Method and apparatus for managing communication operations in orthogonal frequency division multiplexing system

Patent metadata

Field	Value
Publication number	US-10911191-B2
Application number	US-201916584003-A
Country	US
Kind code	B2
Filing date	Sep 26, 2019
Priority date	Sep 27, 2018
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Accordingly, the invention provides a method and apparatus for managing communication operations in an Orthogonal Frequency Division Multiplexing (OFDM) system. Further the method includes generating, by a first OFDM apparatus (100), a signal comprising data and at least one of a Reference Signal (RS) and a message, the signal is generated by repeating the at least one of the RS and the message over a set of OFDM symbols using a resource mapper, performing an Inverse Fourier Transform operation (IFFT) according to a numerology of a first OFDM apparatus, adding a Cyclic Prefix (CP) to the data, and adding a block CP to the at least one of the repeated RS and the message. Further, the method includes transmitting, by the first OFDM apparatus (100), the signal to a second OFDM apparatus (200).

First claim

What is claimed is:

1. A method for data communication in an Orthogonal Frequency Division Multiplexing (OFDM) system, comprising;
generating, by a first OFDM apparatus ( 100 ), a signal comprising data and at least one of a Reference Signal (RS) and a message, wherein the signal is generated by:
mapping the data onto frequency resources of each OFDM symbol in a set of OFDM symbols,
performing an Inverse Fourier Transform operation (IFFT) on each of the OFDM symbol in the set of OFDM symbols,
adding a Cyclic Prefix (CP) to each of the OFDM symbol in the set of OFDM symbols,
mapping at least one of the RS and the message onto the frequency resources of the first OFDM symbol in the set of OFDM symbols,
repeating at least one of the RS and the message in remaining OFDM symbols in the set of OFDM symbols,
performing an IFFT on each of the OFDM symbol in the set of OFDM symbols, and
adding a block CP to the set of OFDM symbols;

adding, by the first OFDM apparatus ( 100 ), the data and at least one of the RS and message in a time domain; and
transmitting, by the first OFDM apparatus ( 100 ), the signal to a second OFDM apparatus ( 200 ),
wherein repeating at least one of the RS and the message in the set of OFDM symbols comprises performing one of:
repeating at least one of the RS and the message in the set of OFDM symbols when numerology at the first OFDM apparatus ( 100 ) is same as numerology at the second OFDM apparatus ( 200 )
repeating at least one of the RS and the message in the set of OFDM symbols when the numerology at the first OFDM apparatus ( 100 ) is higher than the numerology at the second OFDM apparatus ( 200 ), wherein a number of OFDM symbols in the set of OFDM symbols depends on a ratio of the numerology of the first OFDM apparatus ( 100 ) to the numerology of the second OFDM apparatus ( 200 ), and
interleaving at least one of the RS and the message in a frequency domain and repeating at least one of the RS and the message in the set of OFDM symbols when the numerology at the first OFDM apparatus ( 100 ) is lower than the numerology at the second OFDM apparatus ( 200 ), wherein the interleaving is performed based on the ratio of the numerology of the first OFDM apparatus ( 100 ) to the numerology of the second OFDM apparatus ( 200 ).

2. The method of claim 1 , wherein an IFFT size is determined based on at least one of a bandwidth and the numerology used at the first OFDM apparatus ( 100 ).

3. The method of claim 1 , wherein a block CP length is obtained by scaling a CP length of an OFDM symbol by the number of repetitions.

4. The method of claim 1 , wherein at least one of the RS and the message is spread over a predefined bandwidth, wherein the predefined bandwidth is in multiple of Resource Blocks (RBs) fully or partially span over a configured bandwidth, and wherein the RBs are allocated in a consecutive manner or a continuous manner to avoid possible contamination of reception.

5. The method of claim 1 , wherein the set of OFDM symbols is determined as a function of at least one of the numerology used at the first OFDM apparatus ( 100 ), the numerology used at the second OFDM apparatus ( 200 ), and a propagation delay.

6. The method of claim 1 , comprises adding a node identifier in a sequence used for generating the RS to identify an interference at the second OFDM apparatus ( 200 ), wherein the node identifier indicates at least one of an interfering node, a group of interfering nodes, a cell and an interference level.

7. The method of claim 6 , wherein the interference level indicates at least one of a remote interference and a cross-link interference.

