Method and a system for performing virtualization of a radio access technology over orthogonal frequency-division multiple access (OFDMA) wireless networks and computer program products thereof

Patent metadata

Field	Value
Publication number	US-9742535-B2
Application number	US-201414579304-A
Country	US
Kind code	B2
Filing date	Dec 22, 2014
Priority date	Dec 23, 2013
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A method for performing virtualization of a radio access technology (RAT) over Orthogonal Frequency-Division Multiple Access (OFDMA) wireless networks is provided. The method includes splitting OFDMA time-frequency resources into non-overlapping regions including a virtualization region including a part of a spectrum and the OFDMA symbols that are reserved for virtualization of the RAT; reserving resource elements of the OFDMA time-frequency resources in the virtualization region, for insertion of downlink reference signals including complex sequences known by a receiver to perform downlink channel estimation with a specified separation between signals in time and frequency domains; inserting training or pilot signals along the OFDMA time-frequency resources of the virtualization region; and mapping complex baseband symbols corresponding to information from the RAT into the OFDMA time-frequency resources of the virtualization region.

First claim

The invention claimed is:

1. A method for performing virtualization of a radio access technology (RAT) over Orthogonal Frequency-Division Multiple Access (OFDMA) wireless networks, wherein at least one user terminal is wirelessly connected to at least one base station, both the at least one user terminal and the at least one base station supporting baseband processing required by the RAT in addition to baseband processing required for operation in the OFDMA wireless network, the method comprising:
splitting OFDMA time-frequency resources into, in uplink operation, an OFDMA region comprising part of a spectrum and OFDMA symbols reserved for operation of the OFDMA wireless network, and an uplink virtualization region comprising a remaining part of the spectrum and the OFDMA symbols, the uplink virtualization region being non-overlapping with the OFDMA region and being reserved for virtualization of the RAT; and into, in downlink operation, a common control region comprising part of a spectrum and a number of OFDMA symbols reserved for common control information that is common to the OFDMA wireless network and the RAT, a data and control region comprising part of the spectrum and a number of OFDMA symbols that are not used for common control information but are reserved for data and control information of the OFDMA wireless network, and a downlink virtualization region comprising a remaining part of the spectrum and the OFDMA symbols that are reserved for virtualization of the RAT, the common control region, the data and control region, and the downlink virtualization region being non-overlapping with each other;
reserving, in the downlink operation, resource elements of the OFDMA time-frequency resources in the downlink virtualization region, for insertion of downlink reference signals including complex sequences known by a receiver to perform downlink channel estimation by the at least one user terminal with a specified separation between signals in time and frequency domains;
inserting, in the uplink operation, training or pilot signals along the OFDMA time-frequency resources of the uplink virtualization region by mapping the training or pilot signals over time-frequency resources scheduled for a particular user according to a multiple access scheme supported by the RAT, the mapping including reserving a number of time-frequency resources for the training or pilot signals with a specified separation between signals in the time and frequency domains; and
mapping, in the downlink operation and the uplink operation, complex baseband symbols corresponding to information from the RAT into the OFDMA time-frequency resources of the downlink and uplink virtualization regions in the downlink operation and the uplink operation, respectively, by:
skipping, in the uplink operation, training or pilot signals dedicated to channel estimation in the RAT; and
skipping, in the downlink operation, OFDMA time-frequency resources reserved for insertion of downlink reference signals dedicated to channel estimation in the RAT.

2. The method of claim 1 , further comprising, in the downlink operation, prior to the mapping, applying a scrambling operation to the complex baseband symbols with a cell-specific scrambling code.

3. The method of claim 1 , wherein the mapping of the complex baseband symbols is performed by a time division multiple access scheme, a frequency division multiple access scheme, a code division multiple access scheme or a space division multiple access scheme according to the RAT.

4. The method of claim 1 , wherein the mapping of complex baseband symbols is performed from lower to higher OFDMA symbols and from lower to higher subcarriers.

5. The method of claim 1 , wherein the downlink reference signals and the uplink training or pilot signals have a separation in a time domain given by a minimum supported coherence time of a channel, and a separation in the frequency domain given by a minimum supported coherence bandwidth of the channel.

6. The method of claim 1 , comprising exploiting the OFDMA time-frequency resources of the common control region by using synchronization and basic control mechanisms of the OFDMA wireless network and the RAT.

7. The method of claim 1 , wherein said OFDMA wireless network is a Long Term Evolution (LTE) wireless network.

8. The method of claim 7 , wherein the OFDMA time-frequency resources of the common control region include a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator Channel (PCFICH), a Physical HARQ Indicator Channel (PHICH), a Cell Reference Signal (CRS), a Primary/Secondary Synchronization Signal (PSS/SSS) and a Physical Broadcast Channel (PBCH).

9. The method of claim 7 , wherein the remaining part of the spectrum of the uplink virtualization region in the uplink operation is located at one of edges of an LTE spectrum to preserve a single-carrier nature of LTE uplink operation.

10. The method of claim 1 , wherein the RAT comprises a second-generation or a third-generation cellular wireless technology including at least Global System for Mobile Communication (GSM), Universal Mobile Telecommunications Service (UMTS)/High Speed Packet Access (HSPA), Worldwide Interoperability for Microwave Access (WiMAX) or Code Division Multiple Access (CDMA) 2000.

11. The method of claim 1 , further comprising translating the mapped complex baseband symbols into RF signals to be transmitted in the downlink operation or in the uplink operation.

12. A system for performing virtualization of a radio access technology (RAT) over Orthogonal Frequency-Division Multiple Access (OFDMA) wireless networks, wherein at least one user terminal is wirelessly connected to at least one base station, both the at least one user terminal and the at least one base station supporting baseband processing required by the RAT in addition to baseband processing required for operation in the OFDMA wireless network, the system comprising a memory and a processor in conjunction with the memory configured to:
split OFDMA time-frequency resources into, in uplink operation, an OFDMA region comprising part of a spectrum and OFDMA symbols reserved for operation of the OFDMA wireless network, and an uplink virtualization region comprising a remaining part of the spectrum and the OFDMA symbols, the uplink virtualization region being non-overlapping with the OFDMA region and being reserved for virtualization of the RAT; and into, in downlink operation, a common control region comprising part of a spectrum and a number of OFDMA symbols reserved for common control information that is common to the OFDMA wireless network and the RAT, a data and control region comprising part of the spectrum and a number of OFDMA symbols that are not used for common control information but are reserved for data and control information of the OFDMA wireless network, and a downlink virtualization region comprising a remaining part of the spectrum and the OFDMA symbols that are reserved for virtualization of the RAT, the common control region, the data and control region, and the downlink virtualization region being non-overlapping with each other;
reserve, in the downlink operation, resource elements of the OFDMA time-frequency resources in the downlink virtualization region, for insertion of downlink reference signals including complex sequences known by a receiver to perform downlink channel estimation by the at least one user terminal with a specified separation between signals in time and frequency domains;
insert, in the uplink operation, training or pilot signals along the OFDMA time-frequency resources of the uplink virtualization region, by mapping the training or pilot signals over ti

Assignees

• Telefonica Sa

Inventors

• Lorca Hernando Javier

Classifications

• H04L5/0007

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

• H04L5/0005

  Time-frequency · CPC title

• H04L25/03006

  Arrangements for removing intersymbol interference · CPC title

• H04J11/00

  Orthogonal multiplex systems, {e.g. using WALSH codes}(H04J13/00 takes precedence) · CPC title

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title