WO2018010776A1

WO2018010776A1 - Systems and methods for estimation of wireless channels estimation error parameters

Info

Publication number: WO2018010776A1
Application number: PCT/EP2016/066573
Authority: WO
Inventors: Jesus ARNAU YANEZ; Marios Kountouris; Jianqiang Yang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2016-07-13
Filing date: 2016-07-13
Publication date: 2018-01-18

Abstract

There is provided a user equipment (UE) apparatus adapted to communicate over a network supported by a plurality of base stations, comprising: a processor adapted to: calculate a wireless channel estimation based on an analysis of at least one pilot sequence intercepted from at least one transmission of at least one of a plurality of base stations of a network; use the wireless channel estimation for obtaining at least one channel estimation error parameter of a channel estimation error; and instruct a transmitter to transmit the at least one channel estimation error parameter to the at least one base station.

Description

SYSTEMS AND METHODS FOR ESTIMATION OF WIRELESS CHANNELS

ESTIMATION ERROR PARAMETERS

BACKGROUND

The present invention, in some embodiments thereof, relates to wireless networks and, more specifically, but not exclusively, to systems and methods for estimation of wireless channel mismatch of a wireless communication network.

Wireless communication systems, in which a base station (BS) communicates with one or more user equipment (UE), control signal transmission and/or reception over the wireless channel based on the response of the wireless channel, also termed channel state information (CSI). In standard systems, the UE estimates the CSI, and uses the estimated CSI in the signal reception process. The UE sends some information about the CSI to the BS for control of the next transmission.

However, with introduction of new architectures with a larger number of antennas at each BS supporting a larger number of UE, the CSI information may not be accurate enough to adapt the transmitting antennas of the BS to provide the desired capacity.

SUMMARY

It is an object of the present invention to provide a user equipment, a base station, a system, a computer program product, and a method for communicating over a network.

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

According to a first aspect, a user equipment (UE) apparatus adapted to communicate over a network supported by a plurality of base stations, comprises: a processor adapted to: calculate a wireless channel estimation based on an analysis of at least one pilot sequence intercepted from at least one transmission of at least one of a plurality of base stations of a network; use the wireless channel estimation for obtaining at least one channel estimation error parameter of a channel estimation error; and instruct a transmitter to transmit the at least one channel estimation error parameter to the at least one base station.

The channel estimation error parameter(s) is calculated by the UE (rather than by the base station), which improves utilization of the wireless channel and/or improves computational efficiency of the system and/or base station, by preventing or reducing feedback of past channel estimation from the UE to the base station. Methods that feedback the past channel estimation from the UE to the base station do not scale effectively for use in current or foreseen communication standards, for example, standards based on multiple antennas at each base station to serve a large number of UE.

Moreover, performing the computations to obtain the channel estimation error parameter(s) at the UE, rather than sending the data to the base station to perform the computation, reduces traffic over the wireless channel, which efficiently improves utilization of the channel. In addition, in a system with multiple UEs, each UE may calculate its respective channel estimation error parameter(s), rather than the base station centrally performing the calculation(s), which improves computational efficiency of the base station, by reducing processing resource requirements, reducing processing time, and/or improving memory utilization (by reducing memory storage requirements).

The channel estimation error parameter is calculated based on the pilot sequence(s), without necessarily using a parametric model of the channel estimation process, which improves accuracy of the channel estimation error parameter. Obtaining the channel estimation error parameter from the calculated wireless channel estimation, rather than using a model, improves accuracy of the channel estimation error parameter in dynamically changing environments (which cannot be successfully estimated by the model), and/or removes the reliance of unknown model parameters.

In a first possible implementation of the UE apparatus according to the first aspect, the at least one channel estimation error parameter comprises a power of the channel estimation error.

In a second possible implementation of the UE apparatus according to the first aspect, the at least one channel estimation error parameter comprises a covariance of the channel estimation error.

