Devices and methods for analog and digital data transmission

Abstract

Disclosed are devices (1, 2, 3) for and methods (4, 5) of analog and digital data transmission. A transmitter device (1) comprises a control circuit (11), a sampling and buffering circuit (12), a modulation circuit (14), and a mapping circuit (15). The control circuit (11) is configured to send a scheduling request to a controller device (3) for analog and digital data transmission, and receive a control signal for the transmission from the controller device (3). The control signal comprises communication resources for the transmission; and a modulation and coding scheme, MCS, indication for the transmission. The sampling and buffering circuit (12) is configured to sample discrete-time source data (u[n]) from analog source data (U(t)), and to buffer the discrete-time source data (u[n]). The modulation circuit (14) comprises parallel analog and digital branches, respectively configured to modulate the discrete-time source data (u1:K[n], u1:K'[n], w1:K'[n]) to discrete-time encoded data (x1:N[n]) in accordance with the MCS indication. The mapping circuit (15) is configured to map the discrete-time encoded data (x1:N[n]) to a continuous-time transmission waveform (X1:N(t)) in accordance with the MCS indication. This provides efficient communications based on coexisting analog and digital transmission schemes.

Description

[0001]DEVICES AND METHODS FOR ANALOG AND DIGITAL DATA TRANSMISSION TECHNICAL FIELDThe present disclosure relates generally to the field of telecommunication, and in particular to devices and methods for analogand digital data transmission. BACKGROUND ART As known in the art, digital transmission schemes notoriously strive for a perfect decoding at the receiver side. However, in transmission of sensing data, perfect decoding by the receiver(s) may not be mandatory and the receiver(s) can obtain enough information (not all) about the sensing data without perfect decoding.In digital transmission schemes, the transmitted signal should be picked from a limited number of the modulation constellationpoints. Therefore, in order to transmit a continuous data symbol (vs discrete data symbol), the transmitter first quantizes the data, and then encodes the data to make it robust against the channel noise (channel coding) and finally modulates the encoded data by picking a constellation point among the limited constellation points. The choice of the quantization order, channel coding rate, and the modulation order is based on the application requirement and the quality of the channel. The disadvantages of digital transmission schemes are as follows:^ The communication performance highly depends on the CSI at the transmitter.^ Digital transmission schemes show threshold and saturation effects.^ In broadcast channel, the communication parameters are selected based on the weakest channel, which is not favorablefor the receivers with good channel qualities.^ The quantizer and channel coding components add computational burden to devices.^ Digital channel coding techniques can notably degrade the performance of the system for scenarios like broadcasting tomassive number of users, high mobility scenario, etc.^ Digital channel coding techniques don’t provide a remarkable coding gain and add a significant overhead with respect tothe data payload size in extremely short blocklength regime (e.g. 10 or 20 bits).^ Perfect decoding is not always needed where only a rough estimation could be sufficient. The selection of an over- constrained modulation and coding scheme (MCS) will result in a suboptimal use of channel resources.The aforementioned problems may similarly appear in other emerging applications such as communication for computations, distributed learning, etc.As a result, it can be observed that the communication protocols need to be more flexible and cover more general schemes tobe able to satisfy the new KPIs of the emerging applications. SUMMARY It is an object to overcome the above-mentioned and other drawbacks. 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 transmitter device for analog and digital data transmission is provided. The transmitter devicecomprises a control circuit, a sampling and buffering circuit, a modulation circuit, and a mapping circuit. The control circuit is configured to send a scheduling request to a controller device for analog and digital data transmission, and receive a control signal for the transmission from the controller device. The control signal comprises communication resources for thetransmission; and a modulation and coding scheme, MCS, indication for the transmission. The sampling and buffering circuitis configured to sample discrete-time source data from analog source data, and to buffer the discrete-time source data. The modulation circuit comprises parallel analog and digital branches, respectively configured to modulate the discrete-time sourcedata to discrete-time encoded data in accordance with the MCS indication. The mapping circuit is configured to map thediscrete-time encoded data to a continuous-time transmission waveform in accordance with the MCS indication. “Digital transmission” as used herein may refer to a transmission based on a limited number of constellation points and on anobjective to perfectly reconstruct the transmitted signal. To do so, the transmitter may first quantize continuous-valued sourcedata. Then the quantized data may be passed through a channel coding block, which makes the data robust against channel noise and other sources of signal deformation in the channel. Next, the encoded data may be mapped to one of the possiblelimited constellation points and transmitted by a carrier waveform. The picked quantization order, channel coding rate, and themodulation order are based on the application requirement and the channel condition.“Analog transmission” as used herein may refer to a transmission based on a potentially infinite set of constellation points andon an objective to minimize a distortion in an estimation of the transmitted data. After passing the source data through a channel coding unit it may simply be transmitted by a carrier waveform.Potential benefits of coexisting analog and digital transmission schemes include:^ Graceful degradation over wide SNR range, and as a result, the receiver can acquire less distorted information if thechannel condition is better than the expectation and, also the receiver can extract some information if the channel condition is worse than the expectation. In other words, a sensitivity of the performance of the system to CSI knowledge at thetransmitter is significantly less, which results in less pilot overhead.^ A combination of analog and digital transmission is more flexible to the different KPIs. For example, the analogtransmission scheme can be designed to minimize a distortion of a decoded message at the receivers for a cost function of interest, in contrast to the digital transmission scheme which aims to provide a perfect decoding condition.