WO2023052027A1

WO2023052027A1 - Methods for uplink transmission, a related wireless device and a related network node

Info

Publication number: WO2023052027A1
Application number: PCT/EP2022/074320
Authority: WO
Inventors: Erik Lennart BENGTSSON; Kun Zhao; Fredrik RUSEK; Jose Flordelis; Olof Zander
Original assignee: Sony Group Corporation; Sony Europe B.V.
Priority date: 2021-10-01
Filing date: 2022-09-01
Publication date: 2023-04-06

Abstract

A method is disclosed, performed by a wireless device, for uplink transmission. The method comprises transmitting, to a network node, a first modulation symbol. The method comprises receiving, from the network node, feedback information indicative of an estimate of the first modulation symbol. The estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node. The method comprises transmitting, to the network node, a second modulation symbol. The second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

Description

METHODS FOR UPLINK TRANSMISSION, A RELATED WIRELESS DEVICE AND A RELATED NETWORK NODE

The present disclosure pertains to the field of wireless communications. The present disclosure relates to methods for uplink transmission, a wireless device, and a network device.

BACKGROUND

In 3rd Generation Partnership Project (3GPP) Fifth Generation (5G) systems, at the cell edge, the uplink signal to noise ratio (UL SNR) is inherently low for the user equipment, UE. To combat this, 3GPP has adopted repetitions of the uplink signals (up to 32 repetitions). In some instances, the 3GPP 5G systems (such as Machine Type Communication (MTC) and/or Narrow-Band Extended Coverage (NB-EC) mode B) support up to 2048 repetitions. However, for the user equipment (such as battery-powered devices, such as low power sensors), the energy available for uplink transmission is typically constrained in order to extend the lifetime of the battery.

SUMMARY

In downlink (DL), however, the network node is usually connected to the power grid and has much larger transmit power available. Accordingly, there is a need for devices and methods for uplink communication, which may mitigate, alleviate, or address the shortcomings existing and may provide an improved uplink transmission based on feedback from the network node in DL.

Disclosed is a method, performed by a wireless device, for uplink transmission. The method comprises transmitting, to a network node, a first modulation symbol. The method comprises receiving, from the network node, feedback information indicative of an estimate of the first modulation symbol. The estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node. The method comprises transmitting, to the network node, a second modulation symbol. The second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate. Further, a wireless device is provided. The wireless device comprises memory circuitry, processor circuitry, and a wireless interface, wherein the wireless device is configured to perform any of the methods disclosed herein.

It is an advantage of the present disclosure that the uplink transmission from the wireless device can be improved, in terms of robustness to errors, spectral efficiency and power control. For example, as a code with less coding rate can be used, or just less HARQ repetitions may be needed, the spectral efficiency is improved.

Further a method, performed by a network node, is disclosed. The method comprises receiving, from a wireless device, a value indicative of a first modulation symbol. The method comprises determining an estimate of the first modulation symbol by demodulating the first modulation symbol. The method comprises transmitting, to the wireless device, feedback information indicative of the estimate of the first modulation symbol. The method comprises receiving, from the wireless device, a second modulation symbol. The second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate. The method comprises demodulating, based on the correctness parameter, the second modulation symbol.

Further, a network node is provided. The network node comprises memory circuitry, processor circuitry, and a wireless interface, wherein the network node is configured to perform any of the methods disclosed herein.

It is an advantage of the present disclosure that the uplink communication from the wireless device to the network node can be improved in terms of reception, error correction, spectral efficiency and power control.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of examples thereof with reference to the attached drawings, in which:

Fig. 1 is a diagram illustrating an example wireless communication system comprising an example network node and an example wireless device according to this disclosure, Fig. 2 is a signaling diagram illustrating an example communication between an example wireless device and an example network node according to this disclosure.

Fig. 3 is a flow-chart illustrating an example method, performed by a wireless device, for uplink transmission according to this disclosure,

Fig. 4 is a flow-chart illustrating an example method, performed by a network node of a wireless communication system according to this disclosure,

Fig. 5 is a block diagram illustrating an example wireless device according to this disclosure,

Fig. 6 is a block diagram illustrating an example network node according to this disclosure,

Fig. 7 is a diagram illustrating an example alphabet for QSPK modulation scheme according to this disclosure;

Fig. 8 is a diagram illustrating an example according to this disclosure;

Fig. 9 is a graph illustrating an example performance of the disclosed technique;

Fig. 10 is a graph illustrating an example performance of the disclosed technique;

Fig. 11 are graphs illustrating examples of power scaling parameters across repetitions according to this disclosure;

Fig. 12 are graphs illustrating examples of power scaling parameters across repetitions according to this disclosure; and

Fig. 13 are graphs illustrating examples of power scaling parameters across repetitions according to this disclosure.

DETAILED DESCRIPTION

Various examples and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated example needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described.

The figures are schematic and simplified for clarity, and they merely show details which aid understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

Fig. 1 is a diagram illustrating an example wireless communication system 1 comprising an example network node 400 and an example wireless device 300 according to this disclosure.

As discussed in detail herein, the present disclosure relates to a wireless communication system 1 comprising a cellular system, for example, a 3GPP wireless communication system. The wireless communication system 1 comprises a wireless device 300 and/or a network node 400.

A network node disclosed herein refers to a radio access network node operating in the radio access network, such as a base station, an evolved Node B, eNB, gNB in NR. In one or more examples, the RAN node is a functional unit which may be distributed in several physical units.

The wireless communication system 1 described herein may comprise one or more wireless devices 300, 300A, and/or one or more network nodes 400, such as one or more of: a base station, an eNB, a gNB and/or an access point.

A wireless device may refer to a mobile device and/or a user equipment, UE.

The wireless device 300, 300A may be configured to communicate with the network node 400 via a wireless link (or radio access link) 10, 10A.

