EP3994857A2

EP3994857A2 - Receiver for receiving a combination signal taking account of inter-symbol interference, method for receiving a combination signal, and computer program

Info

Publication number: EP3994857A2
Application number: EP20737142.8A
Authority: EP
Inventors: Martin HIRSCHBECK
Original assignee: Innovationszentrum fuer Telekommunikationstechnik IZT GmbH
Current assignee: Innovationszentrum fuer Telekommunikationstechnik IZT GmbH
Priority date: 2019-07-03
Filing date: 2020-07-03
Publication date: 2022-05-11
Also published as: DE102019209800B4; US20220123970A1; ZA202201235B; DE102019209800A1; JP2022538914A; WO2021001551A2; CN114731315A; WO2021001551A3; IL289556A; EP4199441A1

Abstract

The invention relates to a receiver for receiving a combination signal which has two separate signal components, of which the pulses are shifted relative to one another and/or of which the carrier oscillations exhibit a phase difference, which receiver is designed to obtain a first series of sampling values using a first sampling, the first sampling being adapted to a symbol phase of the first signal component, and to obtain a second series of sampling values using a second sampling, the second sampling being adapted to a symbol phase of the second signal component. The receiver is designed to obtain probabilities of transmit symbols of the first signal component and probabilities of transmit symbols of the second signal component for a plurality of sampling times based on the second series of sampling values and the first series of sampling values. The receiver is designed to determine probabilities for symbols of the second signal component based on sampling values of the first sampling and estimated or calculated probabilities for symbols of the first signal component taking account of an inter-symbol interference between transmit symbols of the second signal component in the sampling values of the first sampling. The receiver is designed to determine probabilities for symbols of the first signal component based on sampling values of the second sampling and estimated or calculated probabilities for symbols of the second signal component taking account of an inter-symbol interference between transmit symbols of the first signal component in the sampling values of the second sampling.

Description

Receiver for receiving a combination signal taking into account inter-symbol interference, method for receiving a combination signal and computer program

description

Technical area

Embodiments according to the present invention relate to receivers for receiving a combination signal which has two separate signal components whose pulses are shifted from one another and / or whose carrier oscillations have a phase difference.

Further exemplary embodiments according to the invention relate to methods for receiving a combination signal.

Further exemplary embodiments according to the invention relate to corresponding computer programs.

Embodiments according to the invention relate generally speaking to an optimization of a 2-user receiver.

Background of the invention

In the case of digital information transmission, it is often or mostly the case that two or more similar, data-carrying message signals are additively superimposed on the transmission path or are already being emitted as superimposed signals by a transmitter. As long as the transmission side ensures that the signals can be separated by using a multiplex method, e.g. B. by using different frequency ranges (frequency division multiplex or "frequency division multiplex": FDM), disjoint time slots (time division multiplex or "time division multiplex": TDM), different codes (code division multiplex or "code division multiplex access": CDMA) or different spatial directions of propagation and their resolution through several spatially separated receiving antennas (spatial multiplex or "space division multiple access" through MIMO Transmission: SDMA) this poses no problem at all and has been known since the beginning of electrical communications engineering.

The situation becomes more complicated if the signals overlap in an uncoordinated manner at the same time in the same frequency band. As long as the received signals differ significantly in terms of received power, transmission rates (bits per symbol) and / or their power efficiency, successive demodulation, detection and decoding is often possible, i.e. H. a detection of the strongest signal in each case and its subtraction from the received sum signal after re-coding and re-modulation based on the detected data. Under certain boundary conditions, this procedure can even represent an optimal solution in terms of information theory.

It was recognized that in the case of less pronounced differences in the received powers and / or power efficiencies of the individual signals, an iterative procedure can be recommended, with partial subtraction of interfering signals corresponding to the estimated probabilities of the data symbols and the probabilities being expressed in favor of one in each case in several iteration steps Data symbol can be done.

It has been shown that in the case of almost equally powerful and equally efficient signals, usually only the use of an optimal multi-user receiver (or an at least approximately optimal multi-user receiver) is a viable option. The superimposed signals are interpreted as a signal that represents, per modulation step, all data symbols that correspond to the superimposition of the individual signals. In the case of identical modulation methods for N individual signals with M signal elements per modulation step (M-stage transmission method), an equivalent modulation method for the receiving end with up to M ^N signal elements is created, with the same or very similar signal elements for different combinations of the individual data symbols sometimes being unfavorable can. This can cause a drastic loss of capacity.

As an example, an in-phase addition of two BPSK signals (M = N = 2) is given, with the superposition of two constellations {-1; +1} the constellation {-2; 0; +2} arises. A clear inference about the transmission symbols when the reception symbol 0 is detected is no longer possible, even in the case of no interference. If inter-symbol interference (ISI) occurs in individual signals due to dispersive distortions (e.g. as a result of multipath propagation and / or reflections), a signal with up to M ^NL levels is created for optimal multi-user detection, where L denotes the maximum length of the inter-symbol interference, ISI, according to the symbol intervals T. The generation of the received signal can be modulated by the operation of a Mealy automaton with up to (M ^N ) ^{L 1} memory states.

It was recognized that a common optimal detection of all signals by means of a

T rellis decoding method, preferably the Viterbi or BCJR algorithm, which is described, for example, in the book "Trellis Coding: Fundamentals and Applications in Digital Transmission Technology", Vol. 21 of Communication Technology "by J, Huber (Springer-Verlag, 1992 ) is possible.

It was also recognized that the number of memory states is usually so great that real-time implementation of a trellis decoder for optimal multi-user detection is no longer possible.

There is therefore a need for an improved concept for multi-user communication that provides an improved compromise between complexity and reception quality.

An embodiment according to the invention creates a receiver for receiving a combination signal which has two separate signal components whose pulses are shifted from one another and / or whose carrier oscillations have a phase difference.

The receiver has for example (but not necessarily) at least one filter that is adapted to a transmission pulse shape of the pulses of at least one of the signal components.

The receiver is designed to obtain a first series of samples (e.g. y ^ k]) using a first sample, the first sample being adapted to a symbol phase of the first signal component (e.g. synchronized to a symbol phase of the first signal component).

The receiver is designed to obtain a second series of samples (e.g. y [k]) using a second sample, the second sample being sent to a Symbol phase of the second signal component is adapted (for example, synchronized to a symbol phase of the second signal component).

The receiver is designed to measure probabilities (e.g. Pi _{, m} [k]) of transmission symbols of the first signal component and probabilities (e.g. p, m [k]) of transmission symbols of the second signal component for a plurality of sampling times (e.g. k) based on the first Series of samples and the second series of samples.

The receiver is designed to use samples (e.g. y ^ k]) of the first sample (e.g. the sample synchronized to the symbol clock of the first signal component) and estimated or calculated probabilities (e.g. pi _{, m} [k]) for symbols (e.g. m = 0 ... M 1) of the first signal component, taking into account an intersymbol interference (e.g. i _{1 P} ) between transmission symbols of the second signal component in the sample values (e.g. y ^ k]) of the first sample probabilities (e.g. p _{, m} [k]) for To determine symbols (eg m = 0 .., M ₂ -1) of the second signal component.

The receiver is designed to use samples (eg y ₂ [k]) of the second sampling (for example, the sampling synchronized to the symbol clock of the second signal component) and estimated or calculated probabilities eg (p _{2, m} [k]) for symbols (e.g. m = 0 ... M ₂ -1) of the second signal component taking into account intersymbol interference (e.g. i _{2 P} ) between transmission symbols of the first signal component in the sample values (e.g. y ₂ [k]) of the second sample (e.g. updated) To determine probabilities (eg pi _, m [k]) for symbols (eg m = 0 ... M 1) of the first signal component.