In a third possible implementation form of the UE apparatus according to the first aspect as such or according to any of the preceding implementation forms of the first aspect, the processor is adapted to repeat iteratively the stages of the calculate a wireless channel estimation and the wireless channel estimation for accumulating a plurality of samples of the channel estimation error and to calculate therefrom a total error power; wherein the at least one channel estimation error parameter is calculated according to the total error power. In a fourth possible implementation form of the UE apparatus according to the first aspect as such or according to any of the preceding implementation forms of the first aspect, the at least one channel estimation error parameter is encoded in an analog signal.

In a fifth possible implementation form of the UE apparatus according to the first aspect as such or according to any of the preceding implementation forms of the first aspect, the at least one channel estimation error parameter is encoded in a digital signal.

In a sixth possible implementation form of the UE apparatus according to the first aspect as such or according to any of the preceding implementation forms of the first aspect, the processor is adapted to modify an internally-computed channel quality indicator (CQI) based on the at least one channel estimation error parameter.

The channel estimation error parameter(s) calculated by the UE may be locally used by the UE to modify the internally-computed CQI. The modified CQIs, which may be transmitted to the base station, may be used to further improve the efficiency of the wireless channel, and/or improve computational efficiency of the base station (since the computations are performed by the UE), by providing a more accurate real-time indication of the quality of the wireless channel.

In a seventh possible implementation form of the UE apparatus according to the first aspect as such or according to any of the preceding implementation forms of the first aspect, the at least one channel estimation error parameter is transmitted by a single antenna of the UE apparatus to a single antenna of a plurality of antennas of the at least one base station.

In an eighth possible implementation form of the UE apparatus according to the first aspect as such or according to any of the preceding implementation forms of the first aspect, the plurality of base stations are components within a massive multiple-input and multiple- output (MIMO) architecture.

According to a second aspect, a method of using a user equipment (UE) apparatus for calculating at least one channel estimation error parameter for adjusting one or more transmission parameters of a transmitter of a base station for reducing an effect of a channel estimation error on transmissions, comprises: calculating a wireless channel estimation based on an analysis of at least one pilot sequence intercepted from at least one transmission of at least one of a plurality of base stations of a network at a UE apparatus; using the wireless channel estimation for obtaining at least one channel estimation error parameter of a channel estimation error; and instructing a transmitter of the UE apparatus to transmit the at least one channel estimation error parameter to the at least one base station for adjusting the one or more transmission parameters. According to a third aspect, a base station (BS) for connecting a plurality of user equipment apparatuses to a network, comprises: a transmitter; a processor adapted to: transmit a pilot sequence using the transmitter; extract at least one channel estimation error parameter from a wireless transmission of a user equipment (UE) apparatus that respond to an interception of the pilot sequence; compute an adjustment to at least one transmission parameter of the transmitter for reducing an effect of a channel estimation error on transmissions of the transmitter; instruct applying the adjustment on transmissions from the transmitter.

In a first possible implementation of the BS according to the third aspect, the at least one transmission parameter is selected from the group consisting of: a precoding matrix, a modulation and coding scheme (MCS), and a power allocation scheme.

In a second possible implementation form of the BS according to the third aspect as such or according to any of the preceding implementation forms of the first aspect, the adjustment to at least one transmission parameter of the transmitter for reducing the effect of the channel estimation error is selected from the group consisting of: improved power allocation, robust precoding, improved user equipment scheduling, and refining pilot sequence length selection.

According to a fourth aspect, a method of using a base station (BS) for adjusting one or more transmission parameters of a transmitter of a base station for reducing an effect of a channel estimation error on transmissions, comprises: transmitting a pilot sequence using the transmitter; extracting at least one channel estimation error parameter from a wireless transmission of a user equipment (UE) apparatus that respond to an interception of the pilot sequence; computing an adjustment to at least one transmission parameter of transmitter for reducing an effect of a channel estimation error on transmissions of the transmitter; instructing applying the adjustment on transmissions from the transmitter.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1 is a block diagram of components of a wireless communication system that includes user equipment that calculates channel estimation error parameters for use by base station(s) to adjust transmission parameter(s), in accordance with some embodiments of the present invention;