^ For extremely short blocklength communication, analog transmission can outperform digital transmission.The analog branch may be configured to optimize performance metrics of estimated discrete-time source data decodable fromthe transmission, in accordance with the MCS indication.In a possible implementation form, the MCS indication may be indicative of one or more of: a distortion metric, a maximum distortion, a source PDF of the discrete-time source data, a coding rate, a minimum signal-to-noise ratio, SNR, and a received signal strength indicator, RSSI.In a possible implementation form, the analog branch may comprise an analog coding circuit, configured to modulate thediscrete-time source data to the discrete-time encoded data such that a loss function of the estimated discrete-time source datais minimized.In a possible implementation form, the loss function may be calculated in accordance with one or more of: the distortion metric,the source PDF, an input block length, an output block length, a channel model, and the minimum SNR.In a possible implementation form, the analog branch may further comprise a PDF reshaping circuit, configured to convert thediscrete-time source data having the source PDF to the discrete-time source data having a PDF optimized for the transmission.In a possible implementation form, the transmitter device may further comprise a source coding circuit, configured to convertthe discrete-time source data to compressed discrete-time source data.In a possible implementation form, the analog coding circuit may be configured to maximize an average of a ratio of a Euclidiandistance of each pair of the discrete-time encoded data, and an Euclidian distance of each corresponding pair of the discrete-time source data, such that the loss function of the estimated discrete-time source data is minimized.In a possible implementation form, the analog coding circuit may comprise a repetition encoder.In a possible implementation form, the analog branch may comprise a joint source channel coding circuit, configured tomaximize an average of a ratio of a Euclidian distance of each pair of the discrete-time encoded data, and an Euclidian distanceof each corresponding pair of the discrete-time source data, such that the loss function of the estimated discrete-time sourcedata is minimized.In a possible implementation form, the mapping circuit may comprise one or more of: a multiplexing circuit, configured tomultiplex the discrete-time encoded data of the parallel analog and digital branches, an Inverse Fast Fourier Transform, IFFT, circuit, and a guard time insertion and time windowing circuit.According to a second aspect, a controller device for analog and digital data transmission is provided. The controller devicecomprises a control circuit, configured to receive a scheduling request from a transmitter device for analog and digital data transmission, and send a control signal for the transmission to the transmitter device. The control signal comprises communication resources for the transmission; and a modulation and coding scheme, MCS, indication for the transmission.According to a third aspect, a receiver device for analog and digital data transmission is provided. The receiver device comprisesa demapping circuit and a demodulation circuit. The demapping circuit is configured to demap discrete-time encoded data from a continuous-time reception waveform in accordance with a modulation and coding scheme, MCS, indication. Thedemodulation circuit comprises parallel analog and digital branches, respectively configured to demodulate estimated discrete-time source data from the discrete-time encoded data in accordance with the MCS indication.The analog branch may be configured to optimize performance metrics of the estimated discrete-time source data in accordancewith the MCS indication.In a possible implementation form, the MCS indication may be indicative of one or more of: a distortion metric, a maximumdistortion, a source PDF of the discrete-time source data, a coding rate, a minimum signal-to-noise ratio, SNR, and a received signal strength indicator, RSSI. In a possible implementation form, the analog branch may comprise an analog decoding circuit, configured to demodulate the estimated discrete-time source data from the discrete-time encoded data such that a loss function of the estimated discrete-time source data is minimized.In a possible implementation form, the loss function may be calculated in accordance with one or more of the distortion metric,the source PDF, an input block length, an output block length, a channel model, and the minimum SNR.In a possible implementation form, the analog branch may further comprise a PDF de-reshaping circuit, configured to convertthe estimated discrete-time source data having a PDF optimized for the transmission to the estimated discrete-time source data having the source PDF.In a possible implementation form, the receiver device may further comprise a source decoding circuit, configured to convertthe estimated discrete-time source data to decompressed estimated discrete-time source data.In a possible implementation form, the analog decoding circuit may be configured to determine the estimated discrete-timesource data for which the distortion of the PDF is minimized, among the set of all possible values of the estimated discrete- time source data.In a possible implementation form, the analog decoding circuit may comprise a repetition decoder.In a possible implementation form, the analog branch may comprise a joint source channel decoding circuit, configured todetermine the estimated discrete-time source data for which the distortion of the PDF is minimized, among the set of all possiblevalues of the estimated discrete-time source data. Potential benefits of the joint source channel (de)coding include an avoidance of the cliff effect of digital transmission schemes. i.e., if the channel quality is below a threshold, the receiver almost cannot extract any information (threshold effect) and if the receiver has much better channel quality than the one that the system is designed for, the receiver doesn’t get any extra gain from its good channel quality (saturation effect).In a possible implementation form, the demapping circuit may comprise one or more of: a guard time removal circuit, a FastFourier Transform, FFT, circuit, and a demultiplexing circuit, configured to demultiplex the discrete-time encoded data of the parallel analog and digital branches.In a possible implementation form, the distortion metric may comprise one of: a mean squared error, MSE, a mean absoluteerror, MAE, and a symmetric mean absolute percentage error, SMAPE.In a possible implementation form, the source PDF may comprise one of: a continuous uniform distribution, a Gaussiandistribution, and an exponential distribution.According to a fourth aspect, a method of controlling analog and digital data transmission is provided. The method comprisessending a scheduling request to a controller device for analog and digital data transmission; and receiving a control signal for the transmission from the controller device. The control signal comprises communication resources for the transmission; and a modulation and coding scheme, MCS, indication for the transmission.According to a fifth aspect, a method of controlling analog and digital data transmission is provided. The method comprisesreceiving a scheduling request from a transmitter device for analog and digital data transmission; allocating communication resources for the transmission; obtaining an estimation of channel state information, CSI, for the communication resources; selecting a modulation and coding scheme, MCS, indication for the transmission in accordance with a distortion metric, the communication resources, the CSI, and a source probability density function, PDF, of discrete-time source data; and sending a control signal for the transmission to the transmitter device. The control signal comprises the communication