Invented by Sairamesh Nammi, Arunabha Ghosh, Xiaoyi Wang, Milap Majmundar, AT&T Intellectual Property I LP
The AT&T Intellectual Property I LP invention works as follows
The disclosed subject matter is a method for selecting uplink waveforms in wireless communication system, more specifically Fifth Generation (5G) wireless communications systems. In one or several embodiments, the system comprises a processor with a memory storing executable instructions which, when executed by a processor, enable performance of operations. These operations may include facilitating the establishment of a wireless connection between a device and a network device, or determining the waveform filtering protocols to be used by the device when transmitting data from the device uplink.Background for The selection of uplink waveforms for communication is made easier.
To meet the demand for data-centric applications, Third Generation Partnership Project ( 3GPP ) systems as well as systems that use one or more of the specifications for the fourth generation (4G ) standard of wireless communication will be upgraded to the fifth generation (5G ) standard. The 5G wireless networks are being developed to meet a wide range of requirements and use cases, including mobile broadband and machine type communication (MTCs). In mobile broadband, 5G networks will be able to handle the exponentially growing data traffic. They will also allow machines and people to access gigabit data speeds with almost zero latency. In comparison to 4G technologies such as advanced LTE and long-term evolution networks, 5G aims for a much higher throughput, low latency, and higher carrier frequencies, while reducing costs and energy consumption. There are unique challenges to providing levels of service that align with the upcoming 5G standards or other next-generation networks.
BRIEF DESCRIPTION DES DRAWINGS
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FIG. “FIG.3 is an illustration that illustrates an example network device which facilitates network assisted selection of waveforms for UE uplink communication in accordance with different aspects and embodiments.
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The selection of radio waveforms or modulation schemes plays an important part in the design and development of 5G wireless communications systems. This is due to the impact it has on the complexity of transceivers, radio numerology and the design of the transceiver. Waveforms for 5G wireless communications systems should meet various 5G requirements such as high spectral efficiencies (at least at sub-millimeter wave frequencies), low complexity, and low latency. Several waveforms are being researched as potential candidates for the 5G air interface, each having different advantages and drawbacks with respect to various design parameters, such as but not limited to: peak-to-average-power ratio, out-of-band leakage, bit-error-rate (BER) in multipath, complexity (at the transmitter and the receiver), multi-user support, multiple input, multiple output (MIMO) support, latency, asynchronicity, and the like. Most widely studied were the discrete Fourier Transform (DFT), spread (precoded), OFDM and Orthogonal Frequency Division Multiplexing (OFDN), also known as Single Carrier frequency Division Multiplexing (SCFDMA). OFDM and FBMC both use multicarrier techniques that transmit data simultaneously over multiple subcarriers. The pulse shaping at each subcarrier is the main difference between OFDM & FBMC. OFDM implements a square window with a time domain that is very efficient, whereas FBMC uses a pulse shaping function at each subcarrier. As an enhancement to the DFT s-OFDM, a zero-tail DFT spread waveform (ZT DFT s-OFDM), has been proposed. Generalized frequency division multiplexing waveform (GFDM) has been also considered, which uses a unique cyclic preset (CP) to reduce system overhead. The universal filtered multicarrier provides a solution that is intermediate between OFDM, FBMC and CFMC. It does this by filtering on a frequency-block basis instead of per subcarrier. Other waveform candidates include but are not limited to unique-word (UW) DFT-Spread-OFDM, UW-OFDM, CP-OFDM, resource-block-filtered OFDM, and universal filter multi-carrier (UFMC).
The selection of radio waveforms or modulations has a further impact on the numerology design. The waveform configuration is referred to as numerology. In the case of OFDM, and waveforms related to it, numerology refers primarily to waveform configurations in terms such as sub-carrier spacings, symbol durations, cyclic prefixes, resource block sizes, transmission intervals (TTIs), etc. 5G also supports a variety of waveforms. A radio numerology optimized for the system is crucial to the system design, as it allows the best use of radio resources while meeting the design requirements. The design of the radio numerology is dependent on the carrier frequency and the propagation characteristics in the environment where the system will operate.
Furthermore…with respect to waveforms and modulations that use multiple sub-bands, or sub-carriers, where data symbols are simultaneously transmitted over multiple frequency subcarriers, (e.g. OFDM, CPOFDM DFT-spread, UFMC FMBC etc.), 5G provides for different numerologies within a single waveform type. 5G allows for multiple numerologies to be used within the same waveform type. The sub-bands and sub-carriers may have different numbers. With conventional OFDM, CPOFDM and other signal modulation schemes, a unified numbering can be applied to the entire bandwidth. This means that the entire bandwidth will have the same waveform parameters (i.e. the subcarrier spacing and CP and TTI lengths). The same frequency domain filters are used to filter each sub-band, which is referred herein as wideband filters or wideband filtering schemes. In some implementations each sub-band may be filtered using the same time domain, a technique called time domain windowing. In some adaptations, sub-bands are filtered separately. Each sub-band may be configured to have different waveform parameters, or numerical values. Sub-band filtered schemes or waveform configurations where sub-bands have different numerical filters are described here.