The exemplary embodiment of the invention is based on the knowledge that a reception result can be improved by, for example, providing two series of sample values in which, with regard to one of the signal components, an inter-symbol interference through synchronization to a respective symbol phase of the respective signal component is evident is reduced or minimized or eliminated, and in that the inter-symbol interference of the respective other signal component is taken into account when determining the probabilities of the symbols of the respective other signal component.

In other words, by generating two separate series of samples, wherein in the first series of samples inter-symbol interference is reduced or minimized with respect to the first signal component, and where in the second series of samples ! nter-symbol interference is reduced or minimized with regard to the second signal component, on the one hand a “coupling” of the inter-symbol interference of the two signal components can be avoided, which significantly reduces the complexity. On the other hand, both the inter-symbol interference of the first signal component and the inter-symbol interference of the second signal component are taken into account, as a result of which a high reception quality is achieved with at the same time acceptable complexity. In particular, knowledge of the specific properties of the inter-symbol interference of the first signal component in the second series of samples and knowledge of the properties of the inter-symbol interference of the second signal component in the first series of samples when separating the signal components (ie when determining the probabilities of transmission symbols of the first signal component and when determining the probabilities of transmission symbols of the second signal component), which typically results in particularly good reception quality. In other words, the knowledge of the characteristics of inter-symbol interference of the signal components that is typically available at the receiver end can be used efficiently (without excessive complexity) in the separation of the signal components by the receiver by generating two series of samples and by based on the first series of samples using knowledge about properties of an inter-symbol interference between transmission symbols of the second signal component, probabilities for symbols of the second signal component are determined, and based on the second series of samples using a receiver-side knowledge about properties of a Inter-symbol interference between transmission symbols of the first signal component in the sample values, probabilities for symbols of the first signal component can be determined.

The receiver described here thus creates a good compromise between reception quality and complexity, although the complexity per se may be higher than in the case of a receiver which only takes into account inter-symbol interference of one of the signal components.

In one embodiment of the receiver, the sampling times of the first sampling are set (or the receiver is designed to set sampling times of the first sampling - for example by selecting the associated symbol phase - so) that sampling of an output signal of a signal-adapted filter takes place in such a way that an output signal component of the matched filter that is on the first Signal component based, is sampled essentially free of intersymbol interference (for example by sampling with a symbol clock, a symbol phase being selected so that the first signal component is sampled “at the optimal times”, for example ISI-free, or for example in such a way that that sampling times differ by a maximum of 5% or by a maximum of 10 percent of a symbol phase or a symbol duration of zero crossings of a response of the signal-adapted filter to a single transmission symbol of the first signal component).

Sampling times of the second sampling are, for example, set (or the receiver is designed to set sampling times of the second sampling - for example by selecting the associated symbol phase - so) that an output signal of a signal-adapted filter is sampled in such a way that an output signal component of the signal-adapted filter , which is based on the second signal component, is sampled substantially free of intersymbol interference.

By appropriately setting the sampling times of the first sampling and the second sampling, it can be achieved, for example, that it is not necessary to take into account inter-symbol interference between symbols of the first signal component when evaluating the first series of sampling times. Likewise, due to the appropriate selection of the sampling times, it is not necessary to take into account inter-symbol interference between symbols of the second signal component when evaluating the second series of sampling values. In particular, it is also achieved that knowledge of the inter-symbol interference of the first signal component and the second signal component can be used separately, whereas, for example, when using only one series of samples which are neither inter-symbol interference-free with regard to the If the first signal component were scanned without inter-symbol interference with respect to the second signal component, a very high level of complexity would arise, since the inter-symbol interference would then have to be considered in combination.

In addition, the corresponding procedure enables a concept to be adopted with regard to the separation of the two signal components in which the two signal components are processed “equally”. This simplifies the algorithm and also leads to particularly good results. In one embodiment, the receiver is designed to adapt the first sampling to the symbol phase of the first signal component and to the carrier phase of the second signal component (or to synchronize it, for example).

The receiver is also designed to adapt the second sampling to the symbol phase of the second signal component and to the carrier phase of the first signal component (or to synchronize it, for example).

As a result of the design mentioned, it can be achieved that in the first series of samples an inter-symbol interference is reduced with regard to the first signal component or, in the ideal case, is completely suppressed. Furthermore, the corresponding design also ensures that the inter-symbol interference with regard to the second signal component in the second series of samples is significantly reduced or, in the ideal case, is completely suppressed. By adapting the first sampling to the carrier phase of the second signal component and adapting the second sampling to the carrier phase of the first signal component, it can also be achieved that the sampled values are particularly easy to process, for example ideally separated into in-phase components and quadrature -Component.

In one embodiment, the receiver is designed to determine first branch transition probabilities (e.g. r _lk [i, j]) between states of a first state model (for example between memory states of a first time-discrete filter or a hidden Markov model), which is an intersymbol interference between Describes transmission symbols of the second signal component in the sample values of the first sample, based on the sample values (e.g. yi [k]) of the first sample and estimated or calculated probabilities (e.g. Pi _{, m} [k]) for symbols (e.g. m = 0 ... Mi-1) of the first signal component, and based on the first branch transition probabilities (e.g. Y _k [i, j]) probabilities (e.g. p _{2, m} [k]) for symbols (e.g. m = 0 ... M ₂ -1) of the second signal component to be determined.

Alternatively or additionally, the receiver is designed to measure second branch transition probabilities (e.g. Y ₂ , _k l) between states of a second state model (for example between memory states of a time-discrete filter or a hidden Markov model), which is an intersymbol interference between transmission symbols of the first signal component in the sample values of the second sample writes based on the sample values (eg y ₂ [k]) of the second sample and estimated or calculated probabilities (eg p _2, m [k]) for symbols (eg m = 0 ... M ₂ -1) of the second signal component and to determine based on the second branch transition probabilities (eg Y ₂ k [i]) probabilities (eg Pi. _m [k]) for symbols (eg m = 0 ... Mi-1) of the first signal component .

By using the sampled values of the first sampling, in which the inter-symbol interference between transmission symbols of the first signal component is reduced or suppressed, an inter-symbol interference of the second signal component using a state model (which, for example, contains information on a characteristic of the inter- Symbol interference) is evaluated, and by using the second sampling, in which the inter-symbol interference between symbols of the second signal component is reduced or suppressed, inter-symbol interference between transmission symbols of the first signal component using a state model that For example, information about the inter-symbol interference is evaluated, a probability of transmission symbols of the two signal components can for example be determined in a very reliable manner. Information about inter-symbol interference properties of the first signal component as well as about inter-symbol interference properties of the second signal component is used here, with excessive complexity resulting, for example, when both inter-symbol interferences are taken into account at the same time would be avoided by determining two sequences of samples. The available information (in particular the information about inter-symbol interference properties flowing into the state models) can be used to separate the two signal components without the complexity becoming too high.

In one embodiment, the receiver is designed to calculate the probabilities for symbols of the second signal component using a first probability density function (eg to obtain an interference impairing the detection of transmission symbols of the second signal component, wherein the first probability density function a probability (eg Pi _{, m} [k]) of at least one transmission symbol of the first signal component (for example in the form of a weighting) an expected contribution (eg Vi a ₁ at least one transmission symbol of the first signal component to a sample value of the first sampling (for example, taking into account a phase shift between signal components of the first signal and signal components of the second signal), and an expected contribution (e.g. i _{i P} ) of an intersymbol interference between transmission symbols of the second signal component (e.g. a state transition for which a branch transition probability is determined is assigned) (for example in the first sample) is taken into account (the first probability density function being used, for example, to determine the first branch transition probability).