resources for the transmission; and the MCS indication. The MCS indication may be indicative of one or more of: a distortion metric, a maximum distortion, the source PDF of thediscrete-time source data, a coding rate, a minimum signal-to-noise ratio, SNR, and a received signal strength indicator, RSSI.According to a sixth aspect, a computer program is provided, comprising a program code for performing the method of thefourth aspect or any of its implementations or the method of the fifth aspect or any of its implementations when executed on acomputer. BRIEF DESCRIPTION OF DRAWINGS The above-described aspects and implementations will now be explained with reference to the accompanying drawings, in which the same or similar reference numerals designate the same or similar elements. The drawings are to be regarded as being schematic representations, and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent tothose skilled in the art.FIG. 1 illustrates a transmitter device 1 and a receiver device 2 in accordance with implementations of the presentdisclosure; FIG.2 illustrates a transmitter device 1 and a receiver device 2 in accordance with further implementations of the present disclosure;FIGs. 3, 4 illustrate a mapping circuit 15 and a demapping circuit 25 in accordance with implementations of the presentdisclosure; andFIG. 5 illustrates a flow sequence and interaction of methods 4, 5 in accordance with implementations of the presentdisclosure.DETAILED DESCRIPTIONS OF DRAWINGSIn the following description, reference is made to the accompanying drawings, which form part of the disclosure, and whichshow, by way of illustration, specific aspects of implementations of the present disclosure or specific aspects in whichimplementations of the present disclosure may be used. It is understood that implementations of the present disclosure may beused in other aspects and comprise structural or logical changes not depicted in the figures. The following detailed description,therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.For instance, it is understood that a disclosure in connection with a described method may also hold true for a corresponding apparatus or system configured to perform the method and vice versa. For example, if one or a plurality of specific method steps are described, a corresponding device may include one or a plurality of units, e.g. functional units, to perform the describedone or plurality of method steps (e.g. one unit performing the one or plurality of steps, or a plurality of units each performingone or more of the plurality of steps), even if such one or more units are not explicitly described or illustrated in the figures. On the other hand, for example, if a specific apparatus is described based on one or a plurality of units, e.g. functional units, a corresponding method may include one step to perform the functionality of the one or plurality of units (e.g. one step performing the functionality of the one or plurality of units, or a plurality of steps each performing the functionality of one or more of the plurality of units), even if such one or plurality of steps are not explicitly described or illustrated in the figures. Further, it isunderstood that the features of the various exemplary implementations and / or aspects described herein may be combined witheach other, unless specifically noted otherwise.FIG. 1 illustrates a transmitter device 1 and a receiver device 2 in accordance with implementations of the present disclosure.The transmitter device 1 and the receiver device 2 are respectively configured for analog and digital data transmission. An upper portion of FIG.1 illustrates the transmitter device 1 and a lower portion of FIG.1 illustrates the receiver device 2.For example, a point-to-point communication may involve that the transmitter device 1 forms part of a user equipment, UE, ofa mobile network and that the receiver device 2 forms part of a base station, BS, such as a gNB, of the afore-mentioned mobilenetwork. However, it should be noted that also point-to-multipoint (in particular broadcast) communication to multiple receiverdevices 2 may be implemented in accordance with the following. The transmitter device 1 comprises a control circuit 11, a sampling and buffering circuit 12, a modulation circuit 14, and a mapping circuit 15, and may further comprise a source coding circuit 13. The control circuit 11 may comprise a microprocessor, for example. The control circuit 11 is configured to send (i.e., initiate a sending of) a scheduling request to a controller device 3 for analog and digital data transmission, and receive a control signal for the transmission from the controller device 3.The control signal comprises communication resources for the transmission, and a modulation and coding scheme, MCS,indication for the transmission. The MCS indication may be indicative of one or more of: a distortion metric, a maximum distortion, a source PDF of thediscrete-time source data u[n], a coding rate, a minimum signal-to-noise ratio, SNR, and a received signal strength indicator,RSSI. Note that throughout the present disclosure, continuous-time signals are denoted by (t), and discrete-time signals arefollowed by [n].The distortion metric may comprise one of: a mean squared error, MSE, a mean absolute error, MAE, and a symmetric meanabsolute percentage error, SMAPE. That is to say, different objectives or metrics may be defined to measure an estimationperformance, based on the application demands. Moreover, the analog channel coding can be optimized for that metric. MSE measures an average of the squares of errors ^[(^ − ^)^], MAE measures an average of the absolute errors ^[|^ − ^|], andSMAPE measures an accuracy based on a relative error 100 ∙ ^ ^^|^^^| |^|^|^|^ .The source PDF may comprise one of: a continuous uniform distribution, a Gaussian distribution, and an exponentialdistribution. The source PDF is another factor that affects the channel coding performance and the selected MCS should bebased on the PDF of the source data. Although there is a PDF reshaping circuit 141 provided, a dramatic change in the PDF distribution of the source data can degrade the performance of the system. Therefore, the MCS set should cover several PDF distributions of the source data. Continu These distributions are non-binding examples, and other distributions may be deployed as well. The coding rate may be indicative of the ratio of the input symbol size to the output symbol size. The coding rate can be eithermore, equal, or less than one. A coding rate more than one involves adding some redundancy to the signal to make it morerobust, if there are enough wireless communication resources., whereas a coding rate less than one involves compression of the data, if the wireless resources are limited, such that the estimated data at the receiver, suffers from minimum possible distortion.The sampling and buffering circuit 12 is configured to sample discrete-time source data u[n] from analog source data U(t), andto buffer the discrete-time source data u[n]. To this end, the sampling and buffering circuit 12 may comprise a sampling circuit (“source sampler”) 121 and a buffering circuit (“buffer”) 122, such as a first-in first-out, FIFO, buffer being based on a solid-state memory.The sampling circuit 121 may be configured to take samples of the source of data U(t). Therefore, an output of the samplingcircuit 121, the discrete-time source data u[n], is discrete over time but continuous in value. The sampling