For wireless devices at the cell edge, the UL SNR is typically low. In Coverage Enhancement of 3GPP systems, repetitions of the transmitted UL signals can be carried out. In NR, signals appear in blocks, and the smallest size of a block is termed a Physical Resource Block. Each block is assumed to be repeated N times. The present disclosure focuses, inter alia, on a single symbol within such block. Since the wireless device is at cell edge, the wireless device can use modulation schemes such as Quadrature Phase Shift Keying (QPSK), and/or other alternative modulation schemes.

In the legacy system, which is based on repetitions, the QPSK alphabet can be denoted by A₀ = {1, i, -1, —i} . It is to be noted that other versions of QPSK may be used, such as using rotation and/or scaling.

The received signal can be described by

where r_n denotes a receive symbol, a denotes a symbol drawn from A₀ that is to be communicated, β is a power scaling per repetition, w_n is complex Gaussian noise with variance N₀, and where it is assumed to have a static channel, whose amplitude has been absorbed by N₀. In one or more examples of this disclosure, it is assumed to have a static channel whose amplitude has been absorbed by N₀.

After post processing at the network node, an equivalent SNR of β N/ N₀ is achieved. Repetitions may be only beneficial via accumulating more received energy. There is no added benefit of having N repetitions rather than a single one if the same total energy is used. The present disclosure addresses this shortcoming by providing feedback information indicative of an estimate of the communication between the receiver and the transmitter.

The feedback information disclosed herein is transmitted by the network node in downlink, which does not suffer from low capacity as UL does. In other words, DL can be of high quality so that the feedback information can be seen as “free” or providing negligible overhead.

It is to be noted that when there is a finite number of redundancy versions of the coded sequence, and as soon as the same version is used again, the disclosed technique can be applied. The present disclosure may be seen as providing a larger feedback information, than for example Hybrid Automatic Repeat Request (HARQ), however the disclosed feedback information is only in DL and thereby negligible in view of the resource available in DL.

The present disclosure may be seen as boosting direct link transmissions by exploiting reverse link resources which are abundant in DL.

Simply put, the present disclosure proposes to use different configurations parameters (such as dither parameters and/or alphabets) for different repetitions. For example, what alphabet to use at repetition n depends on feedback information from the network node that arrives, error-free, after transmission of repetition n-1, but before repetition n.

Fig. 2 shows a signaling diagram 500 illustrating an example communication between an example wireless device 300 and an example network node 400 for uplink transmission according to this disclosure.

The wireless device 300 may transmit to the network node 400, control signalling 502 indicative of a feedback scheme for configuring the feedback information. For example, the control signalling may be a capability signalling, such as a capability report indicating that the wireless device 300 supports a feedback scheme, optionally which feedback scheme is supported.

The wireless device 300 may receive from the network node 400, information 504 indicative of the feedback scheme to apply at the wireless device 300. In other words, information 504 may indicate to the wireless device 300 which feedback scheme should be used by the wireless device 300.

The wireless device 300 may receive from the network node 400, control signalling 506 indicative of one or more configuration parameters of the feedback scheme.

The wireless device 300 transmits for example, to the network node 400, a first modulation symbol 508, in the form of

where a denotes a symbol drawn from an alphabet, and where β₁ acts as a power scaling parameter. This is transmission 1 of Fig. 2, and may be referred to as repetition 1. In other words, the UE can select the modulation symbol a to be transmitted from a symbol alphabet, for example BPSK and can transmit

in transmission 1 . The gNB receives and demodulates the signal to obtain an estimate â of a.

The wireless device 300 receives from the network node 400, feedback information 510 indicative of an estimate a of the first modulation symbol (which may be denoted â₁ ). The estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node 400. In other words, the gNB sends the estimate â to the UE in 510. This is assumed to be an error-free transfer.

For transmission 2 (or repetition 2), which is a repetition of the first transmission of the first modulation symbol, the wireless device 300 transmits to the network node 400, a second modulation symbol 512, for example in form of

The second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

The wireless device 300 receives from the network node 400, feedback information 514 indicative of an estimate a (which may be denoted â₂) of the second modulation symbol.

For transmission n (or repetition n), for example, the UE transmits the nth modulation symbol 516

where d_n is determined based on the feedback â (which may be denoted â_n-1) received at the UE prior to repetition n. Subsequently, d_n is referred to as a dither parameter.

For example, the network node and wireless device may have agreed upon a rule for generating d_n in advance, for example in the communication exchange 502, 504, and/or 506. Therefore, d_n is known at the network node. Furthermore, the feedback â and β _n are also known to the network node, wherefore the dither can be perfectly removed at the network node side.

A dither parameter is an example of this disclosure. Other examples include a plurality of alphabets. A dither parameter may be seen as an intentionally applied form of noise. The dither parameter may not be always the same. For example the dither parameter may be determined based on a predetermined rule. Since the dither parameter can depend on the current estimate of the transmitted symbol, it varies across repetitions. The exchange 508-516 is illustrated in Fig. 2 as applied to one resource element. The exchange 508-516 occurs in parallel to all resource elements.

For example, the network node can demodulate the received signals r₁, ... ,r_n, to obtain an estimate â of a. This is feasible, since the network node is supposed to be fully aware how d_n has been generated at the wireless device.

For example, the network node can transmit feedback information indicative of the estimate â to the wireless device. This is assumed to be an error-free transfer.

It may be appreciated that the configuration parameter such as the dither parameter can reduce the transmitted energy, which allows for a larger power scaling β _n. Furthermore, the power scaling β _n and dither terms d_n to be used, are agreed upon between the wireless device and the network node in advance. For example, the power scalings β _n may be obtained by a predetermined rule, e.g. leading to a predetermined sequence. For example, the dither parameter d_n may be obtained by a predetermined rule, such as: d_n=α_nâ_n (2) wherein α_n denotes a dither strength parameter. The dither strength parameter may be obtained based on a predetermined rule. The dither strength parameter may be seen as a dither amplitude, a dither power, and/or a dither coefficient.

The performance of the system may be advantageous by determining or selecting the appropriate configuration parameters as illustrated in one or more of Equations (2)-(15).