By evaluating, for example, a probability density function that describes a sum of probabilities for different possible transmission symbols of the first signal component, weighted with the respective probabilities, and the simultaneously inter-symbol interference values between transmission symbols of the second signal component for a state transition currently under consideration (e.g. B. i, j), for example, a (local) probability for a state transition of the second signal component (for example a probability that the second signal component has a certain symbol sequence when only one sample is taken into account) can be determined. The available information can thus be taken into account quite comprehensively. On the one hand, probabilities of different possible transmission symbols of the first signal component are taken into account and, on the other hand, inter-symbol interference contributions between transmission symbols of the second signal component for different sampling times of the second signal component can also be taken into account. Thus, overall, by evaluating the probability distribution (which can be contained, for example, from a superposition of different probability density functions), branch transition probabilities can be obtained which can be used, for example, to determine the probabilities of transmission symbols of the second signal component. In one embodiment, the receiver is designed to take into account, when evaluating the first probability density function, a time-variable contribution of a transmission symbol of the first signal component, which results from a difference in carrier frequencies of the first signal component and the second signal component.

Using the appropriate procedure, for example, a deviation in carrier frequencies between the first signal component and the second signal component can be taken into account in an efficient manner. The contribution of transmission symbols of the first signal component can namely be weighted in a time-variable manner by, for example, multiplying it with a time-variable complex pointer. Thus, different signal components can be detected without major problems even if the carrier frequencies differ somewhat.

In one embodiment, the receiver is designed to calculate the probabilities for symbols of the first signal component using a second probability

density function (e.g.) one one

Detection of transmission symbols of the first signal component impairing interference, the second probability density function a probability (e.g. p ₂ m [k]) of at least one transmission symbol of the second signal component (for example in the form of a weighting) an expected contribution (e.g. v ₂ a _{2, m Q} ^{Kf2 f1)} ) at least one ^{transmission symbol of} the second signal component to a sample of the second sampling (for example, taking into account a phase shift between signal components of the first signal and signal components of the second signal), and an expected contribution (e.g. t _{2, p} ) of an intersymbol interference between transmission symbols of the first signal component (for example a state transition for the a branch transition probability is determined) (eg in the second sample) is taken into account (the second probability density function being used, for example, to determine the second branch transition probability).

By obtaining probabilities for symbols of the first signal component, for example, in an analogous manner to the probabilities for symbols of the second signal component, it is possible, for example, to achieve uniformly high reliability in the estimation of symbols of both signal components. The knowledge about the inter-symbol interference can also be used with regard to the determination of both signal components without resulting in excessive complexity.

In one embodiment, the receiver is designed to take into account, when evaluating the second probability density function, a time-variable contribution of a transmission symbol of the second signal component, which results from a difference in carrier frequencies of the first signal component and the second signal component.

With the appropriate procedure, a difference in carrier frequencies of the two signal components can in turn be taken into account in a very simple and efficient manner.

In one embodiment, the receiver is designed to use the first branch transition probabilities (for example y _{l fc} [i ,; ^' ]) (for example using a T rellis decoding method or using the algorithm according to Bahl, Coke, Jelinek and Raviv (BCJR algorithm)) to obtain first state transition probabilities (e.g. Pi _{, k} (ij) and to get probabilities (e.g. p _{2, m} [k]) for symbols (e.g. m = 0 ... M ₂ -1) of the second Signal component using the first state transition probabilities (for example Pi _{, k} (ij)). Alternatively or additionally, the receiver is designed to determine based on the second branch transition probabilities (for example Y ₂ , k [i}) (for example using a T rellis decoding method or using the algorithm according to Bahl, Cocke, Jelinek and Raviv (BCJR algorithm)) second To obtain state transition probabilities (e.g. p _{2 k} (i, j) and to obtain probabilities (e.g. pi _, m [k]) for symbols (e.g. m = 0 ... M 1) of the first signal component using the second state transition probabilities (e.g. p _{2 , k} (i, j)).

By using the appropriate algorithms, the information about the inter-symbol interference between symbols of the first signal component and also the knowledge about the inter-symbol interference between symbols of the second signal component can be used efficiently, with symbol probabilities through the above-mentioned methods or algorithms can be obtained with justifiable complexity.

In one embodiment, the receiver is designed to determine first branch transition probabilities (e.g. y _{l fc} [/ ,; ^' ]) (which are assigned, for example, to a transmission symbol of the second signal component or a state transition from state i to state j based on a transmission symbol of the second signal component are), to be determined based on a sum of probability contributions for different possible transmission symbols (for example m = 0 to M 1) of the first signal component.

The probability contributions are weighted according to the estimated or calculated probabilities ( _e.g. p _{1 tt1} [k] J of the respective (e.g. assigned) transmission symbols of the first signal component and describe a probability that a specified _{transmission symbol of} the second signal component will affect a specified sequence of Transmission symbols of the second signal component (determined for example by the state transition from state i to state j), taking into account a current sample (e.g. yi [k]) of the first sample, an intersymbol interference (e.g. i _1-p ) between transmission symbols of the second signal component and a noise intensity (eg, v _3). Alternatively or additionally, the receiver is arranged to second branch transition probabilities ((eg y _2, s [r /] _f), for example, a transmission symbol of the first signal component and a state transition from the state i are assigned to state j on the basis of a transmission symbol of the first signal component), based on rend to be determined on a sum of probability contributions for different possible transmission symbols (e.g. m = 0 to M ₂ -1) of the second signal component, the probability contributions corresponding to the estimated or calculated probabilities (e.g. p _{2, m} [k]) of the respective (e.g. assigned) transmission symbols of the second signal component are weighted and a probability that a specified transmission symbol of the first signal component is based on a specified sequence of Transmission symbols of the first signal component (determined for example by the state transition from state i to state j) follows, taking into account a current sample (e.g. y ₂ [k]) of the second sample, an intersymbol interference (e.g. i _{2, p} ) between transmission symbols of the first signal component and a noise intensity (e.g. v ₃ ) describe.

With the appropriate procedure, the uncertainty of the respective transmission symbols or the previously determined or estimated probabilities of the respective transmission symbols can be taken into account. Likewise, the inter-symbol interference can be taken into account efficiently in this way, with only the inter-symbol interference between transmission symbols of a signal component being taken into account in each step or partial step. For example, in the context of determining the probabilities of transmission symbols of the second signal component, the previously determined or estimated probability of transmission symbols of the first signal component is taken into account. Furthermore, when determining the probability of a transmission symbol of the second signal component, account is taken of the influence that various sequences of transmission symbols of the second signal component have on a current sample value of the first sample due to the inter-symbol interference. So-called “branch transition probabilities” are thus determined, for example, which are ultimately used to infer the probabilities of transmission symbols of the second signal component. A corresponding concept can also be used for estimating the probabilities of transmission symbols of the first signal component and thus enables an efficient and reliable determination of the probabilities of the transmission symbols of both signal components.

In one embodiment, the receiver is designed to estimate transmission symbols of the second transmission signal component based on a choice of state transitions. The receiver is designed to choose the state transitions so that an overall transition probability based on the branch transition probabilities is maximized. Alternatively or additionally, the receiver is designed to estimate transmit symbols of the first transmit signal component based on a choice of state transitions, the receiver being designed to select the state transitions so that an overall transition probability based on the branch transition probabilities is maximized. Since an overall transition probability is maximized here, transmission symbols of the first signal component and / or the second signal component are reliably estimated or assessed with regard to their probability. By identifying a “best” sequence of state transitions, it is possible to reliably determine the probabilities of transmission symbols of the first signal component and / or the second signal component.