rate can be chosenbased on the available communication resources, the application requirement, etc.The buffering circuit 122 may be configured to keep up to ^ last samples of the discrete-time source data u[n], and to providethis set of samples as u1:K[n] at its output (where 1:K identifies samples “1 to K”).The source coding circuit (“source coding”) 13, if provided, is configured to convert the discrete-time source data u1:K[n] tocompressed discrete-time source data u1:K’[n], w1:K’[n] (note that in absence of the optional PDF reshaping circuit 141 its outputw1:K’[n] may correspond to the output u1:K’[n] of the source coding circuit 13, so that both outputs u1:K’[n], w1:K’[n] are providedas the compressed discrete-time source data. This multi-designation principle applies throughout the present disclosure). Theobjective of this circuit is to remove any existing correlation between the K input samples, thereby performing data compressionto K’ < K samples. In an ideal case, there is no correlation between the output symbols u1:K’[n].The modulation circuit 14 comprises parallel analog and digital branches, respectively being configured to modulate the discrete-time source data u1:K[n], u1:K’[n], w1:K’[n] to discrete-time encoded data x1:N[n] in accordance with the MCS indication. The analog branch of the modulation circuit 14 may be configured to optimize performance metrics of estimated discrete-timesource data û1:K[n], û1:K’[n], ŵ1:K’[n] decodable from the transmission, in accordance with the MCS indication.Therefore, the analog branch of the modulation circuit 14 may comprise a PDF reshaping circuit (“PDF reshaper”) 141,configured to convert the discrete-time source data u1:K[n], u1:K’[n] having the source PDF to the discrete-time source dataw1:K’[n] having a PDF optimized for the transmission. The purpose of this block is to improve the performance of analogchannel coding. The analog branch of the modulation circuit 14 may further comprise an analog coding circuit (“analog coding”) 142,configured to modulate the discrete-time source data u1:K[n], u1:K’[n], w1:K’[n] (uncompressed, compressed, or reshaped,respectively) to the discrete-time encoded data x1:N[n] such that a loss function of the estimated discrete-time source data û1:K[n],û1:K’[n], ŵ1:K’[n] (uncompressed, compressed, or un-de-reshaped) is minimized.This loss function may be calculated in accordance with one or more of the distortion metric, the source PDF, an input blocklength K, K’, an output block length N, a channel model, and the minimum SNR.That is to say, the modulation circuit 14 is configured to minimize the distortion between the discrete-time source data u1:K’[n]and the estimated discrete-time source data û1:K’[n].The input of this block is a sequence of K’ continuous (in value) numbers w1:K’[n]. The output of this block is a sequence ofcontinuous (in value) numbers x1:N[n]. The N symbols are placed in the wireless resources (time frequency grid) according toresource allocation constraints, and locations are indicated in a separate control signal (see FIG.5). The main objectives of this block are to make the signal robust against channel noise and interference, to enable estimation of the ^^symbols with a low distortion, and also to enable the receiver to detect the cases that it is likely that the estimation error be above a specific level.The analog coding may be designed to minimize the expected estimation distortion for a specific range of signal to noise (SNR),for given cost function (e.g., mean square error), input PDF (e.g., normal distribution), input length (i.e., K’), and output length(i.e., N) and a given channel model (e.g., additive white Gaussian noise).The analog coding circuit 142 may be configured to maximize an average of a ratio of a Euclidian distance of each pair of the discrete-time encoded data x11:N = h(w11:K’, x21:N = h(w21:K’)) and an Euclidian distance of each corresponding pair of thediscrete-time source data w21:K’ (i.e., pair of codewords), such that the loss function of the estimated discrete-time sourcedata û1:K[n], û1:K’[n], ŵ1:K’[n] is minimized.Therefore, an example of a good encoder maximizes the following objective function: where, ℎ(. ) denotes the analog encoder, ^^^^(. ) represents the Euclidian distance and ^^^:^^ represent two distinct inputs. In particular, the analog coding circuit 142 may comprise a repetition encoder. The repetition encoder is a popular analog encoder due to its simplicity in implementation, such that the encoder repeats each ^ symbol^^times, as follows: On the other side, for analog decoder, one of the common designing objectives of a good decoder is it to estimate the message which minimizes the expected distortion, as follows: where ^(. ) denotes the analog decoder and ^^(. ) is the probability of a random variable, ^(, ) indicates the distortion, and^(^^:^^) is the set of all possible values for ^^:^^ .Beside the minimizing the expected distortion for a point to point channel, there are some other factors in designing a good analog encoder / decoder block, such as^ Low hardware complexity and low energy consumptions.^ Low latency in encoding and decoding.^ Guaranteeing a maximal risk measure for the distortion, i.e. ^^(^(^^:^^, ^^:^^) > ^) > ^, where the function ^(. ) denotes the distortion function, ^^:^^ is the source data, is the estimation of the source data at the receiver, ^^(. )is the probability, ^ is the threshold of the acceptable distortion level, and ^ is the tolerable probability that the distortionbe less than the acceptable distortion level.^ Design the encoder / decoder such that, the receiver be capable to jointly decode multiple received signals. The equivalentmathematical representation of this case is ^^[^] = ∑^^^^ ^^^ [^] + ^ ,where ^ is the number of active users that the receiver aims to decode their transmission, and ^^^[^]denotes the discrete channel representation of the transmission signal of user ^ at the ^^^channel use, and ^^[^] represents the discrete channel representation of the observed signal by the receiver at the ^^^channel use.^ Robustness against the interference signals coming from the other transmissions in the network. The equivalentmathematical representation of this case is ^^[^] = ^^[^] + ∑^^^^ ^^[^] + ^ ,where ^^[^] denotes the interference signal transmitted by the source ^.The digital branch of the modulation circuit 14 may comprise a quantization circuit (“quantizer”) 144, configured to quantizethe continuous input data to discrete values. The quantizer block can be designed such that the average quantization distortionbe minimized. A further input of this block is the quantization order which indicates the size of the set of possible outputs.The digital branch of the modulation circuit 14 may further comprise a digital coding circuit (“digital coding”) 145. The inputof this block is a sequence of K” discrete numbers w1:K”[n]. The output of this block is a sequence of N” discrete numbersx’1:N”[n]. Similar to the analog coding circuit 142, the goal of this block is to make the signal robust against channel noise and to enable the receiver to detect wrong message decoding. A further input of this block is the coding rate R = K” / N”. The digital branch of the modulation circuit 14 may further comprise a symbol mapping circuit (“symbol mapper”) 147, configured to select a constellation point among the possible set, based on the encoded sequence x’1:N”[n].Note that the mapping circuit 15 may be connected to at least one of the