FIG. 2 is a dataflow diagram depicting transmission of data between base station and user equipment for calculating and applying the channel estimation error parameter(s), in accordance with some embodiments of the present invention;

FIG. 3 is a flowchart of a method of using user equipment for calculating channel estimation error parameter(s) for adjusting transmission parameter(s) of a transmitter of a base station for reducing an effect of a channel estimation error on transmissions, in accordance with some embodiments of the present invention;

FIG. 4 is a flowchart of a method of using a base station for adjusting transmission parameter(s) of a transmitter of the base station for reducing an effect of a channel estimation error on transmissions, in accordance with some embodiments of the present invention; and

FIG. 5 is a flowchart depicting an exemplary algorithm to estimate the channel mismatch power parameter (i.e., of the channel estimation error parameter), in accordance with some embodiments of the present invention.

DETAILED DESCRIPTION

An aspect of some embodiments of the present invention relates to user equipment (UE) of a wireless communication network and/or method of operating the UE, that calculates channel estimation error parameter(s) and transmits the channel estimation error parameter(s) to one or more base stations of the wireless communication network. The channel estimation error parameter(s) are for a channel estimation error of a wireless channel estimation. The channel estimation error may also be referred to herein as the channel mismatch, which represents the error between the actual channel response, and the wireless channel estimation. The wireless channel estimation, accounting for the channel estimation error is a more accurate representation and/or value of the CSI (e.g., as measured by other systems). The UE calculates the wireless channel estimation based on an analysis of pilot sequence(s) intercepted from a transmission(s) of one or more of the base stations. The UE obtains the channel estimation error parameter(s) of a channel estimation error using the wireless channel estimation. The base station(s) use the channel estimation error parameter(s) to compute and apply an adjustment to transmission parameter(s) to reduce an effect of the channel estimation error on transmissions of the transmitter of the respective base station.

The channel estimation error parameter is calculated based on the pilot sequence(s), without necessarily using a parametric model of the channel estimation process, which improves accuracy of the channel estimation error parameter. Obtaining the channel estimation error parameter from the calculated wireless channel estimation, rather than using a model, improves accuracy of the channel estimation error parameter in dynamically changing environments (which cannot be successfully estimated by the model), and/or removes the reliance of unknown model parameters. As used herein, the term channel mismatch and channel estimation error may sometimes be interchanged.

It is noted that in comparison, other systems and methods simply ignore the channel estimation error (e.g., acting as if the estimated channel is perfect), which reduces the ability to efficiently utilize the additional capacity of the wireless channel.

In yet another comparison example, some other systems use a detailed model of the estimation process to infer the channel mismatch parameters from the parameters of the system, for example, based on the training sequence length, the signal reception power, the speed of movement of the UE, and other parameters. However, such models may not accurately reflect the real time state of the channel, which reduces the ability to efficiently utilize the wireless channel.

Optionally, the channel estimation error parameter(s) include a power of the channel estimation error. Alternatively or additionally, the channel estimation error parameter(s) include a covariance of the channel estimation error. Alternatively or additionally, the channel estimation error parameter(s) is calculated according to a total power error (an intermediate variable equal to the power of z as described herein in additional detail with reference to FIG. 5), which is calculated based on an accumulation of samples of the channel estimation error.

Optionally, the processor(s) of the UE modify an internally- computed channel quality indicator (CQI) based on the channel estimation error parameter. The channel estimation error parameter(s) calculated by the UE may be locally used by the UE to modify the internally- computed CQI. The modified CQIs, which may be transmitted to the base station, may be used to further improve the efficiency of the wireless channel, and/or improve computational efficiency of the base station (since the computations are performed by the UE), by providing a more accurate real-time indication of the quality of the wireless channel.

An aspect of some embodiments of the present invention relates to a base station (or method of operating the base station) that connects multiple UEs to a wireless communication network. The base station receives a wireless transmission from one or more UEs that respond to an interception of a pilot sequence transmitted by a transmitter of the base station. The base station extracts the channel estimation error parameters(s) from the wireless transmission received from the UE(s). The base station computes and applies an adjustment to transmission parameter(s) of the transmitter to reduce an effect of a channel estimation error on transmissions of the transmitter.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

The present invention may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing.

Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network.

The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an

Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

Reference is now made to FIG. 1 , which is a block diagram of components of a wireless communication system 100 that includes multiple base stations 102 that receive channel estimation error parameter(s) from user equipment (UE) 104, in accordance with some embodiments of the present invention. UE 104 calculates the channel estimation error parameter based on a pilot sequence(s) transmitted by one or more of base stations 102. Reference is also made to FIG. 2 which is a dataflow diagram depicting transmission of data between base station 102 and user equipment 104 for calculating and applying the channel estimation error parameter(s), in accordance with some embodiments of the present invention. The dataflow diagram described with reference to FIG. 2 may be implemented by wireless communication system 100 described with reference to FIG. 1.

Base station 102 includes a receiver and/or transmitter 106 (e.g., transceiver, i.e., antenna(s)) for receiving signals from and/or transmitting signals to multiple user equipment 104 over respective channels 108. It is noted that for clarity, one user equipment 104 using one wireless channel 108 to communicated with one base station 102 is depicted, but it is understood that multiple user equipment 104 may communicate with multiple base stations 102 over respective multiple channels 108.

System 100 may be designed based on a frequency division duplex (FDD) protocol, or other communication protocols. System 100 may be arranged according to a multiple-input- multiple-output (MIMO) architecture, optionally a massive MIMO architecture, for example, each base station 102 including at least 50, or at least 100, or at least 500, or at least 1000 antennas. The systems and/or methods described herein improve utilization of the multiple antennas within system 100, providing the ability to scale and implement for example, massive MIMO architectures.

Channel(s) 108 may be implemented according to the implemented wireless communication protocol, for example, based on orthogonal frequency division multiplexing (OFDM), single carrier frequency division multiple access (SC-FDMA), and MIMO based protocols. Receiver/transmitter 106 may be implemented as a single antenna, or multiple antennas. Channel 108 may represent communication between user equipment 104 having a single antenna 116, and a single antenna of multiple antennas of transmitter(s) 106 that supports channel 108.

Base station 102 may be implemented, for example, within a base station, a transmission tower, a radio access network, or other network device that provides wireless communication services between user equipment 104 and a network 150. Exemplary networks 150 include one or more of, the internet, a private network, a wireless cellular network, and a landline telephone network. Base station 102 includes a network interface 152 for communicating with network 150.

Base station 102 may be implemented for example, as a standalone computer, as a server, as a distributed system, as software installed on an existing device (e.g., base station equipment) and/or as a hardware card or other component attached or inserted into the existing equipment.

Base station 102 includes a processing unit 110 (e.g., central processing unit(s), digital signal processing unit(s), field programmable gate array(s), customized circuit(s), processors for interfacing with other units, and/or specialized hardware accelerators (e.g., encoders, decoders, and cryptography co-processors)) which implement code stored in a memory 112 (and/or other local and/or external and/or remote storage device, e.g., hard drive, random access memory, optical drive, other storage devices).

Base station 102 includes or is in communication with a data repository 114 that stores data, for example, a random access memory (RAM), read-only memory (ROM), and/or a storage device, for example, non- volatile memory, magnetic media, semiconductor memory devices, hard drive, removable storage, optical media (e.g., DVD, CD-ROM), a remote storage server, and a computing cloud.

Data repository 114 may store adjustment code 114A (e.g., as code instructions for execution by processing unit 110) that compute an adjustment to transmission parameter(s) of transmitter(s) 106 to reduce an effect of the channel estimation error (received from user equipment 104) on transmissions of transmitter(s) 106, as described herein. User equipment 104 may be stationary device(s) and/or mobile device(s) that include a receiver and/or transmitter 116 (i.e., antenna(s)) for communication with receiver and/or transmitter 106 of base station 102. Receiver and/or transmitter 116 may be implemented using a single antenna or multiple antennas. Receiver and/or transmitter 116 may be integrated within user equipment 104 (e.g., within a mobile device) or may be an external device that can be attached and detached (or connected and disconnected) from user equipment 104, for example, a wireless modem, and a wireless connection stick. Exemplary user equipment 104 include: a computer, a server, a laptop, a mobile device, a Smartphone, a Tablet, a wearable computer, a watch computer, and a glasses computer.

