System and Method for Increasing Low Density Signature Space

• US 20150071182A1
• Filed: 09/09/2013
• Published: 03/12/2015
• Est. Priority Date: 09/09/2013
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Bayesteh, Alireza, Ma, Jianglei, Nikopour, Hosein, Yi, Zhihang
• Granted Patent: US 9,641,303 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04W 72/00 Local resource management
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network

Abstract

Embodiments are provided herein for increasing low density signature space for multiplexed transmissions for a plurality of users. The embodiments include generating a virtual signature using a combination operation on a plurality of basic signatures. The generated virtual signatures are provisioned as basic resource units (BRUs) for transmissions for corresponding users. The combination operation is a row-wise or column-wise permutation for combining, in each of the virtual signatures, rows or columns of corresponding basic signatures. The rows or columns represent sequences of frequency bands at one time interval or sequences of allocated time intervals at one frequency band. Alternatively, the combination operation is intra-basic resource unit (BRU) hopping. The embodiments also include generating a plurality of BRU sets comprised of virtual signatures. Each of the BRU sets is provisioned for a corresponding user.

Claims

1. At a network component, a method for providing increased signature space for multiplexed transmissions for a plurality of users, the method comprising:

obtaining a set of basic signatures;

generating a set of virtual signatures using a combination operation on the basic signatures, wherein each of the virtual signatures comprises a combination of at least some of the basic signatures; and

provisioning each of the virtual signatures as a basic resource unit (BRU) for a user transmission.

2. The method of claim 1, wherein the obtaining the set of basic signatures includes generating the basic signatures using a low density signature generation method.

3. The method of claim 1, wherein the combination operation is a row-wise permutation for combining, in each of the virtual signatures, rows of corresponding basic signatures, each of the rows includes a same basic signature selected from the set of basic signatures, and wherein the rows represent sequences of frequency bands at one time interval or sequences of allocated time intervals at one frequency band.

4. The method of claim 1, wherein the combination operation is a column-wise permutation for combining, in each of the virtual signatures, columns of corresponding basic signatures, each of the columns includes a same basic signature selected from the set of basic signatures, and wherein the columns represent sequences of time intervals at one frequency band or sequences of frequency bands at one time interval.

5. The method of claim 1, wherein the combination operation is intra-BRU hopping to add, in each of the virtual signatures, a hopping sequence of basic signatures, and wherein each of the virtual signatures includes rows, columns, or both rows and columns each including a sequence of the basic signatures.

6. The method of claim 1 further comprising:

repeating the obtaining and generating steps until generating a plurality of BRUs, wherein the method further comprises;

generating a plurality of BRU sets each comprising a combination of BRUs; and

provisioning each of the BRU sets for a corresponding user.

7. The method of claim 6, wherein the BRU sets comprise a first BRU set and a second BRU set, wherein the first BRU set comprises a first combination of BRUs corresponding to a first combination of virtual signatures, and wherein the second BRU set comprises a second combination of BRUs corresponding to a second combination of virtual signatures.

8. The method of claim 7, wherein each of the BRU sets comprises a same number of BRUs, and wherein a total number of BRU sets is equal to all possible combinations of BRUs in a BRU set.

9. The method of claim 1, wherein each of the virtual signatures comprises a same number of basic signatures, and wherein a total number of virtual signatures is equal to a total number of basic signatures raised to a power of the number of basic signatures in a virtual signature.

10. The method of claim 1 further comprising generating a quantity of the virtual signatures greater than a quantity of the basic signatures and greater than or equal to a quantity of pilot signals.

11. At a network component, a method supporting low density signatures for multiplexed transmissions for a plurality of users, the method comprising:

receiving a plurality of basic resource units (BRUs) for a plurality of users, wherein the BRUs are comprised of virtual signatures, each virtual signature including a combination of low density signatures;

decorrelating the virtual signatures to narrow down a list of pilot signals, wherein a total number of configured virtual signatures exceeds a total number of available low density signatures; and

estimating channels using the list of pilot signals.

12. The method of claim 11 further comprising:

obtaining a set of active virtual signatures from the list of pilot signals, wherein the set of active virtual signatures is a subset of the virtual signatures;

processing the estimated channels using the set of active virtual signatures;

decoding data of the users according to the processed estimated channels; and

providing updated a priori probabilities for the virtual signatures and the pilot signals according to the processed estimated channels.

13. The method of claim 11 further comprising mapping the virtual signatures in a one-to-one mapping to a complete pool of available pilot signals, wherein decorrelating the virtual signatures to narrow down the list of the pilot signals includes removing a pilot signal mapped to an inactive virtual signature from the list of pilot signals upon detecting the inactive virtual signature.

14. The method of claim 11, wherein the virtual signatures comprise a first virtual signature and a second virtual signature, wherein the first virtual signature comprises a first combination of basic signatures, and wherein the second virtual signature comprises a second combination of basic signatures.

15. A network component for supporting increased signature space for multiplexed transmissions for a plurality of users, the network component comprising:

a processor; and

a computer readable storage medium storing programming for execution by the processor, the programming including instructions to;

receive a plurality of basic resource units (BRUs) for a plurality of users, wherein the BRUs are comprised of virtual signatures, each virtual signature including a combination of basic signatures;

decorrelate the virtual signatures to narrow a list of pilot signals, wherein a total quantity of configured virtual signatures exceeds a total quantity of available basic signatures; and

estimate channels using the list of pilot signals.

16. The network component of claim 15, wherein the programming includes further instructions to:

obtain a set of active virtual signatures from the list of pilot signals, wherein the set of active virtual signatures is a subset of the virtual signatures;

process the estimated channels using the set of active virtual signatures;

decode data of the users according to the processed and estimated channels; and

provide updated a priori probabilities for the virtual signatures and the pilot signals according to the processed and estimated channels.

17. The network component of claim 15, wherein the instructions to receive the plurality of BRUs includes instructions to receive the basic signatures, the basic signatures being generated using a low density signature generation method.

18. The network component of claim 15, wherein the programming further includes instructions to:

map the virtual signatures in a one-to-one mapping to a pool of available pilot signals,

wherein the instructions to decorrelate the virtual signatures to narrow the list of the pilot signals includes instructions to remove a pilot signal mapped to an inactive virtual signature from the list of pilot signals upon detecting the inactive virtual signature.

19. The network component of claim 15, wherein the programming further includes instructions to receive a plurality of BRU sets for the users, each BRU set comprising a combination of BRUs.

20. The network component of claim 19, wherein the BRU sets comprise a first BRU set and a second BRU set, wherein the first BRU set comprises a first combination of BRUs corresponding to a first combination of virtual signatures, and wherein the second BRU set comprises a second combination of BRUs corresponding to a second combination of virtual signatures.

21. The network component of claim 15, wherein each of the virtual signatures comprises a same number of basic signatures, and wherein a total number of virtual signatures is equal to a total number of basic signatures raised to a power of the number of basic signatures in a virtual signature.