analog branch and the digital branch of the modulationcircuit 14, in accordance with the desired transmission scheme.For example, co-existence of digital and analog communication can be in a hybrid format, such that part of the source data is transmitted via the digital branch of the transmitter device 1 (e.g., it can be the part of the source data, based on the application interest, that should be decoded perfectly at the receiver device 2) and part of the source data is transmitted via the analog branch of the transmitter device 1. Note that the analog and digital transmitted data doesn’t necessarily need to be disjoint. Theswitch shown in FIG. 1 is replaced by a function ^(. ) of the outputs of the analog and digital modulation part, which is mappedto the waveform. The function ^(. ) can be a linear function (e.g., a weighted sum function) or a nonlinear function.For the hybrid analog and digital case, a combination of MCSs can be chosen (i.e., the selected combination of the MCSsshould be supported by the protocols). Moreover, it is feasible to choose different MCS, for transmission within each communication resources. At the receiver side, the analog and digital modulated signal can be decoded either jointly or in a successive manner depending on the system design.The mapping circuit 15 is configured to map the discrete-time encoded data x1:N[n] to a continuous-time transmission waveformX1:N(t) in accordance with the MCS indication.More specifically, the mapping circuit 15 is configured to map the constellation point to a waveform. In amplitude modulation(AM), for example, the input-output relation of this block is^^(^) = ^^ ∗ ^(^) ∗ exp (2^^^^)where, xi is the constellation point, a(t) is the waveform and fc is the carrier frequency (AM single tone modulation). In case ofanalog modulation, xi may take almost infinite possible values, and if digital modulation is used, xi may take some specificvalues. Note that the channel input ^^ can take real values as well as complex values.The receiver device 2 comprises a demapping circuit 25 and a demodulation circuit 24.The receiver device 2 may further comprise a source decoding circuit 23.The demapping circuit 25 is configured to demap discrete-time encoded data y1:N[n] from a continuous-time receptionwaveform Y1:N(t) in accordance with the MCS indication. That is to say, the demapping circuit 25 separates the carrier waveformfrom the signal, for example using a matched filter. The MCS indication may be indicative of one or more of: a distortion metric, a maximum distortion, a source PDF of thediscrete-time source data u[n], a coding rate, a minimum signal-to-noise ratio, SNR, and a received signal strength indicator,RSSI. The distortion metric may depend on the application of interest, and may comprise one of: a mean squared error, MSE, a mean absolute error, MAE, and a symmetric mean absolute percentage error, SMAPE. The source PDF may comprise one of: a continuous uniform distribution, a Gaussian distribution, and an exponentialdistribution.The demodulation circuit 24 comprises parallel analog and digital branches, respectively configured to demodulate estimateddiscrete-time source data û1:K[n], û1:K’[n], ŵ1:K’[n] from the discrete-time encoded data y1:N[n] in accordance with the MCSindication. The analog branch of the demodulation circuit 24 may be configured to optimize performance metrics of the estimated discrete-time source data û1:K[n], û1:K’[n], ŵ1:K’[n] in accordance with the MCS indication.To this end, the analog branch of the demodulation circuit 24 may comprise an analog decoding circuit (“analog decoding”)242, configured to demodulate the estimated discrete-time source data û1:K[n], û1:K’[n], ŵ1:K’[n] from the discrete-time encodeddata y1:N[n] such that a loss function of the estimated discrete-time source data û1:K[n], û1:K’[n], ŵ1:K’[n] is minimized.This loss function may be calculated in accordance with one or more of the distortion metric, the source PDF, an input blocklength N, an output block length K, K’, a channel model, and the minimum SNR.The analog decoding circuit 242 may be configured to determine the estimated discrete-time source data û1:K[n], û1:K’[n],ŵ1:K’[n] for which the distortion of the PDF is minimized, among the set of all possible values of the estimated discrete-timesource data û1:K[n], û1:K’[n], ŵ1:K’[n].The analog decoding circuit 242 may comprise a repetition decoder. The analog branch of the demodulation circuit 24 may further comprise a PDF de-reshaping circuit (“PDF de-reshaper”) 241,configured to convert the estimated discrete-time source data ŵ1:K’[n] having a PDF optimized for the transmission to theestimated discrete-time source data u1:K[n], u1:K’[n] having the source PDF. In other words, this block may perform a reversefunction of the PDF reshaping circuit 141.The digital branch of the demodulation circuit 24 may comprise a symbol de-mapping circuit (“symbol de-mapper”) 247. This block may perform a reverse function of the symbol mapping circuit 147. The digital branch of the demodulation circuit 24 may further comprise a digital decoding circuit (“digital decoding”) 245, configured to estimate the input sequence of the digital coding circuit 145. The digital branch of the demodulation circuit 24 may further comprise a data reconstruction circuit (“data reconst.”) 244, configured to reconstructs the original data from the estimated sequence.The source decoding circuit 23, if provided, is configured to convert the estimated discrete-time source data û1:K’[n], ŵ1:K’[n]to decompressed estimated discrete-time source data û1:K[n].As a possible extension, the coexistence of the analog and digital transmission scheme may involve a joint design of the analog and digital transmission schemes (i.e., merged digital and analog branches in the transmitter device 1 and the receiver device 2). The objective of the digital part of the transmission is a reliable decoding, and the objective of the analog part of the transmission is to provide a minimize the distortion such that the overall performance of the communication fulfills the application requirements.FIG. 2 illustrates a transmitter device 1 and a receiver device 2 in accordance with further implementations of the presentdisclosure.An alternative implementation of the transmitter and receiver structure depicted in FIG. 1 is shown in FIG. 2, wherein thesource and channel coding circuits are combined.More specifically, the analog branch of the modulation circuit 14 may comprise a joint source channel coding circuit 143, andthe analog branch of the demodulation circuit 24 may comprise a joint source channel decoding circuit 243.In this case, the functionality of the joint source channel coding circuit 143 is to remove the existing correlations between theinput symbols to compress the signal, and at the same time, improve the robustness of the transmitted signal against the channelnoise and other sources of the signal deformation to improve the overall performance of the system in estimation of the source symbols at the receiver. For the analog transmission scheme, similar to the aforementioned property for analog encoder, the design parameter of a joint source channel encoder can be to maximize the average of the ratio of the Euclidian distances between each pair of codewords to the Euclidian distance between the corresponding signal of that pair, as follows: For the digital transmission scheme, one of the possible objectives of joint source channel encoder can be as follows: At