In the following demonstration, BPSK transmissions are considered. However, the present disclosure may apply to any modulation scheme. Let A = {-1,1} denote the BPSK alphabet. The wireless device chooses a symbol a ∈ A. The transmitted modulation symbol in repetition n is given by

where â_n is the estimate of the modulation symbol (such as an estimate symbol index) by the network node based on receiving modulation symbols at repetitions 1...(n-1 ) which are sent to the wireless device prior to transmission of repetition n, where β _n and α_n are two configuration parameters that may be selected and/or determined for optimization.

In repetition 1 , there is no feedback from the network node, and therefore α₁ = 0. The term α_nâ_n acts as a dither parameter to the alphabet in repetition n, and its purpose is to reduce the transmit power. The parameters β _n act as power scalings. The dither strength parameter α_n and power scaling parameters may be agreed between the wireless device and the network node, such as via control signalling.

Now, for n > 1, with probability p_n to have that â_n ≠ a (such as probability of error), so that expected value of the transmitted signal s_n knowing the estimate â_n is expressed as

As it is a pure power loss to transmit a DC component, the dither strength parameter α_nis selected so that E(s_n| â_n) = 0, which leads to a predetermined rule e.g.: α_n = 2p_n - 1; (5)

The dither strength parameter is non-positive. It is to be noted that α₁ = 0 implies p₁ = 1/2. The Bit Error Rate, BER, of the system may be expressed simply as p_N+1.

The transmitted energy in repetition n may be expressed as e.g.:

As the dither parameter, α_n â_n, can be known at the network node, the dither parameter may be removed. Therefore, the SNR at repetition n is simply β_n/N₀, and the variables β _n can be interpreted as the receiver side signal power. As the signaling is antipodal, it follows that e.g.:

where Q( ) is the complementary error-function. Since the BER after all repetitions, i.e., p_N+1, is fully determined by β ₁ + β ₂ +...+ β _N, it follows that the quantity under constraints of the energies E_n are to be maximized. It may be judicious to let energies E_n be constrained by a sum-energy constraint across all N repetitions, which leads to solving e.g.:

where P is a constant for total transmit energy per bit or total transmit power per bit

Invoking the expression for E_n yields to e.g.:

It may be appreciated that P1 may be simple to solve using a standard computer optimization.

In one or more examples, an alternative constraint may be to constraint the average energy per repetition to be equal across all repetitions, e.g., E_n = P/N,∀n.

For example, with such constraint, no optimization is needed. For example, in repetition 1 , there is no dither, and E₁ = β ₁ = P/N. For example, this is also supported when inputting p₁ = 0.5 into E₁ = 4β ₁ p₁(1 - p₁). For subsequent repetitions n>1, p_n can be calculated from the previously determined values β ₁ ,β ₂ ..,β_n-1 as e.g.:

In one or more examples, β _ncan be calculated as e.g.:

It can be demonstrated analytically that also the constraints E_n = P/N,∀ n provide gains over the non-dithered technique. For example, for two repetitions, N=2, a gain is achieved. Using the Equations (11 ) and (12) for calculating p₃ gives, with P=2, the following:

The non-dithered technique with N=2, on the other hand, may have an error rate as e.g.:

It may be noted that the expression for any value of N₀. It may be

noted that as N₀ grows larger, the expression converges to 4 from above. This leads to

In one or more example, a constraint may be a maximum energy Ê_n per repetition that cannot be exceeded, which leads to e.g.:

For example, P2 may be solved simply. For example it can be shown that by setting Ê_n = P/N, P2 reduces to the uniform power problem as shown under (10). Similarly, for example, by setting Ê_n = ∞ , ∀n, P2 reduces to P1.

Fig. 3 shows a flow diagram of an example method 100, performed by a wireless device according to the disclosure, for uplink transmission. The method 100 may be performed by wireless device disclosed herein, such as the wireless device 300 of Fig. 1 , and Fig. 5.

The method 100 comprises transmitting S104, to a network node, a first modulation symbol. For example the first modulation symbol may be obtained by applying a modulation scheme, for example selecting a symbol in an alphabet of a modulation scheme. Examples of modulation schemes include one or more of: BPSK, QPSK, M- Quadrature Amplitude Modulation, M-ary single-dimensional modulation where M is a positive integer. The first modulation symbol may be seen as modulation symbol a in Equation (1 ).

The method 100 comprises receiving S106, from the network node, feedback information indicative of an estimate of the first modulation symbol. In one or more example methods, the estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node. In one or more example methods, the estimate is obtained by receiving and demodulating the first modulation symbol at the network node. In other words, the network node can receive and may demodulate (such as using hard demodulation and/or soft demodulation) the first modulation symbol and can then generate an estimate of the received first modulation symbol. For example, the network node receives , and demodulates the signal to obtain an estimate â of a.

The feedback information may be indicative of an estimate â of a. In other words, for example, the estimate is indicative of the modulation signal as it appeared, or was interpreted, when it was received by the network node. In other words, for example, the estimate is indicative of the modulation signal after propagating over a channel between the wireless device and the network node. The method 100 comprises transmitting S108, to the network node, a second modulation symbol wherein the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate. The correctness parameter may be seen as a parameter that is configured to quantify and/or qualify an error characteristic based on the received modulation symbol. In one or more example methods, the correctness parameter is indicative of an error characteristic, such as error rate, of the estimate. For example, the correctness parameter is used, e.g., to select from a discrete set of elements (e.g. a value of the dither strength parameter and/or a value of the power scaling parameter).

In other words, for example, the wireless device transmits the first modulation symbol, receives feedback information indicative of the estimate (for example indicating how the first modulation symbol was estimated at the network node), and transmits the second modulation symbol with adaptation based on the correctness of the estimate.

In one or more example methods, the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by applying, to the first modulation symbol, one or more configuration parameters associated with the feedback information.

In one or more example methods, the one or more configuration parameters are based on one or more predetermined rules. In other words, the wireless device and the network node may have agreed, e.g. via signalling, on the predetermined rules to apply, so as to obtain the configuration parameters to apply in the repetitions.

