding window, traversing the time-frequency patterns generated from different time shifts for one frequency shift, to obtain segment time-frequency patterns that are orthogonal to each other in one segment time-frequency pattern set;

traversing different frequency shifts and obtaining orthogonal segment time-frequency patterns in different segment time-frequency pattern sets;

the step of allocating the segment time-frequency patterns in the selected segment time-frequency pattern set to at least one user and/or traffic channel is implemented by selecting value of the cyclic time shift.

9. The method of claim 4, wherein the sequence is a Latin-square sequence, or a modified Latin-square sequence, or a Linear hyperbolic sequence or a modified Linear hyperbolic sequence;

the step of extracting segment time-frequency patterns from the time-frequency pattern by a cyclic sliding window with one width or by more than one cyclic sliding window comprises;

being given a width and a fixed location for the cyclic sliding window, traversing the time-frequency patterns generated from different multiplicative factors for one time shift, to obtain segment time-frequency patterns that are orthogonal to each other in one segment time-frequency pattern set;

traversing different time shifts and obtaining orthogonal segment time-frequency patterns in different segment time-frequency pattern sets;

the step of allocating the segment time-frequency patterns in the selected segment time-frequency pattern set to at least one user and/or traffic channel is implemented by selecting different multiplicative factors;

or, the step of extracting segment time-frequency patterns from the time-frequency pattern by a cyclic sliding window with one width or by more than one cyclic sliding window comprises;

being given a width and a fixed location for the cyclic sliding window, traversing the time-frequency patterns generated from different time shifts for one multiplicative factor, obtaining segment time-frequency patterns that are orthogonal to each other in one segment time-frequency pattern set;

traversing different multiplicative factors and obtaining orthogonal segment time-frequency patterns in different segment time-frequency pattern sets;

the step of allocating the segment time-frequency patterns in the selected segment time-frequency pattern set to at least one user and/or traffic channel is implemented by selecting different multiplicative factors.

10. The method of claim 1, wherein the cyclic sliding window extracts the time-frequency pattern in the time domain, or in the frequency domain, or in both of the time domain and the frequency domain.

11. The method of claim 1, wherein the cyclic sliding window has a fixed time and/or a fixed frequency location.

12. The method of claim 1, wherein the mode of the random selection of the at least one segment time-frequency pattern set is determined by a cell-specific multi-level pseudo-random sequence.

13. The method of claim 1, wherein the at least one segment time-frequency pattern set randomly selected in each TTI fills up the time-frequency resources within the TTI without overlap.

14. The method of claim 1, wherein the allocation of the segment time-frequency patterns in the selected segment time-frequency pattern set to at least one user and/or traffic channel is random during each TTI.

15. The method of claim 1, further comprising a process of transmitting a data flow using the allocated segment time-frequency patterns:

mapping the data flow of at least one user and/or traffic channel to the allocated segment time-frequency patterns for transmitting.

16. The method of claim 1, further comprising a process of receiving a data flow using the allocated segment time-frequency patterns:

de-mapping data of at least one user and/or traffic channel from the received data flow according to the allocated segment time-frequency patterns.

17. The method of claim 1, wherein the more than one cyclic sliding window is of the same width or different width.