the receiver side, the joint source channel decoding circuit 246 may estimate the transmitted signal and meanwhile add theexpected correlations between the symbols to reconstruct the source symbols. A maximum likelihood, ML, estimator is one ofthe possible choices, as follows: ^(^^:^) ∶= ^^^^^^^^:^ ^^(^^:^|^^:^). Hence, the joint source channel decoding circuit 243, if provided, is configured to determine the estimated discrete-time sourcedata û1:K[n] for which the distortion of the PDF is minimized, among the set of all possible values of the estimated discrete-time source data û1:K[n].As a possible extension, if the system supports different waveforms for the analog and digital carrier waveforms, the jointsource channel coding 143 can be combined with mapping circuit 15. In this case, the input of joint channel coding andwaveform design is ^^ symbols and the output of this unit is a signal x(t) continuous in time, following instructions of acontroller device 3 (see FIG. 5) in terms of the utilized time and frequency slots, the interference it generates for the other transmission, etc., meanwhile providing an acceptable level of distortion in the estimation at the receiver device 2.FIGs. 3, 4 illustrate a mapping circuit 15 and a demapping circuit 25 in accordance with implementations of the presentdisclosure. Note that the implementations of FIGs. 3, 4 particularly relate to communication based on orthogonal frequency division multiplexing, OFDM.The mapping circuit 15 of FIG. 3 may comprise one or more of: a multiplexing circuit 151, configured to multiplex the discrete-time encoded data x1:N[n] of the parallel analog and digital branches, an Inverse Fast Fourier Transform, IFFT, circuit 152, anda guard time insertion and time windowing circuit 153. This results in a low-pass equivalent of the OFDM symbol of where, ^^is the ^^^ data symbol, which can be the output of analog or digital transmission schemes, ^(^) is the low-passequivalent of the OFDM symbol, ^^ is the number of subcarriers, Δ^ is carrier spacing, and ^ is the OFDM symbol time.The demapping circuit 25 of FIG.4 may comprise one or more of: a guard time removal circuit 253, a Fast Fourier Transform,FFT, circuit 252, and a demultiplexing circuit 251, configured to demultiplex the discrete-time encoded data x1:N[n] of theparallel analog and digital branches.This results in the data symbols in the observed OFDM symbol of where, ^(^Δ^) is the samples of the low-pass equivalent of the observed OFDM symbol at time ^ = ^Δ^, and ^^ is thecorresponding of the ^th data symbol in the observed OFDM symbol, which can be generated by either analog and digital schemes. Note that analog and digital signals may be carried with the same waveform. Therefore, within an OFDM frame, some subcarriers can be allocated to analog modulation and other subcarriers can be allocated to digital modulation. Even within a subcarrier, some OFDM symbols can be allocated to analog modulation and other OFDM symbols can be allocated to digital modulation. The choice of analog or digital transmission depends on the network and users preferences.FIG. 5 illustrates a flow sequence and interaction of methods 4, 5 in accordance with implementations of the present disclosure.Note that although the specific example of FIG. 5 relates to a simple version of a signaling used for uplink data transmissionin a mobile network, it will be appreciated by the skilled person that similar signaling flows and interactions may be deployedin downlink data transmission as well.The method 4 of controlling analog and digital data transmission may be performed by a transmitter device 1 for analog anddigital data transmission, such as a user equipment, UE, and the method 5 of controlling analog and digital data transmissionmay be performed by a controller device 3 for analog and digital data transmission, such as a base station, BS, or 5G base station, gNB.The transmitter device 1 may correspond to any of the implementations illustrated in FIGs. 1 – 3.The method 4 comprises a step of sending 41 a scheduling request to a controller device 3 for analog and digital datatransmission.In other words, the UE sends its scheduling request to indicate to the BS / gNB that it needs some wireless resources for transmission. In general, the coexistence of analog and digital communication doesn’t affect the content of this signal. Correspondingly, the method 5 comprises a step of receiving 51 a scheduling request from a transmitter device 1 for analog and digital data transmission. In other words, the controller device 3 comprises a control circuit 31, is configured to receive a scheduling request from atransmitter device 1 for analog and digital data transmission.The method 5 further comprises a step of allocating 52 communication resources for the transmission.The method 5 further comprises a step of obtaining 53 an estimation of channel state information, CSI, for the communicationresources.The method 5 further comprises a step of selecting 54 a modulation and coding scheme, MCS, indication for the transmissionin accordance with a distortion metric, the communication resources, the CSI, and a source probability density function, PDF,of discrete-time source data u[n].The MCS indication may be indicative of one or more of: a distortion metric, a maximum distortion, the source PDF of thediscrete-time source data u[n], a coding rate, a minimum signal-to-noise ratio, SNR, and a received signal strength indicator,RSSI.The method 5 further comprises a step of sending 55 a control signal for the transmission to the transmitter device 1. Thecontrol signal comprises the communication resources for the transmission; and the MCS indication.That is to say, the control circuit 31 of the controller device 3 is further configured to send a control signal for the transmissionto the transmitter device 1.Correspondingly, the method 4 further comprises a step of receiving 45 a control signal for the transmission from the controllerdevice 3.The control signal, known as download control indicator, DCI, may include scheduling assignments, coding, modulationscheme, and other control information for uplink data transmission (in PUSCH) and / or downlink data transmission (in PDSCH).In the the specific example of FIG. 5 which relates to uplink data transmission, the DCI may be assumed to include schedulingassignments, coding, modulation scheme, and other control information only for uplink data transmission.The decision policy of the gNB for choosing a proper MCS can be based on the application, the channel condition, the available wireless resources, etc. Designing the properties of good MCS set which be efficient, practical, and covers different applications and also the decision policy of choosing an MCS from the set are out of the scope of this invention Note that the transmitter device 1 and the receiver device 2 are further configured to transfer user data as explained in connectionwith FIGs. 1 – 4. The UE thus transmits the data payload according to the specifications in the DCI. The data transmission canbe either modulated in analog and / or digital format based on the specified MCS by DCI.The present disclosure has been described in conjunction with various implementations as examples. However, other variationscan be understood and effected by those persons skilled in the art and practicing the claimed matter, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation. A computer program may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