In one or more example methods, the method comprises obtaining the one or more predetermined rules. For example, Equations (2)(4)(5) are examples of predetermined rules. In one or more example methods, the one or more predetermined rules comprise one or more of: a set of dither strength parameters, a predetermined mapping, a predetermined rule based on a correctness parameter of the estimate, such as a quality of the estimate (probability that estimate fed back is correct), a predetermined set, predetermined values, like a codebook for optimum values of the dither strength parameter and/or of the power scaling parameter, such as 10 values for the dither strength parameter, and 10 for the power scaling parameter.

In one or more example methods, the one or more configuration parameters comprise information indicative of one or more of: a dither parameter, a power scaling parameter, a plurality of alphabets.

In one or more example methods, the dither parameter is based on the estimate and a dither strength parameter. For example, the dither strength parameter may be seen as a coefficient or a factor controlling how to apply the estimate. For example, the dither strength parameter may be a set of α_n values. For example, α_n can be based on the quality or correctness of the estimate and/or feedback information. In other words, α_n can be based on based on how correct a is, which may be based on SNR.

For example, an instantaneous transmit power can be selected from a discrete set of allowable transmit powers, e.g. β_n ∈ B = {b₀, ... , b_M}.. For example, the values b₀, ... , b_M can correspond to -3 dBm, 0 dBm, 3 dBm,..., 12 dBm.

In one or more example methods, the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by selecting, based on the estimate, an alphabet amongst the plurality of alphabets. In one or more example methods, the alphabet comprises an ordered set of modulation symbols. This is illustrated in Fig. 7.

In one or more example methods, the method 100 comprises transmitting S102, to the network node, control signalling indicative of a feedback scheme for configuring the feedback information. In one or more example methods, the control signalling may inform of a flag that is set in a control message.

In one or more example methods, the control signalling comprises capability signalling indicative of the feedback scheme. In one or more example methods, the capability signalling may indicate a release number and/or an index of a look up table where the configuration parameter(s) is stored.

In one or more example methods, the method 100 comprises receiving S103, from the network node, information indicative of the feedback scheme to apply at the wireless device. This is illustrated for example in Fig. 2. In one or more example methods, the control signalling comprises a request for activating a feedback scheme. In one or more example methods, the method comprises receiving, from the network node, a response.

In one or more example methods, the control signalling is indicative of the one or more configuration parameters of the feedback scheme. This is illustrated for example in Fig. 2.

In one or more examples where a higher order modulation scheme is used, such as M-ary single-dimensional constellations are considered. For example using 4-Pulse Ampltiude Modulation, 4-PAM, but it should be clear to the person skilled in the art how to transfer this to a general M-ary constellation. For example, a 4-PAM alphabet is considered with A = {-3, -1,1,3}. The wireless device selects one modulation symbol a ∈ A, transmits the symbol and prior to each repetition n, the wireless device receives feedback information indicative of the estimate â_n. The dither parameter can be slightly different than in Equation (4)(5). The dither may have been removed at the network node, which means that after repetition n, the network node may have access to the signals such as:

For demodulation purposes, this can be equivalent to obtaining a single sample of the form, e.g.

where w has the same distribution as w_m. To compute p(a = x\â_n = y), the following may be used e.g.:

As

the following may be expressed:

As a shorthand notation, q_n(x|y) is used instead of p(a = x\â_n = y).

For example, when the feedback is â_n = y. For example, the expected value of the transmit signal s_n, without any dither, i.e. ,

, which leads to an optimum dither strength parameter that can be obtained by e.g.:

To cancel the direct current, DC, component, the wireless device can transmit the value in the nth repetition, where y ∈ {-3, -1,1,3}. For example the

average energy per repetition can be calculated using the above stated probabilities. The Inventors have noted that energies E_n can again solely depend on the values β _n, much alike the BPSK case, and that performance can solely dependent on β₁ +...+ β _N. The person skilled in the art can thereby formulate an optimization similar to P1 for this case. The disclosed technique is not limited to 4-PAM, and is extendable to any other PAM alphabet of interest.

In one or more examples where modulation schemes with two-dimensional alphabets are used, an extension into QAM-type constellations is considered. A QAM type constellation is two orthogonal PAM constellations. The demonstrations in Equations (16)-(29) can be applied to the I and Q components of a QAM constellation, respectively.

Fig. 4 shows a flow diagram of an example method 200, performed by a network node according to the disclosure. The method 200 may be performed by a network node disclosed herein, such as the network node of Fig. 1 , and Fig. 6.

The method 200 comprises receiving S204, from a wireless device, a value indicative of a first modulation symbol. This corresponds to S104 of Fig. 3. Examples of modulation schemes include one or more of: BPSK, QPSK, M-Quadrature Amplitude Modulation (M- QAM), M-ary single-dimensional modulation where M is a positive integer. The first modulation symbol may be seen as modulation symbol a in Equation (1).

The method 200 comprises determining S205 an estimate of the first modulation symbol by demodulating the first modulation symbol. The estimate is similar to the one of S106 of Fig. 3. In one or more example methods, the estimate is obtained by receiving and demodulating the first modulation symbol at the network node. In other words, the network node can receive and may demodulate (such as using hard demodulation and/or soft demodulation) the first modulation symbol and can then generate an estimate of the received first modulation symbol. For example, the network node receives

, and demodulates the signal to obtain an estimate â of a. The feedback information may be indicative of an estimate â of a.

The method 200 comprises transmitting S206, to the wireless device, feedback information indicative of the estimate of the first modulation symbol. This corresponds to S106 of Fig. 3. The method 200 comprises, receiving S208, from the wireless device, a second modulation symbol. This corresponds to S108 of Fig. 3. In one or more example methods, the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

The method 200 comprises demodulating S210, based on the correctness parameter, the second modulation symbol. In one or more example methods, the correctness parameter is indicative of an error characteristic, such as error rate, of the estimate.