In one embodiment, the receiver is designed to calculate first branch transition probabilities Y _lk [i, j] according to

to get, where m is a running variable, where Mi is a number of constellation points (for example of different possible transmission symbols) of the first signal component, where Pi _{, m} [k] estimated or calculated probabilities of the respective (e.g. assigned) transmission symbols of the first signal component in a Time step k, where yi [k] is a sample of the first sampling at a time step k, where vi is a gain factor of the first signal component, where a _{1 m is} a (for example complex-valued) transmission symbol (for example represented by a constellation point) of the first Signal component with transmission symbol index (or constellation point index) m, or where ai _{, m describes} a time-variable contribution of a transmission symbol of the first signal component with a transmission symbol index m to the sample yj [k], which is due to a difference between a carrier frequency of the first signal component and a carrier frequency of the second signal component results (i.e. for example according to a _{1 m} [k] according to equation (3,10)), where f ₁ -f _{2 describes} a phase shift between transmission symbols of the first signal component and transmission symbols of the second signal component, where i _{1 P is} an intersymbol interference between transmission symbols of the describes the second signal component (which is assigned, for example, to a state transition i, j), and where v _{3 describes} a noise intensity.

Alternatively or additionally, the receiver is designed to measure second branch transition probabilities Y ₂ , _k ] according to where m is a running variable, where M _{2 is} a number of constellation points (for example of different possible transmission symbols) of the second signal component, where p _{2, m} [k] estimated or calculated probabilities of the respective (e.g. assigned) transmission symbols of the second signal component (for example with transmission symbol index m) in a magazine k, where y ₂ [k] is a sample of the second sample for a magazine k, where v _{2 is} a gain factor of the second signal component, where a _2, m is a (e.g. complex-valued) transmission symbol (for example represented by a constellation point) of the second signal component with transmission symbol index (or constellation point index) m, or where a _{2, m describes} a time-variable contribution of a transmission symbol of the first signal component with a transmission symbol index m to the sample value y ₂ [k], which is based on a difference between a carrier frequency of the first signal component and a carrier er frequency of the second signal component (for example, according to a _{2, m} [k] is defined according to equation (3.11)), where <p ₂ -q> i describes a phase shift between transmission symbols of the second signal component and transmission symbols of the first signal component, where i _{2 , p describes} an intersymbol interference between transmission symbols of the first signal component (which is assigned, for example, to a state transition i, j), and where v _{3 describes} a noise intensity.

It was recognized that such a determination of branch transition probabilities is on the one hand very effective and on the other hand leads to reliable results. In particular, it was recognized that the input variables available for calculating the branch transition probabilities can also be determined in a simple manner. For example, the probabilities of the transmission symbols of the respective other signal component can either be estimated in advance or, for example, set to a predetermined starting value at the beginning of an iteration or determined in a previous step as part of an iterative method. The intensity of the respective signal components that flow into the gain factor v can also be estimated, for example, taking into account a total power of the signal and using a comparison of the sampled values of the first sampling and the second sampling. The phase offset between the first signal component and the second signal component is, for example, within the scope of setting the first sampling and the second sampling determinable. The inter-symbol interference between transmission symbols of a signal component can be determined, for example, on the basis of knowledge of the times at which sampling is carried out and, furthermore, on the basis of knowledge of a transmission signal shape of an individual transmission symbol. For example, the inter-symbol interference can be predetermined for various sequences or sequences of transmission symbols as soon as the corresponding sampling times or the phase shifts between the transmission symbols of the two signal components are known. The noise intensity can also be estimated using conventional estimation methods. In this respect, the above-mentioned equations for determining the branch transition probabilities can be evaluated with comparatively moderate effort and take into account the inter-symbol interference in a precise manner.

Thus, using the above formula, a reliable result can be obtained as a whole.

In an exemplary embodiment! the receiver is designed to determine based on the first branch transition probabilities y ₁ to determine probabilities a _{1 k} [i] for a state i in a k-th time step using a forward recursion (for example based on initial probabilities, for example at an initial sampling time of the plurality of sampling times) (for example first forward state probabilities) (where the Probabilities a _{1 k} [i] describe, for example, the probability of a memory state of the discrete filter at a sampling time, starting from an initial sampling time of the plurality of sampling times). The receiver is also designed, based on the first branch transition probabilities y _lk [i, j] using a backward recursion (for example, starting from final probabilities, for example at an end sampling time of the plurality of sampling times) probabilities ßi _{, k + i} Dl for a state j in a k + 1-th journal (for example first backward state probabilities) (where the probabilities ß _{1 k + i} [j] describe, for example, the probability of a memory state of the discrete filter at a sampling time, based on a final sampling time of the plurality of Sampling times). The receiver is further designed to calculate based on the probabilities a _{1 k} [i] for a state i in a k-th journal (for example the first forward state probabilities) and ß _{1 k + 1} [j] for a state j in a k + 1-th journal (e.g. the first backward state probabilities) and using the first branch transition probabilities to determine first state transition probabilities (pi _{, k} (i, j)), and based on the first state transition probabilities (e.g. pi _{, k} (ij)), probabilities (e.g. p _{, m} [k]) of To receive transmission symbols of the second signal component.

Alternatively or additionally, the receiver is designed to calculate probabilities a _{2, k} p] for a state i in a k-th based on the second branch transition probabilities Y _{2 k} [i, j \ using a forward recursion (for example based on initial probabilities) To determine journal (for example second forward state probabilities) (where the probabilities a _{2 k} [i] describe, for example, the probability of a memory state of the discrete filter at a sampling time, based on an initial sampling time of the plurality of sampling times). In this case, the receiver is also designed to calculate probabilities β _{2, k + i} based on the second branch transition probabilities Y ₂ , k, j] using a backward recursion (for example on the basis of end probabilities, for example at an end sampling time of the plurality of sampling times) | j] for a state j in a k + 1-th journal (for example second backward state probabilities) (where the probabilities β _{2, k + i} [j] describe, for example, the probability of a storage state of the discrete filter at a sampling time, ^' starting from a final sampling time of the plurality of sampling times). The receiver is then further designed, based on the probabilities Q _2ik [i] for a state i in a kth journal (for example the second forward state probabilities) and β _{2, k + i} [j] for a state j in a k + 1-th journal (e.g. the second backward state probabilities) and, using the first branch transition probabilities, to determine second state transition probabilities (p _{2 k} (i, j)), and based on the second state transition probabilities to determine probabilities (Pi, _m [k]) of transmission symbols of the first signal component.

By determining the probabilities of the state on the basis of the branch transition probabilities, conclusions can be drawn in an efficient manner about the probabilities of transmission symbols of a signal component under consideration. The use of a forward recursion and a backward recursion can contribute to obtaining the probabilities of transmission symbols of the respective signal component in an efficient and reliable manner. In one embodiment, the receiver is designed to calculate the first state transition probabilities pi _{, k} («j) according to

Pl, fc (hi) ⁼ rans, fc ° h ft [l] 7l, / cj] ^ l, fc + l [/], where C _t rans. _{k is} a normalization factor.

Alternatively or additionally, the receiver is designed to calculate the second state transition probabilities p _{2 k} (i, j) according to where c _tran s _{, k is} a normalization _factor .

By means of the calculation mentioned, the access transition probabilities can be calculated in a simple manner based on the state probabilities and the branch transition probabilities.

