Method and apparatus for user distribution to sub-bands in multiple access communications systems

Patent metadata

Field	Value
Publication number	US-11323970-B2
Application number	US-201917042464-A
Country	US
Kind code	B2
Filing date	Mar 20, 2019
Priority date	Mar 28, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A system and method for assigning users to a particular sub band in a given time slot in a NOMA system, where whichever pair of users corresponds to the smallest “candidate pair user throughput deviation value”, reflecting the aggregate of the respective difference between the average throughput across all users (K) and the known throughput of each of the two users under consideration (k1k2), and each user attributed to a sub-band other than the selected sub-band. User pairs for consideration may consider all possible pairs, or may be limited to candidate pairs satisfying together, or comprising one or both users who satisfy a criterion such as channel gain, distance to a target, throughput or a combination of some or all of these factors. The power allocated to each sub-band may be attributed by a waterfilling algorithm.

First claim

The invention claimed is:

1. A system for assigning users from a set of candidate users to one of a plurality of sub-bands (s) in a current time slot (t) in a multiple access communications system, comprising:
an assignment processor adapted to select a plurality of candidate pairs of the users, each candidate pair comprising a respective first user (k 1 ) and a respective candidate second user (k 2 ), for consideration with respect to a selected sub-band,
a power calculator adapted to perform a provisional power allocation to each sub-band with regard to each candidate pair,
a throughput calculator adapted to determine a respective candidate pair user throughput deviation value reflecting an aggregate of a respective difference between an average throughput across the set of candidate users and a known throughput of the first user (k 1 ), a known throughput of the candidate second user (k 2 ), and a known throughput of each user attributed to a sub-band other than the selected sub-band,
the assignment processor being further adapted to assign to the sub-band whichever candidate pair of users corresponds to the smallest respective candidate pair user throughput deviation value.

2. A method of selection of a first user (k 1 ) and a second user (k 2 ) among a set of candidate users for attribution to one of a plurality of sub-bands (s) in a current time slot (t) in a multiple access communications system based, comprising the steps of:
selecting a candidate pair of users comprising a said first user (k 1 ) and a respective candidate second user (k 2 ), for consideration with respect to a selected sub-band,
performing a provisional power allocation to each sub-band,
determining a candidate pair user throughput deviation value reflecting an aggregate of a respective difference between an average throughput across the set of candidate users and a known throughput of the first user (k 1 ), a known throughput of the candidate second user (k 2 ), and a known throughput of each user attributed to a sub-band other than the selected sub-band,
repeating the steps of selecting a candidate pair of users, performing a provisional power allocation, determining a candidate pair user throughput deviation value for a plurality of further candidate pair of users, and
assigning to the selected sub-band whichever candidate pair of users corresponds to the smallest respective candidate pair user throughput deviation value.

3. The method of claim 2 , wherein the power allocated to each sub-band in said provisional power allocation is attributed by a waterfilling algorithm such that the power allocated to each sub-band has regard to the channel gain of each user in each respective candidate pair, and the channel gain of any user already assigned to any sub-band in the current time slot.

4. The method of claim 2 , wherein the known throughput for each user takes account of the projected throughput for that respective user for the current time slot, in addition to the average throughput during an historical time window for that respective user.

5. The method of claim 2 , wherein the step of determining a candidate pair user throughput deviation value comprises the additional steps of:
calculating a known throughput of each user in the candidate pair, and any user already assigned to any sub-band in the current time slot,
calculating an average total throughput as an average of the respective known throughput calculated for each user in the set of candidate users,
calculating a user throughput deviation value for each user in the candidate pair, and any user already assigned to any sub-band in the current time slot, the user throughput deviation value corresponding to the difference between the respective known throughput for that user and the average total throughput value, and
combining the respective user throughput deviation values for each user in the candidate pair, and any user already assigned to any sub-band in the current time slot to obtain the candidate pair user throughput deviation value.

6. The method of claim 2 , wherein the steps of selecting a candidate pair of users, performing a provisional power allocation, and determining a candidate pair user throughput deviation value, are repeated until every possible candidate pair of users has been considered.

7. The method of claim 2 , wherein the steps of selecting a candidate pair of users, performing a provisional power allocation, and determining a candidate pair user throughput deviation value, are repeated until every possible candidate pair of users comprising a first candidate user satisfying a specified criterion has been considered.

8. The method of claim 7 , wherein said specified criterion is based on one or more of channel gain, distance to a target or throughput.

9. The method of claim 2 , wherein the steps of selecting a candidate pair of users, performing a provisional power allocation, determining a candidate pair user throughput deviation value for a plurality of further candidate pairs of users, and assigning to the sub-band whichever of the candidate pairs of users corresponds to the smallest respective candidate pair user throughput deviation value are repeated for each sub-band, until one or more users are attributed to each sub-band.

10. The method of claim 9 , wherein the step of selecting a candidate pair of users, performing a provisional power allocation, determining a candidate pair user throughput deviation value for a plurality of further candidate pairs of users, and assigning to the sub-band whichever of the candidate pairs of users corresponds to the smallest respective candidate pair user throughput deviation value for each sub-band, until one or more users are attributed to each sub-band are repeated for successive said time slots.

11. An apparatus adapted to implement the steps of claim 2 .

12. A computer program adapted to implement the steps of claim 2 .

13. A computer readable medium incorporating the computer program of claim 12 .

Assignees

• Inst Mines Telecom
• Univ Libanaise
• Univ Saint Esprit De Kaslik

Inventors

• Hojeij Marie-Rita
• Abdel Nour Charbel
• Farah Joumana
• Douillard Catherine

Classifications

• H04J99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• H04L5/0071

  Allocation based on fairness other than the proportional kind · CPC title

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title

• H04L5/003 Primary

  Arrangements for allocating sub-channels of the transmission path · CPC title

• H04L5/0075

  Allocation using proportional fairness · CPC title