The subject disclosure relates to computer-implemented systems, methods, devices and/or software products that enable UEs to select the radio frequency uplink signaling design. In some embodiments, waveform selection is performed by the UE network, and it can then instruct the UEs that are serviced by this network (e.g. by a node at the physical layer (PHY)) to use a certain waveform configuration depending on the current network conditions. This scenario is herein referred to as network assisted selection of waveforms. In certain additional embodiments the UEs are able to autonomously decide what waveform they want to use based on current network conditions. This scenario is referred herein to as UE based selection of waveforms. The network conditions in various embodiments can include (but not be limited to): the scheduling constraints of the node, such as the physical resource blocks (PRBs), spatial layer assignments, and so on. Current traffic conditions, such as the amount of traffic, associated load, and type of traffic that is scheduled for UEs. UEs’ relative locations, UEs’ capabilities in terms of generating different types traffic, the current signal-to-noise ratio (SNR), the current signal-to interference plus noise (SINR) of a UE and similar.
For example in accordance to network assisted waveform choice, UEs in a wireless communications network can establish respective communication links with a device network (e.g. a NodeB, an eNodeB, access point devices, etc.). Designed to facilitate wireless communication between the respective UEs. The UEs can be configured with the network device to use a multi-carrier scheme which provides wideband filtering and time domain window filters, as well as sub-band filters (e.g. OFDM, CP OFDM, DFT spread OFMD, UFMC and FMBC). The network node/device may also determine a waveform filtering system for each UE to use on uplink transmissions based upon one or more network conditions that are associated with facilitating wireless communication of the UEs. Waveform filtering schemes can be implemented in one or more implementations. They may include sub-band, wideband, and time domain window filters. The network node/device may also instruct the respective UEs on how to implement the waveform-filtering scheme that was selected for each UE. After the network device/node selects a specific waveform filtering for a UE it can send a message to the UE identifying which waveform the UE is supposed to apply. In some implementations the waveform message can be sent using just one bit on the control channel. A first bit value in a message sent over the control channel could indicate that the UE is to apply wide-band filters, and a second value could indicate sub-band filters (or vice-versa). The UE may also be configured to understand the waveform-assignment message and use the directed waveform while configuring and sending RF signals.
In some embodiments, a network node/device may dynamically direct UEs on how to filter waveforms based on the current network conditions. The network, for example, can instruct a UE on how to filter a particular waveform based upon the current network conditions. A network node/device can determine, for example, that a UE does not need to continue using a subband filtering scheme based on a drop in traffic. The network node/device, for example, may determine that a UE should stop using the sub-band scheme as directed previously and instead use a wideband scheme to minimize inference leakage into adjacent wireless systems. In these embodiments, a network device may be configured to send UE a new waveform assignment message directing UE to use the different filtering method. This updated waveform message can be sent in the control channel, or through a different signaling level.
According to UE-based waveform selection the UE may autonomously determine which waveform filtering schemes to apply to uplink communication based on one of more current network conditions. In the context of establishing a wireless link with a node in the network, for example, the UE may receive or determine information about, but not limited, scheduling information (e.g. PRB assignments), spatial layer assignments (MCS), assigned modulation, etc. Current traffic conditions are determined by the amount of traffic, associated load, and type of traffic that is scheduled for UEs. The relative location of the UE in relation to other UEs. The UE’s capabilities to generate different types of traffic. Depending on the current conditions of the network, the UE may be configured to select wideband filtering or time domain windowing filters. The UE will then configure the uplink communication according to the filtering scheme selected.
In additional embodiments,” the network or one or several network devices may dynamically determine which waveform numbering the UE should use (i.e. the waveform parameter values), based on traffic or scheduling conditions. The network or one or more devices can also send a waveform message to the UE that includes information identifying which waveform parameters are to be applied. The UE may also be configured to understand the waveform message and use the specified waveform parameters for configuring, transmitting RF signal and decoding received RF signal. In various other embodiments, where the wireless communication system uses different waveforms to facilitate communication between UEs, and network devices the network or one or more devices can determine based on current traffic conditions and/or schedules what waveform (and, in some implementations, waveform type and numbering) the UE should use. The network or one or more devices can also send a waveform message to the UE that includes information identifying which waveform type is being used (and, in some cases, the type and number). The UE may also be configured to read the waveform message and use the directed waveform (and its numerical value) for configuring RF signals, transmitting RF signal and decoding received RF signal.
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