In one embodiment, the receiver is designed to obtain probabilities (eg p _2, m [k]) of transmission symbols of the second signal component for a plurality of sampling times (eg k) based on the first series of sampling values (eg y ^ k]) and taking into account intersymbol interference (e.g. i _{1 P} ) between transmission symbols of the second signal component in the first series of samples by using a first instance of a BCJR method, and overlays (e.g. v ₁ a _{1 m} e ^{i (<p1 <p2)} ) to be taken into account as interference by transmission symbols of the first signal component.

The receiver is also designed to obtain probabilities (eg pi _{, m} [k]) of transmission symbols of the first signal component for a plurality of sampling times (eg k) based on the second series of samples (eg y ₂ [k]) and thereby Intersymbol interference (e.g. i _{2 P} ) between transmission symbols of the first signal component in the second series of samples by using a second instance of a BCJR method (which is carried out separately from the first instance of the BCJR method, for example), and overlays (e.g. n _{232 P1Q} ^{Kf2 "f1)} ) to be taken into account as disturbances by sending symbols of the second signal component. It has been shown that by using two instances of the BCJR method, which are carried out separately from one another or carried out one after the other, or carried out in an iterative or alternating manner, the probabilities of the transmission symbols of the two signal components more efficiently and can reliably determine. By taking into account superimpositions of transmission symbols of the respective other signal component as interference, for example inter-symbol interference with regard to the transmission symbols of the respective other signal component is not taken into account, the algorithm can be very efficient and excessive complexity can be avoided will. Thus, within the scope of an instance of the BCJR method, only inter-symbol interference of a signal component under consideration is dealt with, while an overlay of the transmission symbols of the other signal component only flows in as “interference” without taking into account inter-symbol interference in this regard. The concept described here represents a very good compromise in terms of complexity and reliability.

In one embodiment, the receiver is designed to measure transmission symbols on which the first signal component is based or probabilities of transmission symbols on which the first signal component is based by means of a trellis decoding method or based on the algorithm according to Bahl, Cocke, Jelinek and Raviv (BCJR Algorithm).

The receiver is also designed to use a trellis decoding method or based on the algorithm according to Bahl, Cocke, Jelinek and Raviv (BCJR algorithm) to determine transmission symbols on which the second signal component is based, or probabilities of transmission symbols on which the second signal component is based ) to be determined.

By determining transmission symbols or probabilities of transmission symbols by means of a trellis decoding method or an algorithm according to Bahl, Cocke, Jelinek and Raviv, the inter-symbol interference in one of the signal components can be taken into account efficiently. In particular, through the use of the algorithms mentioned, the recipient's knowledge of the inter-symbol interference can also be used, which leads to improved reliability of the estimated transmission symbols or estimated probabilities of transmission symbols. One embodiment creates a method for receiving a combination signal which has two separate signal components, the pulses of which are shifted from one another and / or the carrier oscillations of which have a phase difference.

The method includes obtaining a first series of samples (yi [k]) using a first sample, the first sample being adapted to a symbol phase of the first signal component (e.g., synchronized to a symbol phase of the first signal component).

The method comprises obtaining a second series of samples (y ₂ [k]) using a second sample, the second sample being adapted to a symbol phase of the second signal component (e.g. synchronized to a symbol phase of the second signal component).

The method comprises obtaining probabilities (eg pi _{, m} [k]) of transmission symbols of the first signal component and of probabilities (eg p _2, m [k]) of transmission symbols of the second signal component for a plurality of sampling times (eg k) based on the first series of sampled values and the second series of sampled values, based on sampled values (e.g. yi [k]) of the first sampling (i.e. the sampling synchronized to the symbol clock of the first signal component) and estimated or calculated probabilities (e.g. Pi _{, m} [k ]) for symbols (eg m = 0 ... M 1) of the first signal component taking into account an intersymbol interference (eg i _{1 P} ) between transmission symbols of the second signal component in the sample values (eg y ^ k]) of the first sample probabilities (eg p _{2, m} [k]) can be determined for symbols (eg m = 0 ... M ₂ -1) of the second signal component, and based on sampling values (eg y ₂ [k]) of the second sampling (that is to say that of the symbol clock the second Signal component synchronized sampling) and estimated or calculated probabilities (e.g. p _{2 m} [k]) for symbols (e.g. m = 0 ... M ₂ -1) of the second signal component taking into account an intersymbol interference (e.g. i _{2, p} ) between transmission symbols of the first signal component in the sample values (e.g. y ₂ [k]> of the second sample (e.g. updated) probabilities (e.g. Pi _, m [k]) for symbols (e.g. m = 0 ... M 1) of the first signal component can be determined.

The corresponding method is based on the same considerations as the device described above. The method can also be characterized by all features, functionalities and details are added which are also described herein with regard to the devices according to the invention, both individually and in combination.

Another exemplary embodiment creates a computer program with a program code for carrying out the method when the program runs on a computer. The computer program is based on the same considerations as the corresponding method and can also be supplemented by all features, functionalities and details described herein, both individually and in combination.

Brief description of the figure

Exemplary embodiments according to the present invention are explained in more detail below with reference to the accompanying figures.

Show it:

1 shows a block diagram of a receiver according to an embodiment of the present invention;

2a, 2b show a flowchart of a concept for determining probabilities of transmission symbols of two signal components, according to an exemplary embodiment of the present invention;

3 shows a block diagram of a receiver according to a further exemplary embodiment of the present invention;

4a, 4b show a flowchart of a concept for determining probabilities for symbols of two signal components, according to an exemplary embodiment of the present invention;

5 shows a flow chart of a method according to an exemplary embodiment of the present invention;

6 shows a flow chart of a method according to an exemplary embodiment of the present invention; 7a, 7b show a schematic representation of two different 2-user receiver concepts.

Detailed description of the execution examples

1. Recipient according to Fiq. 1

1 shows a block diagram of a receiver in accordance with an exemplary embodiment of the present invention. The receiver according to FIG. 1 is designated by 100 in its entirety.

The receiver 100 is designed to receive a combination signal 110 and, based thereon, to deliver information 112 about probabilities for symbols of the second signal component and information 114 about probabilities for symbols of the first signal component.

It is assumed, for example, that the combination signal 110 has two separate signal components whose pulses are shifted from one another and / or whose carrier oscillation has a phase difference. The two signal components contained in the combination signal 110 can originate, for example, from different transmitters that transmit, for example, simultaneously, that is to say without the use of time division multiplex or frequency division multiplex or code division multiplex, in the same or overlapping frequency range.

The receiver 100 optionally includes a filter 130 which is adapted to a transmission pulse shape, which for example receives the combination signal 110 and delivers a filtered version 132 of the combination signal 110. The filter 130 can, however, also be omitted, so that the combination signal 110 takes the place of the filtered version 132 of the combination signal.

The receiver 100 further comprises a sample value determination or sample value determiner 140, which is designed to obtain a first series 142 of sample values using a first sample, the first sample being connected to a symbol phase of the first signal component is adapted. The sampling value determination or sampling value determiner 140 is also designed to obtain a second series 144 of sampling values using a second sampling, the second sampling being adapted to a symbol phase of the second signal component. For this purpose, the sample determiner 140 receives, for example, the combination signal 110 or the filtered version 132 of the combination signal. However, the sample determiner 140 could optionally also receive a further preprocessed version of the combination signal 110. Such an optional preprocessing can include, for example, filtering or frequency conversion, or any other type of preprocessing that is typically used in a receiver front end.