Each user equipment 104 and/or base station 102 may include or be in communication with a user interface 1 18 that allows a user to enter data and/or display (and/or hear) data, for example, one or more of: a touch-screen, a display, a radiology monitor, a keyboard, a mouse, voice activated software, and a microphone.

Each user equipment 104 includes a processing unit 120 (e.g., one or more central processing units), a memory 122 that stores program code for execution by processing unit 120, and a data repository 124 that stores data including channel estimation error code 124A (instructions executable by processing unit 120) that calculate a wireless channel estimation based on an analysis of pilot sequences intercepted from base station 102, uses the wireless channel estimation to obtain channel estimation error parameter(s) of a channel estimation error, and transmits the channel estimation error parameter(s) to base station 102.

Referring now back to FIG. 2, at 202, base station 102 transmits one or more pilot sequences using transmitter 106.

At 204, user equipment 104 intercepts one or more of the pilot sequences. User equipment 104 calculates a wireless channel estimation based on an analysis of the intercepted pilot sequence(s). User equipment 104 uses the wireless channel estimation to obtain channel estimation error parameter(s) of a channel estimation error.

At 206, user equipment 104 instructs transmitter 116 to transmit the channel estimation error parameter(s) to base station 102.

At 208, base station 102 extracts channel estimation error parameter(s) from the received wireless transmission (of user equipment 104). Base station 102 computes an adjustment to transmission parameter(s) of transmitter 106 to reduce an effect of the channel estimation error on transmissions of transmitter 106. Base station 102 instructs applying the adjustment on transmissions from transmitter 106. Dataflow 202-208 are performed iteratively, and dynamically as user terminal 104 communicates with base station 102 over channel 108, providing dynamic adjustment of the transmission parameters of transmitter 106 of base station 102.

Reference is now made to FIG. 3, which is a flowchart of a method of using user equipment for calculating channel estimation error parameter(s) for adjusting transmission parameter(s) of a transmitter of a base station for reducing an effect of a channel estimation error on transmissions, in accordance with some embodiments of the present invention. The method described with reference to FIG. 3 may be implemented by wireless communication system 100 described with reference to FIG. 1. The method described with reference to FIG. 3 may represent dataflow 204 and 206 described with reference to dataflow diagram of FIG. 2.

One or more of the acts of the method described with reference to FIG. 3 may be implemented by channel estimation error code 124A, which may be stored in data repository 124 and/or memory 122, executable by processor(s) 120.

In terms of mathematical representation, the process of wireless channel estimation (e.g., estimation of the CSI) includes an error, which may be mathematically represented as h = h + e , where:

h denotes the channel response between a transmitter antenna (i.e., of the base station) and a receiver antenna (i.e., of the user equipment), at a certain time (instant in time, or interval) and at a certain frequency;

h denotes the wireless channel estimation (e.g., estimation of a channel coefficient) at the receiver end, i.e., the user terminal;

e denotes an unknown random additive error, also referred to herein as channel estimation error (which is associated with one or more channel estimation error parameters), or channel mismatch.

At 302, wireless channel estimation h is calculated based on an analysis of the pilot sequence(s) intercepted from transmission(s) of base station(s) 102. The pilot sequence is a known pilot sequence (mathematically represented herein as x), known to both base station 102 and user equipment 104.

At 304, the wireless channel estimation is used to obtain parameters of a channel estimation error.