Claims

CLAIMS1. A transmitter device (1) for analog and digital data transmission, comprisinga control circuit (11), configured to send a scheduling request to a controller device (3) for analog and digital datatransmission, and receive a control signal for the transmission from the controller device (3), the control signal comprising^communication resources for the transmission; and^ a modulation and coding scheme, MCS, indication for the transmission;a sampling and buffering circuit (12), configured to sample discrete-time source data from analog source data, andto buffer the discrete-time source data;amodulation circuit (14), comprising parallel analog and digital branches, respectively configured to modulate thediscrete-time source data to discrete-time encoded data in accordance with the MCS indication; anda mapping circuit (15), configured to map the discrete-time encoded data to a continuous-time transmissionwaveform in accordance with the MCS indication.

2. The transmitter device (1) of claim 1,wherein the analog branch is configured to optimize performance metrics of estimated discrete-time source data decodablefrom the transmission, in accordance with the MCS indication.

3. The transmitter device (1) of claim 1,the MCS indication being indicative of one or more of:^ a distortion metric,^ a maximum distortion,^ a source PDF of the discrete-time source data,^ a coding rate,^ a minimum signal-to-noise ratio, SNR, and^ a received signal strength indicator, RSSI.

4. The transmitter device (1) of claim 3, the analog branch comprisingan analog coding circuit (142), configured to modulate the discrete-time source data to the discrete-time encodeddata such that a loss function of the estimated discrete-time source data is minimized.

5. The transmitter device (1) of claim 4,the loss function being calculated in accordance with one or more of:^ the distortion metric,^ the source PDF,^ an input block length,^ an output block length,^ a channel model, and^ the minimum SNR.

6. The transmitter device (1) of claim 4 or claim 5, the analog branch further comprisinga PDF reshaping circuit (141), configured to convert the discrete-time source data having the source PDF to thediscrete-time source data having a PDF optimized for the transmission.

7. The transmitter device (1) of any one of the claims 4 – 6, further comprisinga source coding circuit (13), configured to convert the discrete-time source data to compressed discrete-time sourcedata.

8. The transmitter device (1) of any one of the claims 4 – 7,wherein the analog coding circuit (142) is configured to maximize an average of a ratio of a Euclidian distance ofeach pair of the discrete-time encoded data and an Euclidian distance of each corresponding pair of the discrete-time sourcedata, such that the loss function of the estimated discrete-time source data is minimized.

9. The transmitter device (1) of any one of the claims 4 – 8, wherein the analog coding circuit (142) comprises a repetition encoder.