In this regard, it should be noted that an input signal of the sample value determination 140 or sample value determiner 140 (which can include, for example, two analog / digital converters operating in a time offset, whose sampling times are set or adjusted accordingly) contain, for example, two superimposed signal components that are shifted in time to one another of which, for example, a first signal component can be scanned in a first time pattern without inter-symbol interference, and of which, for example, a second signal component can be scanned in a second time pattern that is shifted in time compared to the first time pattern, without inter-symbol interference is scannable. For example, a signal shape of the first signal component belonging to a transmission symbol can have a maximum at a point in time t = 0 and then zero at times T, 2T, 3T. The first signal component can consist, for example, of corresponding signal forms shifted by T in each case. It can be seen here that at times T, 2T, 3T, etc., only a portion of a single transmission symbol of the first signal portion contributes to the sample.

In a similar way, for example, a signal shape of the second signal component belonging to a transmission symbol can have a maximum at a point in time ti and can have zeros at points in time t-i + T, h + 21, + 3T. If the second signal component is sampled at times t-i, h + T, ti + 2T, h + 3T, etc., then corresponding sampled values each include only a contribution from a single transmission symbol of the second signal component.

If one now assumes that the first signal component and the second signal component, for example, many transmission symbols of the first signal component (offset in time by integer multiples of T) and many transmission symbols of the second signal component (in each case also offset in time by integer multiples) in the input signal of the sample value determination 140 from T, but offset in time to the transmission symbols of the first signal component), are contained in a superimposed form, it can be seen that a composite signal is difficult to separate. It will also be seen that, for example, when scanning for

Time t = 0 (or at times t = k · T) a sample value, for example, has a contribution from only a single transmission symbol of the first signal component but contributions from several transmission symbols of the second signal component. In a similar way, a sample that is sampled at the time ti (or at the times t = + kT) has only a contribution from a single transmission symbol of the second signal component, but also contributions from several transmission symbols of the first signal component (inter-symbol Interference).

The sampling value determination 140 is thus designed to obtain a first series 142 of sampling values using a first sampling, the first sampling being adapted to a symbol phase of the first signal component. The first sampling takes place, for example, at times t = 0 + k · T, so that the first signal component is sampled at least essentially free of inter-symbol interference, and so that the second signal component is sampled with intersymbols (so that for example one of the sampled values has only a single transmit symbol of the first signal component (essential or non-negligible) influence, and so that several transmit symbols of the second signal component have a (substantial or non-negligible) influence on the sampled value).

The sampling value determination 140 is also designed, for example, to obtain a second series 144 of sampling values using a second sampling, the second sampling being adapted to a symbol phase of the second signal component.

For example, the second sampling can take place at times t = ti + k * T (where k is a natural number). In this way, for example, the second signal component is sampled at least essentially free of inter-symbol interference, while, on the other hand, the first signal component is sampled with inter-symbol interference. For example, a sampled value is influenced (or significantly influenced) by a single transmission symbol of the second signal component but by several transmission symbols of the first signal component.

It should be pointed out, however, that the first sampling and the second sampling do not necessarily have to take place in an ideal manner. Rather, tolerances with regard to the sampling times are possible, which can amount to +/- 5% or +/- 10% or +/- 20% of a sampling period T, for example. With this, for example For example, the first sampling should be at least approximately free of inter-symbol interference with regard to the first signal component, while a (non-negligible) inter-symbol interference is present with regard to the second signal component. For example, the inter-symbol interference in the sampling with regard to the first signal component can be negligible, for example to the extent that the inter-symbol interference with regard to the first sampling value is less than 5% or less than 10% or is less than 20% of a signal value caused by a current transmission symbol. The same can also apply with regard to the second sampling.

In addition, it should be pointed out that corresponding sampling times can be set or regulated, for example, by analyzing the combination signal 110. In this case, for example, a phase shift, which is referred to below as tpi-cp ₂ or <p- <pi, can also be determined.

The receiver 100 further comprises a first probability determination or a first probability determiner 150 which is designed to receive the first series 142 of sample values and, based thereon, to obtain probabilities 112 for symbols of the second signal component. The receiver 100 further comprises a second probability determination or a second probability determiner 160 which is designed to receive the second series 144 of sample values and, based thereon, to determine probabilities 114 for symbols of the first signal component. Overall, the receiver is thus designed to obtain probabilities of transmission symbols of the first signal component and probabilities of transmission symbols of the second signal component for a plurality of sampling times (for example denoted by k) based on the first series 142 of sampled values and the second series 144 of sampled values.

The first probability determination 150 is designed, for example, based on sample values of the first sample, i.e. based on sample values of the first series 142 of sample values, and estimated or calculated probabilities for symbols of the first signal component, taking into account an inter-symbol interference between transmission symbols of the second signal component to determine the probabilities 112 for symbols of the second signal component in the sample values of the first sample (or the first series 142 of sample values). Furthermore, the second probability determination 160 is designed, for example, to determine based on sample values of the second sample (i.e. based on the sample values of the second series 144 of sample values) and estimated or calculated probabilities for symbols of the second signal component, taking into account an inter-symbol interference between transmission symbols of the first signal component in the sampling values of the second sampling (that is to say in the sampling values of the second series 144 of sampling values) to determine probabilities 114 for symbols of the first signal component.

For example, the first probability determination can receive information about probabilities for symbols or transmission symbols of the first signal component in various ways. The probabilities of the symbols or transmission symbols of the first signal component can be formed, for example, by default values, e.g. B. at the beginning of an evaluation, if no additional information is available on the recipient side. The probabilities of the symbols or transmission symbols of the first signal component can, however, also be supplied by the second probability determination 160 if this has already been carried out, for example, when the first probability determination is taking place. Similarly, the information about probabilities for symbols or transmission symbols of the second signal component used by the second probability determination 160 can be based on predefined values or initial values or on probabilities for symbols or transmission symbols of the second signal component 112 determined by the first probability determination 150.

In other words, the probabilities used by the probability determinations 150, 160 for symbols of the respective other signal component can either be specified - for example as initial values - or be determined by another device or can also be determined in the respective other probability determination. In particular, it is also possible to carry out the method iteratively in order to alternately improve the probabilities for symbols or transmission symbols of the signal components.

In summary is thus to be noted that 100 two series 142, 144 are produced by samples in a Abtastwertbestimmung in the receiver, wherein a first scanning in which the first series is obtained 142 samples, is so provided a _¬ that the first signal part Inter-Symbol-Interference-Free or Inter-Symbol- Interference-poor is sampled, and wherein a second sampling, in which the second series 144 of samples is obtained, is set so that the second series 144 of samples with respect to the second signal component inter-symbol interference-free or Inter -Symbo-interference-poor is obtained. Based on this, probabilities 112 for symbols or transmission symbols of the second signal component are then determined as part of the first probability determination 150, both assumed or previously determined probabilities for transmission symbols of the first signal component and information about the inter-symbol interference between the symbols of the second signal component be taken into account. For example, on the basis of knowledge of the sampling times of the first sampling and the second sampling or on the basis of knowledge of the time shift between the transmission symbol clock of the first signal component and the transmission symbol clock of the second signal component and, for example, also based on knowledge of the transmission symbol signal shapes of the first signal component and of the second signal component (which are typically known to the receiver 100), which inter-symbol interference result in certain (different) sequences of transmission symbols of the second signal component in the first series of samples and which inter-symbol interference certain (different) Sequences of transmission symbols of the first signal component in a sample of the second series 144 of samples result. The knowledge of the inter-symbol interference properties of the first signal component and the second signal component can therefore be used both in the first probability determination 150 and in the second probability determination 160 in order to determine the probabilities 112, 114 for the symbols or transmission symbols of the second signal portion or the first signal component with particularly high reliability. By the above-explained suitable selection of the sampling times of the first sampling or the second sampling, it is also achieved that in the first probability determination 150 consideration of an inter-symbol interference between transmission symbols of the first signal component can be disregarded, and that in the second probability determination 160, consideration of the inter-symbol interference between transmission symbols of the second signal component can be disregarded. In this way, complexity is kept within manageable limits.