In one or more example methods, the one or more configuration parameters are based on one or more predetermined rules, such as Equations (2) (4) and/or (5). In one or more example methods, the method 200 comprises obtaining the one or more predetermined rules, such as retrieving, based on control signalling, from a memory of the network node, such as receiving from the wireless device. For example, one or more predetermined rules comprises one or more of: a predetermined mapping, a predetermined rule based on quality of the feedback (such as probability that feedback is correct), a predetermined set of values, like a codebook for optimum α_n vectors and power scaling vectors.

In one or more example methods, the dither parameter is based on the estimate and a dither strength parameter, referred to as α_n in earlier Equations.

In one or more example methods, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by selecting, based on the estimate, an alphabet amongst the plurality of alphabets. This is illustrated in Fig. 7. In one or more example methods, the alphabet comprises an ordered set of modulation symbols. In one or more example methods, the method 200 comprises receiving S202, from the wireless device, control signalling indicative of a feedback scheme for configuring the feedback information. This corresponds to S102 of Fig. 3 and illustrated in Fig. 2

In one or more example methods, the control signalling comprises capability signalling indicative of the feedback scheme. In one or more example methods, the capability signalling may indicate a release number and/or an index of a look up table.

In one or more example methods, the method 200 comprises transmitting S203, to the wireless device, information indicative of the feedback scheme to apply at the wireless device.

In one or more example methods, the control signalling comprises a request for activating a feedback scheme. In one or more example methods, the method 200 comprises transmitting, to the wireless device, a response. In one or more example methods, the control signalling is indicative of the one or more configuration parameters of the feedback scheme.

Fig. 5 shows a block diagram of an example wireless device 300 according to the disclosure. The wireless device 300 comprises memory circuitry 301 , processor circuitry 302, and a wireless interface 303. The wireless device 300 may be configured to perform any of the methods disclosed in Fig. 3. In other words, the wireless device 300 may be configured for uplink transmission.

The wireless device 300 is configured to transmit (such as using the wireless interface 303), to a network node, a first modulation symbol.

The wireless device 300 is configured to receive (such as using the wireless interface 303), from the network node, feedback information indicative of an estimate of the first modulation symbol.

In one or more example wireless devices, the estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node. The wireless device 300 is configured to transmit (such as using the processor circuitry 302 and/or using the wireless interface 303), to the network node, a second modulation symbol.

In one or more example wireless devices, the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

The wireless interface 303 is configured for wireless communications via a wireless communication system, such as a 3GPP system, such as a 3GPP system supporting one or more of: New Radio, NR, Narrow-band loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, millimeter-wave communications, such as millimeter-wave communications in licensed bands, such as device-to-device millimeter-wave communications in licensed bands.

The wireless device 300 is optionally configured to perform any of the operations disclosed in Fig. 3 (such as any one or more of S102, S103, S104, S106, S108). The operations of the wireless device 300 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non- transitory computer readable medium (for example, memory circuitry 301) and are executed by processor circuitry 302).

Furthermore, the operations of the wireless device 300 may be considered a method that the wireless device 300 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and/or software.

Memory circuitry 301 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), or other suitable device. In a typical arrangement, memory circuitry 301 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 302. Memory circuitry 301 may exchange data with processor circuitry 302 over a data bus. Control lines and an address bus between memory circuitry 301 and processor circuitry 302 also may be present (not shown in Fig. 5). Memory circuitry 301 is considered a non-transitory computer readable medium.

Memory circuitry 301 may be configured to store information such as predetermined rules, one or more configuration parameters in a part of the memory.

Fig. 6 shows a block diagram of an example network node 400 according to the disclosure. The network node 400 comprises memory circuitry 401 , processor circuitry 402, and a wireless interface 403. The network node 400 may be configured to perform any of the methods disclosed in Fig. 4.

The network node 400 is configured to receive (such as using the wireless interface 403), from a wireless device, a value indicative of a first modulation symbol.

The network node 400 is configured to determine (such as using the processor circuitry 402) an estimate of the first modulation symbol by demodulating the first modulation symbol.

The network node 400 is configured to transmit (such as using the wireless interface 403), to the wireless device, feedback information indicative of the estimate of the first modulation symbol.

The network node 400 is configured to receive (such as using the wireless interface 403), from the wireless device, a second modulation symbol.

In one or more example network nodes the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

The network node 400 is configured to demodulate (such as using the processor circuitry 402), based on the correctness parameter, the second modulation symbol.

The wireless interface 403 is configured for wireless communications via a wireless communication system, such as a 3GPP system, such as a 3GPP system supporting one or more of: New Radio, NR, Narrow-band loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, millimeter-wave communications, such as millimeter-wave communications in licensed bands, such as device-to-device millimeter-wave communications in licensed bands. Processor circuitry 402 is optionally configured to perform any of the operations disclosed in Fig. 4 (such as any one or more of S202, S203, S204, S205, S206, S208, S210). The operations of the network node 400 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non- transitory computer readable medium (for example, memory circuitry 401 ) and are executed by processor circuitry 402).

Furthermore, the operations of the network node 400 may be considered a method that the network node 400 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and/or software.

Memory circuitry 401 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), or other suitable device. In a typical arrangement, memory circuitry 401 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 402. Memory circuitry 401 may exchange data with processor circuitry 402 over a data bus. Control lines and an address bus between memory circuitry 401 and processor circuitry 402 also may be present (not shown in Fig. 6). Memory circuitry 401 is considered a non-transitory computer readable medium.

Memory circuitry 401 may be configured to store predetermined rules, and/or one or more configuration parameters in a part of the memory.

Fig. 7 is a diagram illustrating an example alphabet for QSPK modulation scheme according to this disclosure. The QPSK alphabet illustrated may be denoted by A₀ = {1, i, -1, —i} and A₀(k ) denotes the kth entry in A₀, i.e., A₀(2) = i, etc. The normal system based on repetitions can then be described by e.g.:

Fig. 7 shows the following 4 alphabets:

A₁ = {0,1, e^{i2π /3}, e^{i4π /3}} A₂ = {1,0, e^i2π/3, e^i4π/3} A₃ = { 1, e^{i2π /3},0, e^{i4π /3}} A₄ = {1 , e^i2π/3, e^i4π/3,0}

The alphabets can be seen a different bitmaps in some examples.