8. The method of claim 6 , wherein the RS is transmitted orthogonally in at least one of a code, the frequency domain, a time domain, and a space domain across various nodes in the OFDM system, based on at least one of the node identifier and an interference level and a number of affected symbols.

9. The method of claim 8 , wherein, in the time domain, the orthogonality is achieved by one of a node transmits the RS at one-time unit while all the other nodes are receiving the RS and a node receives the RS at one instant while all other nodes are transmitting the RS.

10. The method of claim 6 , wherein the node identifier is associated with one of:
the first OFDM apparatus ( 100 ) indicating that the first OFDM apparatus ( 100 ) is facing the interference from the second OFDM apparatus ( 200 ); and
the first OFDM apparatus ( 100 ) indicating that the first OFDM apparatus ( 100 ) is a source of interference for the second OFDM apparatus ( 200 ).

11. The method of claim 7 , wherein the remote interference level, at one of the first OFDM apparatus ( 100 ) and a group of first OFDM apparatus ( 100 ), is detected when an Interference over Thermal (IOT) meets a predefined threshold, wherein the IOT is the interference level measured above a thermal noise level.

12. The method of claim 8 , wherein the number of affected symbols in a transmission is determined at least one of the first OFDM apparatus ( 100 ) from the group of first OFDM apparatus ( 100 ), based on at least one of IOT value and a signal to interference plus noise ratio (SINR).

13. The method of claim 8 , wherein the number of affected symbols determines the RS transmission from the first OFDM apparatus ( 100 ).

14. The method of claim 12 , wherein at least one of the first OFDM apparatus ( 100 ) and the second OFDM apparatus ( 200 ) is configured to transmit the RS in a measurement window comprising a set of one of symbols and slots determined by network based on at least one of the interference level, and the number of affected symbols, wherein the measurement window includes DL-to-UL transition point.

15. The method of claim 14 , wherein the RS is transmitted from at least of the first OFDM apparatus ( 100 ) and the second OFDM apparatus ( 200 ) at a beginning of the measurement window configured by the network.

16. The method of claim 14 , wherein the RS is received in at least one of the first OFDM apparatus ( 100 ) and the second OFDM apparatus ( 200 ) in the last N symbols of the measurement window configured by the network, wherein the N symbols are configured by a higher layer.

17. A method for data communication in an Orthogonal Frequency Division Multiplexing (OFDM) system, comprising;
generating, by a first OFDM apparatus ( 100 ), a signal comprising data and at least one of a Reference Signal (RS) and a message, wherein the signal is generated by:
mapping the data on to frequency resources of each OFDM symbol in a set of OFDM symbols,
mapping at least one of the RS and the message onto frequency resources of the first OFDM symbol in the set of OFDM symbols,
repeating at least one of the RS and the message in remaining OFDM symbols in the set of OFDM symbols,
applying a phase rotation to at least one of the RS and the message in each of the OFDM symbol in the set of OFDM symbols, wherein the phase rotation is a function of a symbol index and a CP length,
performing an Inverse Fourier Transform operation (IFFT) on each of the OFDM symbol in the set of OFDM symbols, and

adding a CP; and
transmitting, by the first OFDM apparatus ( 100 ), the signal to a second OFDM apparatus ( 200 ),
wherein repeating at least one of the RS and the message in the set of OFDM symbols comprises performing one of:
repeating at least one of the RS and the message in the set of OFDM symbols when the numerology at the first OFDM apparatus ( 100 ) is same as the numerology at the second OFDM apparatus ( 200 ),
repeating at least one of the R

Assignees

• Centre Of Excellence In Wireless Tech
• Indian Inst Tech Madras
• Indian Institute Of Tech Amdras

Inventors

• Masal Abhijeet Abhimanyu
• Dey Priyanka
• Kaimalettu Sunil
• Baskaran Dhivagar
• Sriharsha Paka Venkata
• Milleth Jeniston Deviraj Klutto
• Ramamurthi Bhaskar

Classifications

• H04L27/2628

  Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators (H04L27/2634 takes precedence) · CPC title

• H04J11/0056 Primary

  Inter-base station aspects · CPC title

• H04L27/2613

  Structure of the reference signals · CPC title

• H04L27/26025

  Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking (allocating sub-channels of the transmission path H04L5/003) · CPC title

• H04L5/0007 Primary

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title