In addition, it should be pointed out that the receiver 100 can be supplemented by all features, functionalities and details that are still described below. The corresponding features, functionalities and details can be included in the receiver 100 both individually and in combination. 2 Concept according to Figures 2a and 2b

2a and 2b show a flow chart of a concept for determining probabilities for symbols or transmission symbols of two signal components. The concept according to FIGS. 2a and 2b are designated by 200 in their entirety.

It should also be noted that the concept 200 according to FIGS. 2a and 2b can be implemented by the receiver 100, for example. For example, the essential processing steps of the concept 200 can be carried out by the first probability determination 150 and the second probability determination 160. The sampling values y _t [k] and y ₂ [k] used in the course of the processing can be obtained, for example, by the sampling value determiner 140.

The processing steps are explained in more detail below.

A first processing section 210 comprises a determination of a probability 252 of a symbol of the second signal component based on a probability 292 of a symbol or transmission symbol of the first signal component or based on probabilities of a plurality of symbols or transmission symbols of the first signal component. Naturally, probabilities of a plurality of symbols or transmission symbols of the second signal component can also be determined in the first processing section 210.

It should be pointed out in particular that the first processing section uses, for example, a sample value 212 (also referred to as y ^ k]) of the first series 142 of sample values. In addition, assumed or previously determined probabilities of symbols or transmission symbols of the first signal component (for example at a point in time with time index k) flow into the first processing section 210. The probabilities can be assumed, for example, as an initial value, or can be determined, for example, within the framework of the second processing section 260.

Information 214 about an intensity of the first signal component (also designated by V _t ) flows into the first processing section 210. Furthermore, information 216 about a transmission symbol of the first signal component or a plurality of transmission symbols (for example with index m) of the first also flows into the first processing section 210 Signal component (also referred to as ai _{, m} ). In other words, the information 216 about transmission symbols of the first signal component describes, for example in the form of a complex value, an (expected) contribution of an mth transmission symbol of the first signal component to the current sample y ^ k] of the first series of samples, with earlier sampling times or transmit symbols of the first signal component belonging to later sampling times are not taken into account, since a small or negligible inter-symbol interference between transmit symbols of the first signal component in the first series of samples is assumed. The first processing section 210 also uses information about a phase shift between transmission symbols of the first signal component and transmission symbols of the second signal component, which is designated, for example, by 218 or fi-f ₂ . The first processing section 210 also uses information about an inter-symbol interference between transmission symbols of the second signal component in the sample values of the first series 212 of sample values (yi [kj). The information 219 about the inter-symbol interference is also denoted by ii _{, p} [ij]. The information 219 about the inter-symbol interference between transmission symbols of the second signal component can, for example, for different sequences of transmission symbols of the second signal component on the basis of the signal shape of a transmission symbol typically known to the receiver and on the basis of the phase position of the transmission symbols of the second signal component with regard to the sampling times of the first Sampling can be calculated. For example, all sequences of transmission symbols of the second signal component that have an impact on the current sample value y -, [k] can be taken into account. Thus, for example, the information 219 can describe what contribution to the sample yi [k] different sequences of transmission symbols of the second signal component due to the inter-symbol interference (i.e. the superposition of transmission signal forms of transmission symbols of the second signal component that occur at different times be sent). The different sequences of transmission symbols of the second signal component are described, for example, by the indices i and j, where i and j can be understood as states in a state machine that describes the generation of the sequences of transmission symbols of the second signal component. In this respect, the transition from a state i to a state j can be understood as a state transition which, for example, characterizes a sequence of transmission symbols of the second signal component.

Overall, it should be noted that the inter-symbol interference values i _{1 ip} [ij] on the part of the receiver based on knowledge of the transmission signal shape or reception signal shape of transmission symbols of the second signal component and based on knowledge of the sampling times can be determined (and, for example, does not have to be calculated for each iteration step or for the reception of each individual transmission symbol, but rather only has to be determined once as soon as the sampling times are known more closely, or can even be provided in a predetermined manner in a value table or a memory area) .

The first method section 210 comprises calculating 220 branch transition probabilities, e.g. B. Yi, _k [i, j], which can be done using equation (2.3), for example. Thus, the computation 220 provides branch transition probabilities, e.g., Yi. _k pj] · For example, the branch transition probabilities can be calculated for various combinations of the indices or state indices i and j. For example, a (current) sample value yi [k] of the first series of sample values can flow into the calculation 220. Furthermore, the previously estimated or determined probabilities pi _{, m} [k] of the symbols of the first signal component (for example for the sampling time k) can be taken into account in the calculation 220. Furthermore, the intensity v _{1 of} the first signal component, the (for example complex-valued) transmission symbols of the first signal component a ₁ that are typically known to the receiver, the phase shift between the first sampling and the second sampling that is typically known to the receiver and the inter-symbol that can also be determined by the receiver Interference between transmission symbols of the second signal component can be taken into account in the calculation 220. Furthermore, the calculation 220 can also take into account a noise intensity that can be determined by the receiver or a signal-to-noise ratio that can be determined by the receiver. For details with regard to a possible procedure, reference is made, for example, to the explanations below on equation (2.3).

The calculation 220 thus calculates branch transition probabilities, e.g. B.

Yi. _k pj], which can be used in a calculation 230 of state probabilities (e.g. ai, _k p] and βi, _{k + i} [j]. The calculation 230 of state probabilities can, for example, using a method with a Forward recursion and a backward recursion can take place, it being possible to start from previously determined or assumed start and end probabilities. For example, a so-called BCJR method, which is familiar to the person skilled in the art, can be used for this purpose. Alternatively, other T rellis decoding methods can also be used are also familiar to the person skilled in the art. Thus, for example, state probabilities for journal k, e.g. B. a _{1 k} [i] and also state probabilities for a journal k + 1, e.g. B. ßi, _{k + i} [j] obtained, for example, together with the branch transition probabilities z. B. Yi. _k Pj] in a determination 240 of the first state probabilities, e.g. B. pi _k pj] can be used. This determination of the state transition probabilities pi _k [ij], which can be made for different combinations of i and j, for example, or which can even be made for all meaningful combinations of i and j, for example, can be made using equation (2.4), which is described below will be explained.

The state transition probabilities p _ik [i J] can be used, for example, in a probability determination 250 in order to determine probabilities of symbols or transmission symbols of the second signal component at time k (e.g. p _{2, m} [k]). For this purpose, for example, the values of Pi. _K Dj] can be suitably added up.

In summary, it should be stated that in the first method section 210 probabilities of a symbol of the second signal component or probabilities of different symbols of the second signal component or probabilities of all possible symbols of the second signal component based on a (current) sample of the first series of samples and also based on assumed or previously determined probabilities of symbols of the first signal component can be determined. A consciously accepted inter-symbol interference between transmission symbols of the second signal component is used efficiently, for example, by calculating branch transition probabilities, deriving state probabilities and determining state transition probabilities, with a Reliis decoding method or BCJR method can be used to take into account the inter-symbol interference between the transmission symbols of the second signal component in an efficient manner.