A₁ to A₄ are different from A₀ since a “0” is present at different places of the alphabet as illustrated in Fig. 7.

In one or more examples, a change of the alphabet is used (instead of a dither parameter). In repetition 1 the transmitted signal is , where a ∈ {1,2, 3, 4} is the

index to be communicated. In repetitions n=2...N, there is feedback â_n that represents the index a. In repetition n the wireless device can transmit the value . In other

words, the wireless device can select the alphabet to be used based on the feedback information indicative of the estimate â for the next repetition. In one or more examples, the configuration parameters may be determined in closed form, which allows for an optimization of the sequence β _n.

Fig. 8 is a diagram illustrating an example according to this disclosure.

Fig. 8 shows constellation points 801 , 802, 803, 804, 805, 806, 807, 808, 809 of constellation 800.

Fig. 8 illustrates that for a higher constellation e.g. 64 QAM a correct detection causes a retransmission constellation point to move closer to the center (lower power, such as 802 to 802A) while the neighboring constellation points to “zoom out” (to higher powers) as shown in Fig. 8 by constellation point 802 moving to 802A in retransmission.

An erroneous detection would cause a constellation point at the “outskirts” of the constellation diagram as shown with 807 and 807A in 800A, 808 to 808A, 809 to 809A, 802 to 803A. Consequences are that the constellation diagram can be the same for all transmissions and a correct detection (such as 801) does not need to be at “zero power”.

Fig. 9 shows a graph 900 illustrating an example performance of the disclosed technique. The y-axis of the graph 900 represents Bit Error Rate (BER). The x-axis of the graph 900 represents 1/No in dB. Fig. 9 shows numerical results for the disclosed technique vs legacy technique. In Fig. 9, P=N. In other words, the total transmit energy per bit scales linearly with the number of repetitions.

The curves 900A, 901 A, and 902A represent performance, when there is no feedback (legacy), for repetitions N=2, N=10, and N=20.

The curves 900B, 901 B, and 902B represent performance, in case of optimization through P1 (see Equation (9)), for repetitions N=2, N=10, and N=20 respectively. The curves 900C, 901 C, and 902C represent performance, when optimizing using uniform power (see Equation (11 ) and E_n = 1,∀n), for repetitions N=2, N=10, and N=20 respectively.

Fig. 9 shows an example when a total transmit energy per bit scales with number of repetitions N (e.g., P=N).

As illustrated in Fig. 9, there is no substantial loss imposed by a uniform power allocation. It is to be noted that the term “uniform power allocation” only refers to the average power. The disclosed technique may be seen as imposing a much higher variance of power than the legacy. This may also be illustrated in Fig. 11. In other words, although the average power is constant across all repetitions, at later repetitions the wireless device can typically transmit very low energy, but with low probability the wireless device can transmit much larger energy.

Fig. 10 shows a graph 1000 illustrating an example performance of the disclosed technique, in terms of BER. The y-axis of the graph 1000 represents Bit Error Rate (BER). The x-axis of the graph 1000 represents P/No in dB.

The graph 1000 shows an example when P (the total transmit energy per bit) does not scale with number of repetitions N (i.e., P=1).

Curve 1001 represents power scaling for legacy systems, where N is not necessarily equal to 1 as repetitions take place in legacy systems.

Curve 1002 represents the performance, in the case of uniform power allocation, for N=10 repetitions. The curve 1003 represents performance, in the case of uniform power allocation, for N=20 repetitions. The curve 1004 represents performance, in the case of uniform power allocation, for N=40 repetitions. The curve 1005 represents performance, in the case of uniform power allocation, for N=100 repetitions. The curve 1006 represents performance, in the case of uniform power allocation, for N=1000 repetitions. The curve 1007 represents performance, in the case of uniform power allocation, for N=10000 repetitions.

Fig. 10 illustrates the effect of increasing N while keeping the total transmitted energy fixed, i.e., P=1. In this illustration, uniform power is used, and not P1. Since uniform power allocation is almost as efficient as P1 , Fig.10 shows results only for this case. As can be seen, the performance saturates as N -> ∞ , and there is about 1 dB gain of using N ≈∞ repetitions compared to N = 10 repetitions. However, in practical systems, a BER of around 0.1 is sufficient (due to outer error correction). At such BERs, N = 10 repetitions can be sufficient and there is about 1 .8 dB gain over legacy systems. However, without the feedback information, repetitions do not help, i.e., since the total power is

fixed. In Fig. 10, there seems to be a threshold around -1dB. In Appendix A, we prove that this threshold is -0.86 dB. In the figure, it may seem that there are curves to the left of this, but that is a result of the rather high error probabilities displayed in Fig. 10. With infinite number of repetitions, the error rate is 0 whenever 1/N₀ > -0.86 dB

Fig. 11 shows graphs 1101 , 1102, 1103, 1104 illustrating examples of power scaling parameters across repetitions according to this disclosure. In Fig. 11 , uniform power allocation is applied, e.g., not P1 , and a technique where power does not scale with N. The following is set: which represents “high SNR” (see Fig. 10). Although the

average power transmitted per repetition is uniform, the wireless device can transmit nearly 0 power most of the time. When energy is transmitted, it is, however, typically very high power. A “spiky” power profile is therefore obtained.

A power profile may be seen as the probability density function of the transmitted power, parameterized by the repetition stage n. The power profile may be seen as a family or a collection of probability density functions. In other words, a spiky profile may represent a “wide” probability density function.

To investigate how spiky the power profile is, Fig. 11 shows results of β _n over the repetitions. As illustrated, the value of β _n increases at later repetitions, which implies that at later repetitions, the power profile is spikier. The value ∑ β _N given in the plot corresponds to the power gain over a legacy system which would have ∑ β _n=1 . Fig. 12 shows graphs 1201 , 1202, 1203, 1204 illustrating examples of power scaling parameters across repetitions according to this disclosure.