Optionally, the channel estimation error parameter(s) include a power of the channel estimation error. Alternatively or additionally, the channel estimation error parameter(s) include a covariance (e.g., covariance matrix) of the channel estimation error. Optionally, an intermediate variable (mathematically represented herein as z) is calculated based on pilot sequence x and wireless channel estimation A . The intermediate variable z is used to estimate the power of the channel estimation error. Intermediate variable z is random. The power of z is related to the power of the channel estimation error (i.e., the power of the channel mismatch).

At 306, the stages of calculating the wireless channel estimation (block 302) and the wireless channel estimation (304) are iteratively repeated to accumulate multiple samples of the channel estimation error. The multiple samples are used to calculate a total error power, which is an intermediate variable equal to the power of z. The channel estimation error parameter(s) may be calculated using the total error power intermediate variable.

In terms of mathematical representation, up to L samples of z may be accumulated, where L denotes a pre-defined parameter. The estimation of the total power error, mathematically represented as σ^², equals the noise power (mathematically represented as σ_η ² ) plus the channel estimation error (i.e. channel mismatch) power (mathematically represented as cr_e ² ) times the number of antennas at the base station, (mathematically represented as N_T ).

A subtraction and normalization operation provides the channel estimation error power (i.e., the channel mismatch power).

Reference is now made to FIG. 5, which is a flowchart depicting an exemplary algorithm to estimate the channel mismatch power parameter (i.e., of the channel estimation error parameter), in accordance with some embodiments of the present invention. The exemplary algorithm may be implemented by channel estimation error code 124A executed by processor(s) 120 of user equipment 104.

Referring now back to FIG. 3, at 308, a transmitter 116 of UE 104 is instructed to transmit the channel estimation error parameter(s) to the base station(s) 102 for adjusting the transmission parameter(s).

Optionally, the channel estimation error parameter is encoded in an analog signal. Alternatively or additionally, the channel estimation error parameter is encoded in a digital signal.

Optionally, at 310, an internally-computed channel quality indicator (CQI) of user equipment 104 is modified based on the channel estimation error parameter(s). The CQI being modified may be defined according to a relevant communication standard being implemented within system 100. Reference is now made to FIG. 4, which is a flowchart of a method of using a base station for adjusting transmission parameter(s) of a transmitter of the base station for reducing an effect of a channel estimation error on transmissions, in accordance with some embodiments of the present invention. The method described with reference to FIG. 4 may be implemented by wireless communication system 100 described with reference to FIG. 1. The method described with reference to FIG. 4 may represent elements 202 and 208 described with reference to dataflow diagram of FIG. 2.

One or more of the acts of the method described with reference to FIG. 4 may be implemented by adjustment code 114A, which may be stored in data repository 114 and/or memory 112, executable by processing unit(s) 110.

At 402, pilot sequence(s) are transmitted using transmitter 106 of base station 102.

At 404, channel estimation error parameter(s) are extracted from a wireless transmission of user equipment 104 that responds to an interception of the pilot sequence.

At 406, an adjustment to transmission parameter(s) of transmitter 106 is computed for reducing an effect of the channel estimation error on transmissions of transmitter 106.

The adjustment to the transmission parameter(s) for reducing the effect of the channel estimation error may include one or more of: improved power allocation, robust precoding, improved user equipment 104 scheduling, and refining pilot sequence length selection.

The transmission parameters being adapted include one or more of: a precoding matrix, a modulation and coding scheme (MCS), and a power allocation scheme.

At 408, the adjustment is applied on transmissions from transmitter 106.

The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

It is expected that during the life of a patent maturing from this application many relevant base stations, transmitters, and user equipment will be developed and the scope of the terms base station, transmitter, and user equipment are intended to include all such new technologies a priori. As used herein the term "about" refers to ± 10 %.

The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to". This term encompasses the terms "consisting of and "consisting essentially of.

The phrase "consisting essentially of means that the composition or method may include additional ingredients and/or steps, but only if the additional ingredients and/or steps do not materially alter the basic and novel characteristics of the claimed composition or method.

As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

The word "exemplary" is used herein to mean "serving as an example, instance or illustration". Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

The word "optionally" is used herein to mean "is provided in some embodiments and not provided in other embodiments". Any particular embodiment of the invention may include a plurality of "optional" features unless such features conflict.

Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging/ranges between" a first indicate number and a second indicate number and "ranging/ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

WHAT IS CLAIMED IS:

1. A user equipment (UE) apparatus adapted to communicate over a network supported by a plurality of base stations, comprising:

a processor adapted to:

calculate a wireless channel estimation based on an analysis of at least one pilot sequence intercepted from at least one transmission of at least one of a plurality of base stations of a network;

use the wireless channel estimation for obtaining at least one channel estimation error parameter of a channel estimation error; and

instruct a transmitter to transmit the at least one channel estimation error parameter to the at least one base station.

2. The UE apparatus of claim 1, wherein the at least one channel estimation error parameter comprises a power of the channel estimation error.

3. The UE apparatus of claim 1, wherein the at least one channel estimation error parameter comprises a covariance of the channel estimation error.

4. The UE apparatus of any of the previous claims, wherein the processor is adapted to repeat iteratively the stages of the calculate a wireless channel estimation and the wireless channel estimation for accumulating a plurality of samples of the channel estimation error and to calculate therefrom a total error power; wherein the at least one channel estimation error parameter is calculated according to the total error power.

5. The UE apparatus of any of the previous claims, wherein the at least one channel estimation error parameter is encoded in an analog signal.

6. The UE apparatus of any of the previous claims, wherein the at least one channel estimation error parameter is encoded in a digital signal.

7. The UE apparatus of any of the previous claims, wherein the processor is adapted to modify an internally-computed channel quality indicator (CQI) based on the at least one channel estimation error parameter.

8. The UE apparatus of any of the previous claims, wherein the at least one channel estimation error parameter is transmitted by a single antenna of the UE apparatus to a single antenna of a plurality of antennas of the at least one base station.

9. The UE apparatus of any of the previous claims, wherein the plurality of base stations are components within a massive multiple-input and multiple-output (MIMO) architecture.

10. A method of using a user equipment (UE) apparatus for calculating at least one channel estimation error parameter for adjusting one or more transmission parameters of a transmitter of a base station for reducing an effect of a channel estimation error on transmissions, comprising:

calculating a wireless channel estimation based on an analysis of at least one pilot sequence intercepted from at least one transmission of at least one of a plurality of base stations of a network at a UE apparatus;

using the wireless channel estimation for obtaining at least one channel estimation error parameter of a channel estimation error; and

instructing a transmitter of the UE apparatus to transmit the at least one channel estimation error parameter to the at least one base station for adjusting the one or more transmission parameters.

11. A base station (BS) for connecting a plurality of user equipment apparatuses to a network, comprising:

a transmitter;

a processor adapted to:

transmit a pilot sequence using the transmitter;

extract at least one channel estimation error parameter from a wireless transmission of a user equipment (UE) apparatus that respond to an interception of the pilot sequence;

compute an adjustment to at least one transmission parameter of the transmitter for reducing an effect of a channel estimation error on transmissions of the transmitter;

instruct applying the adjustment on transmissions from the transmitter.

12. The base station of claim 11 , wherein the at least one transmission parameter is selected from the group consisting of: a precoding matrix, a modulation and coding scheme (MCS), and a power allocation scheme.

13. The base station of any of the previous claims, wherein the adjustment to at least one transmission parameter of the transmitter for reducing the effect of the channel estimation error is selected from the group consisting of: improved power allocation, robust precoding, improved user equipment scheduling, and refining pilot sequence length selection.

14. A method of using a base station (BS) for adjusting one or more transmission parameters of a transmitter of a base station for reducing an effect of a channel estimation error on transmissions, comprising:

transmitting a pilot sequence using the transmitter;

extracting at least one channel estimation error parameter from a wireless transmission of a user equipment (UE) apparatus that respond to an interception of the pilot sequence;

computing an adjustment to at least one transmission parameter of transmitter for reducing an effect of a channel estimation error on transmissions of the transmitter;

instructing applying the adjustment on transmissions from the transmitter.