10. The transmitter device (1) of any one of the claims 4 – 6, the analog branch further comprisinga joint source channel coding circuit (143), configured to maximize an average of a ratio of a Euclidian distance ofeach pair of the discrete-time encoded data and an Euclidian distance of each corresponding pair of the discrete-time sourcedata, such that the loss function of the estimated discrete-time source data is minimized.

11. The transmitter device (1) of any one of the claims 1 – 10,the mapping circuit (15) comprising one or more of:^ a multiplexing circuit (151), configured to multiplex the discrete-time encoded data of the parallel analog and digital branches,^ an Inverse Fast Fourier Transform, IFFT, circuit (152), and^ a guard time insertion and time windowing circuit (153).

12. A controller device (3) for analog and digital data transmission, comprising acontrol circuit (31), configured to receive a scheduling request from a transmitter device (1) for analog and digitaldata transmission, and send a control signal for the transmission to the transmitter device (1), the control signal comprising^ communication resources for the transmission; and^ a modulation and coding scheme, MCS, indication for the transmission.

13. A receiver device (2) for analog and digital data transmission, comprisinga demapping circuit (25), configured to demap discrete-time encoded data from a continuous-time receptionwaveform in accordance with a modulation and coding scheme, MCS, indication; anda demodulation circuit (24), comprising parallel analog and digital branches, respectively configured to demodulateestimated discrete-time source data from the discrete-time encoded data in accordance with the MCS indication.

14. The receiver device (2) of claim 13,wherein the analog branch is configured to optimize performance metrics of the estimated discrete-time source data inaccordance with the MCS indication.

15. The receiver device (2) of claim 13 or claim 14,the MCS indication being indicative of one or more of:^ a distortion metric,^ a maximum distortion,^ a source PDF of the discrete-time source data,^ a coding rate,^ a minimum signal-to-noise ratio, SNR, and^ a received signal strength indicator, RSSI.

16. The receiver device (2) of claim 15, the analog branch comprising an analog decoding circuit (242), configured to demodulate the estimated discrete-time source data from thediscrete-time encoded data such that a loss function of the estimated discrete-time source data data is minimized.

17. The receiver device (2) of claim 16,the loss function being calculated in accordance with one or more of:^ the distortion metric,^ the source PDF,^ an input block length,^ an output block length,^ a channel model, and^ the minimum SNR.

18. The receiver device (2) of claim 16 or claim 17, the analog branch further comprisinga PDF de-reshaping circuit (241), configured to convert the estimated discrete-time source data having a PDFoptimized for the transmission to the estimated discrete-time source data having the source PDF.

19. The receiver device (2) of any one of the claims 13 – 18, further comprisinga source decoding circuit (23), configured to convert the estimated discrete-time source data to decompressedestimated discrete-time source data.

20. The receiver device (2) of any one of the claims 13 – 19,wherein the analog decoding circuit (242) is configured to determine the estimated discrete-time source data forwhich the distortion of the PDF is minimized, among the set of all possible values of the estimated discrete-time source data.

21. The receiver device (2) of claim 20, wherein the analog decoding circuit (242) comprises a repetition decoder.

22. The receiver device (2) of any one of the claims 13 – 18, the analog branch comprisinga joint source channel decoding circuit (243), configured to determine the estimated discrete-time source data forwhich the distortion of the PDF is minimized, among the set of all possible values of the estimated discrete-time source data.

23. The receiver device (2) of any one of the claims 13 – 22,the demapping circuit (25) comprising one or more of:^ a guard time removal circuit (253),^ a Fast Fourier Transform, FFT, circuit (252), and^ a demultiplexing circuit (251), configured to demultiplex the discrete-time encoded data of the parallel analog anddigital branches.

24. The transmitter device (1) of any one of the claims 1 – 11 or the receiver device (2) of any one of the claims 13 – 22,the distortion metric comprising one of:^ a mean squared error, MSE,^ a mean absolute error, MAE, and^ a symmetric mean absolute percentage error, SMAPE.

25. The transmitter device (1) of any one of the claims 1 – 11 or 24, or the receiver device (2) of any one of the claims 13 –23, the source PDF comprising one of:^ a continuous uniform distribution,^ a Gaussian distribution, and^ an exponential distribution.

26. A method (4) of controlling analog and digital data transmission, comprising^ sending (41) a scheduling request to a controller device (3) for analog and digital data transmission; and^ receiving (45) a control signal for the transmission from the controller device (3), the control signal comprising ^communication resources for the transmission; and^ a modulation and coding scheme, MCS, indication for the transmission.

27. A method (5) of controlling analog and digital data transmission, comprising^ receiving (51) a scheduling request from a transmitter device (1) for analog and digital data transmission;^ allocating (52) communication resources for the transmission;^ obtaining (53) an estimation of channel state information, CSI, for the communication resources;^ selecting (54) a modulation and coding scheme, MCS, indication for the transmission in accordance with a distortionmetric, the communication resources, the CSI, and a source probability density function, PDF, of discrete-time sourcedata;^ sending (55) a control signal for the transmission to the transmitter device (1), the control signal comprising^ the communication resources for the transmission; and^ the MCS indication.

28. The method (4) of claim 26 or the method (5) of claim 27,the MCS indication being indicative of one or more of:^ a distortion metric,^ a maximum distortion,^ the source PDF of the discrete-time source data,^ a coding rate,^ a minimum signal-to-noise ratio, SNR, and^ a received signal strength indicator, RSSI.

29. A computer program, comprising a program code for performing the method (4) of claim 26 or claim 28 or the method(5) of claim 27 or claim 28 when executed on a computer.

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