In Fig. 12, the investigation of Fig.11 is repeated, but for low SNR and where the following is set The outcome is that the power profile is spikier at later repetitions, but

the increase is linear rather than exponential-like as in Fig. 11 . The spiky behavior (such as non-uniform average power allocation) can be caused by the adaptation based on the feedback â and to improve and obtain lower error at reception.

Fig. 13 shows graphs 1301 , 1302 illustrating examples of power scaling parameters across repetitions according to this disclosure.

In Fig. 13, P1 is applied. Fig. 13 illustrates how the optimal power profile looks like at “high SNR”. Fig. 13 shows that power does not scale with N. As illustrated, a linear decrease is observed, i.e., later repetitions typically transmit less power on average. At low SNR, the obtained curves are flat. Finally, we mention the disturbing fact that the system is spikier than the legacy system (and has non-uniform average power allocation whenever P1 is used) which can be mitigated by letting different resources within the same OFDM symbol correspond to different repetition indices n. This may result in a much-reduced variance in energy per OFDM symbol.

Examples of methods and products (network node and wireless device) according to the disclosure are set out in the following items:

Item 1 . A method, performed by a wireless device, for uplink transmission, the method comprising: transmitting (S104), to a network node, a first modulation symbol; receiving (S106), from the network node, feedback information indicative of an estimate of the first modulation symbol, wherein the estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node ; and transmitting (S108), to the network node, a second modulation symbol wherein the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

Item 2. The method according to item 1 , wherein the correctness parameter is indicative of an error characteristic of the estimate.

Item 3. The method according to any of the previous items, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by applying, to the first modulation symbol, one or more configuration parameters associated with the feedback information.

Item 4. The method according to item 3, wherein the one or more configuration parameters are based on one or more predetermined rules.

Item 5. The method according to any of items 3-4, wherein the one or more configuration parameters comprise information indicative of one or more of: a dither parameter, a power scaling parameter, a plurality of alphabets.

Item 6. The method according to item 5, wherein the dither parameter is based on the estimate and a dither strength parameter.

Item 7. The method according to any of the previous items, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by selecting, based on the estimate, an alphabet amongst the plurality of alphabets, wherein the alphabet comprises an ordered set of modulation symbols. Item 8. The method according to any of the previous items, the method comprising transmitting (S102), to the network node, control signalling indicative of a feedback scheme for configuring the feedback information.

Item 9. The method according to item 8, wherein the control signalling comprises capability signalling indicative of the feedback scheme.

Item 10. The method according to item 9, the method comprising receiving (S103), from the network node, information indicative of the feedback scheme to apply at the wireless device.

Item 11. The method according to any of items 8-10, wherein the control signalling comprises a request for activating a feedback scheme and wherein the method comprises receiving, from the network node, a response.

Item 12. The method according to any of items 8-11 , wherein the control signalling is indicative of the one or more configuration parameter of the feedback scheme.

Item 13. A method, performed by a network node, the method comprising: receiving (S204), from a wireless device, a value indicative of a first modulation symbol; determining (S205) an estimate of the first modulation symbol by demodulating the first modulation symbol; transmitting (S206), to the wireless device, feedback information indicative of the estimate of the first modulation symbol; receiving (S208), from the wireless device, a second modulation symbol wherein the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate; and demodulating (S210), based on the correctness parameter, the second modulation symbol.

Item 14. The method according to item 13, wherein the correctness parameter is indicative of an error characteristic of the estimate.

Item 15. The method according to any of items 13-14, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by applying, to the first modulation symbol, one or more configuration parameters associated with the feedback information.

Item 16. The method according to item 15, wherein the one or more configuration parameters are based on one or more predetermined rules.

Item 17. The method according to any of items 15-16, wherein the one or more configuration parameters comprise information indicative of one or more of: a dither parameter, a power scaling parameter, a plurality of alphabets.

Item 18. The method according to item 17, wherein the dither parameter is based on the estimate and a dither strength parameter.

Item 19. The method according to any of items 13-17, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by selecting, based on the estimate, an alphabet amongst the plurality of alphabets, wherein the alphabet comprises an ordered set of modulation symbols. Item 20. The method according to any of items 13-19, the method comprising receiving (S202), from the wireless device, control signalling indicative of a feedback scheme for configuring the feedback information.

Item 21. The method according to item 20, wherein the control signalling comprises capability signalling indicative of the feedback scheme.

Item 22. The method according to item 21 , the method comprising transmitting (S203), to the wireless device, information indicative of the feedback scheme to apply at the wireless device.

Item 23. The method according to any of items 20-22, wherein the control signalling comprises a request for activating a feedback scheme and wherein the method comprises transmitting, to the wireless device, a response.

Item 24. The method according to any of items 20-23, wherein the control signalling is indicative of the one or more configuration parameters of the feedback scheme.

Item 25. A wireless device comprising memory circuitry, processor circuitry, and a wireless interface, wherein the wireless device is configured to perform any of the methods according to any of items 1-12.

Item 26. A network node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the network node is configured to perform any of the methods according to any of items 13-24.

The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order, but are included to identify individual elements.

Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

It may be appreciated that Figures comprise some circuitries or operations which are illustrated with a solid line and some circuitries, components, features, or operations which are illustrated with a dashed line. Circuitries or operations which are comprised in a solid line are circuitries, components, features or operations which are comprised in the broadest example. Circuitries, components, features, or operations which are comprised in a dashed line are examples which may be comprised in, or a part of, or are further circuitries, components, features, or operations which may be taken in addition to circuitries, components, features, or operations of the solid line examples. It should be appreciated that these operations need not be performed in order presented. Furthermore, it should be appreciated that not all of the operations need to be performed. The example operations may be performed in any order and in any combination. It should be appreciated that these operations need not be performed in order presented. Circuitries, components, features, or operations which are comprised in a dashed line may be considered optional.

Other operations that are not described herein can be incorporated in the example operations. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations.

Certain features discussed above as separate implementations can also be implemented in combination as a single implementation. Conversely, features described as a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as any subcombination or variation of any sub-combination It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed.

It is to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

It should further be noted that any reference signs do not limit the scope of the claims, that the examples may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than or equal to 10% of, within less than or equal to 5% of, within less than or equal to 1% of, within less than or equal to 0.1 % of, and within less than or equal to 0.01% of the stated amount. If the stated amount is 0 (e.g., none, having no), the above recited ranges can be specific ranges, and not within a particular % of the value.

The various example methods, devices, nodes, and systems described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer- readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program circuitries may include routines, programs, objects, components, data structures, etc. that perform specified tasks or implement specific abstract data types. Computer-executable instructions, associated data structures, and program circuitries represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes. Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

APPENDIX A

• Appendix A: Limit to energy efficiency

Define

The performance of the system is determined by s_N which represents the total received power after N repetitions. Manipulations with the equations yield

Expressed with the erfc-function, this is

Expressing erfc in terms of erf, i.e. , erfc(x)=1-erf(x) gives

Our goal is now to show that there is a smallest value L* such that when we have

that , it follows that the error probability is 0.

We have

Define x = n/N. With that, we can write, as N grows large

The function value s(x) is given by s_n for the value of n that results in n/N = x.

With assumption that fixed, the above equation is

equivalent to

Interpreting the LHS as the differential ds/dx we have the separable differential equation

which gives

Alternatively, t = s/N₀. The differential equation to solve is:

The advantage of this for is that we get rid of the lonely N₀ and solely depends on snr ratio P/N₀.

Integrating both sides, gives

for some constant C. Now, the LHS of the above has a closed form solution, but one which is very messy to deal with.

However, progress can be made nonetheless. Let the LHS of the above be denoted by f (s,N 0). An expression for this has been found:

This may also be expressed as:

Two important values can be easily found,

This is precisely what is needed. The initial condition s(0) = 0 gives

so that

We therefore need to find the value of z = s(1) satisfying

Whenever the communication is error free, we have that s(1) = ∞ , which implies

so that

Therefore,

Claims

1 . A method, performed by a wireless device, for uplink transmission, the method comprising: transmitting (S104), to a network node, a first modulation symbol; receiving (S106), from the network node, feedback information indicative of an estimate of the first modulation symbol, wherein the estimate of the first modulation symbol is determined based on a reception of the first modulation symbol at the network node; and transmitting (S108), to the network node, a second modulation symbol wherein the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate.

2. The method according to claim 1 , wherein the correctness parameter is indicative of an error characteristic of the estimate.

3. The method according to any of the previous claims, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by applying, to the first modulation symbol, one or more configuration parameters associated with the feedback information.

4. The method according to claim 3, wherein the one or more configuration parameters are based on one or more predetermined rules.

5. The method according to any of claims 3-4, wherein the one or more configuration parameters comprise information indicative of one or more of: a dither parameter, a power scaling parameter, a plurality of alphabets.

6. The method according to claim 5, wherein the dither parameter is based on the estimate and a dither strength parameter.

7. The method according to any of the previous claims, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by selecting, based on the estimate, an alphabet amongst the plurality of alphabets, wherein the alphabet comprises an ordered set of modulation symbols.

8. The method according to any of the previous claims, the method comprising transmitting (S102), to the network node, control signalling indicative of a feedback scheme for configuring the feedback information.

9. The method according to claim 8, wherein the control signalling comprises capability signalling indicative of the feedback scheme.

10. The method according to claim 9, the method comprising receiving (S103), from the network node, information indicative of the feedback scheme to apply at the wireless device.

11. The method according to any of claims 8-10, wherein the control signalling comprises a request for activating a feedback scheme and wherein the method comprises receiving, from the network node, a response.

12. The method according to any of claims 8-11 , wherein the control signalling is indicative of the one or more configuration parameter of the feedback scheme.

13. A method, performed by a network node, the method comprising: receiving (S204), from a wireless device, a value indicative of a first modulation symbol; determining (S205) an estimate of the first modulation symbol by demodulating the first modulation symbol; transmitting (S206), to the wireless device, feedback information indicative of the estimate of the first modulation symbol; receiving (S208), from the wireless device, a second modulation symbol wherein the second modulation symbol is a repetition of the first modulation symbol adapted based on a correctness parameter of the estimate; and demodulating (S210), based on the correctness parameter, the second modulation symbol.

14. The method according to claim 13, wherein the correctness parameter is indicative of an error characteristic of the estimate.

15. The method according to any of claims 13-14, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by applying, to the first modulation symbol, one or more configuration parameters associated with the feedback information.

16. The method according to claim 15, wherein the one or more configuration parameters are based on one or more predetermined rules.

17. The method according to any of claims 15-16, wherein the one or more configuration parameters comprise information indicative of one or more of: a dither parameter, a power scaling parameter, a plurality of alphabets.

18. The method according to claim 17, wherein the dither parameter is based on the estimate and a dither strength parameter.

19. The method according to any of claims 13-17, wherein the repetition of the first modulation symbol is adapted based on the correctness parameter of the estimate by selecting, based on the estimate, an alphabet amongst the plurality of alphabets, wherein the alphabet comprises an ordered set of modulation symbols.

20. The method according to any of claims 13-19, the method comprising receiving (S202), from the wireless device, control signalling indicative of a feedback scheme for configuring the feedback information.

21. The method according to claim 20, wherein the control signalling comprises capability signalling indicative of the feedback scheme.

22. The method according to claim 21 , the method comprising transmitting (S203), to the wireless device, information indicative of the feedback scheme to apply at the wireless device.

23. The method according to any of claims 20-22, wherein the control signalling comprises a request for activating a feedback scheme and wherein the method comprises transmitting, to the wireless device, a response.

24. The method according to any of claims 20-23, wherein the control signalling is indicative of the one or more configuration parameters of the feedback scheme.

25. A wireless device comprising memory circuitry, processor circuitry, and a wireless interface, wherein the wireless device is configured to perform any of the methods according to any of claims 1-12.

26. A network node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the network node is configured to perform any of the methods according to any of claims 13-24.