The second method section 260 functions in a similar manner, in this case based on assumed or previously determined probabilities of symbols or transmission symbols of the second signal component (e.g. p _2rtT1 [k]) and using a sample of the second series of samples (e.g. B. y ₂ [k]) probabilities of symbols or transmission symbols of the first signal component can be determined. As can be seen from FIG. 2b, the second method section 260 comprises calculating 270 of Branch transition probabilities (e.g., Y ₂ , _k [i, j]). The calculation 270 of branch transition probabilities can take place, for example, in accordance with equation (3.2), which is described below. In the calculation 270 of branch transition probabilities, for example a (current) sample value y ₂ [k] of the second series of sample values can be taken into account. Furthermore, in the calculation 270, probabilities of symbols or transmission symbols of the second signal component (for example p _2, m [k]) can be taken into account. Furthermore, an intensity of the second signal component (v ₂ ) determined by the receiver (which can be defined absolutely or relatively, for example in relation to an intensity of the first signal component, or in relation to noise) can be taken into account in the calculation 270. Furthermore, in the calculation 270 of branch transition probabilities, knowledge of the transmission symbols or the reception symbols (for example in the form of a complex-valued representation) on the part of the receiver is typically taken into account (for example denoted by a ₂ , _m ). Furthermore, the calculation 270 preferably takes into account a phase shift between the first sampling and the second sampling. Furthermore, the calculation 270 takes into account information about inter-symbol interference between transmission symbols of the first signal component in the sample values of the second series of sample values. Information about the inter-symbot interference (z. B. i ₂ , _p [i, j]) can for example be provided by the receiver on the basis of knowledge of a transmission signal shape or reception signal shape of the transmission symbols of the first signal component as well as on the basis of a Knowledge of the sampling phase of the second sampling can be obtained. It can thus be determined by the receiver, for example, which contribution different sequences (for example defined by i and j) of transmission symbols ^{' of} the first signal component make to the (current) sample y ₂ [k] of the second series of samples. The receiver can in particular take into account that several transmission symbols of the first signal component make a significant (non-negligible) contribution to the sample y ₂ [k], since the second series of sample values is not inter-symbol with regard to the transmission symbols of the first signal component -Interference-free is sampled. On the other hand, when calculating branch transition probabilities, it can in particular be assumed that only one transmission symbol of the second signal component makes a significant contribution to the current sample value y ₂ [k], while, for example, 270 contributions from other (e.g. earlier or transmitted later) transmission symbols of the second signal component for the sample y ₂ [k] can be neglected. Correspondingly, branch transition probabilities (e.g. Y2, _k [ij]) can be obtained through the calculation 270, which are included in a calculation 280 of state probabilities (e.g. a ₂ , _k [i]) and β ₂ , _{k + i} ü]) are included. By means of the calculation 280, for example, state probabilities for the time step k (e.g. a _2lk [i]) and state probabilities for the time step k + 1 (e.g. β ₂ , _{k + i} [j]) receive. The state probabilities for journal k and the state probabilities for journal k + 1 can then be used together with the branch transition probability in a determination 290 of state transition probabilities (for example p _{2 k} [i, j]) will.

This determination 290 of the first state transition probability chains 292 can take place, for example, using equation (3.3), which is explained below. The state transition probabilities p _{2, k} [ij] for different state transitions from state i to state j can thus be obtained.

The state transition probabilities 291 can then be used in a probability determination 294 in order, for example, to calculate probabilities of symbols of the first signal component 292 (for example Pi _{, m} [k]). The determination of the probabilities of the symbols of the first signal component can be done, for example, by a suitable summation of state transition _{probabilities} p _2rk [i JD, whereby, for example, the state transition probabilities of those states that belong to a certain _{transmission symbol} ( _e.g. ai _{, m} ) can be summed up.

In summary, it should be noted that calculation 270 essentially corresponds to calculation 220, that calculation 280 essentially corresponds to calculation 230, that determination 290 essentially corresponds to determination 240, and that probability determination 294 essentially corresponds to probability determination 250, where sizes adapted to the corresponding signal component are used.

Furthermore, with regard to the concept 200, it should be noted that the concept can begin, for example, with the first method section 210 or with the second method section 260, the respective other method section being carried out subsequently. The method can also take place iteratively, with the two method sections 210, 260 being carried out, for example, several times in succession and alternately. In this way, an iterative improvement in the determination or estimation of the probabilities of the symbols of the two signal components can take place. For example, the probability of transmission symbols of the first signal component determined in probability determination 294 can be used as input variable in calculation 220, and the probabilities of transmission symbols of the second signal portion obtained in probability determination 250 can be used as input variable in calculation 270.

Incidentally, further details with regard to the concept 200 will be described later. In particular, reference is made to the statements on formulas (2.3), (2.4), (3.2) and (3.3) as well as the other accompanying explanations.

It should also be noted that the concept 200 according to FIG. 2 can be supplemented by all features, functionalities and details that are described herein, both individually and in combination.

3. Receiver according to FIG. 3

3 shows a block diagram of a receiver 300 according to an exemplary embodiment of the present invention.

The receiver 300 is designed to receive a combination signal 310 which, for example, has a first signal component and a second signal component. The receiver 300 is further designed to obtain probabilities 312 for symbols of the first signal component and to obtain probabilities 314 for symbols of the second signal component. The receiver 300 optionally comprises a filter 330 which is adapted to a transmission pulse shape and which, for example, receives the combination signal 110 and delivers a filtered signal 332. The filter 330 may, for example, correspond to the filter 130 of the receiver 100, and the filtered signal 332 may, for example, correspond to the filtered signal 132. The remaining statements with regard to the possible preprocessing of the combination signal 110, which were explained with regard to the receiver 100, otherwise apply accordingly to the receiver 300.

The receiver 300 further comprises a sampling value determination 340, which corresponds, for example, to the sampling value determination 140 of the receiver 100. The sample value determination or sample value determiner 340 supplies, for example, a first series 342 of sample values (for example y ^ k]) and a second series 344 of sample values (y ₂ [k]). The first Series 342 of sample values corresponds, for example, to the first series 142 of sample values, and the second series 344 of sample values corresponds, for example, to the second series 144 of sample values, so that the above statements made with regard to the series 142, 144 of sample values also apply be valid.

In summary, it should be noted that the receiver 300 is designed to receive a combination signal 310 which has two separate signal components whose pulses are shifted from one another and / or whose carrier oscillation has a phase difference. The receiver 300 has, for example (but not necessarily) a filter adapted to a transmission pulse shape of the pulses of at least one of the signal components. The receiver is also designed to obtain a first series 342 of sample values using a first sample, for example by sample value determination 340, the first sample being adapted to a symbol phase of the first signal component (for example being synchronized to a symbol phase of the first signal component). The receiver is also designed to obtain a second series 344 of sampled values using a second sampling, for example by sampling value determination 340, the second sampling being adapted to a symbol phase of the second signal component (for example being synchronized to a symbol phase of the second signal component).

The receiver 300 further comprises a first probability determination 350, which is designed, based on sample values of the first sample (or the first series 342 of sample values) and estimated or calculated probabilities for symbols of the second signal component without taking into account (or neglecting) a Inter-symbol interference between transmission symbols of the first signal component in the sample values of the first sample to determine probabilities for symbols of the first signal component. The receiver further comprises a second probability determination 360, which is designed to determine based on sample values of the second sample (or the second series 344 of sample values) and estimated or calculated probabilities for symbols of the first signal component without taking into account an inter-symbol interference between transmission symbols of the second signal component in the sample values of the second sample to determine (for example updated) probabilities for symbols of the second signal component. The receiver is thus designed overall to measure probabilities 312 of the transmission symbols of the first signal component and probabilities 314 of the transmission symbols of the second signal component for a plurality of sampling To obtain times based on the first series 342 of samples and the second series 344 of samples.

With regard to the functionality of the receiver 300, it should be pointed out that probabilities for symbols or transmission symbols of the second signal component, which are based, for example, on an assumption or were previously determined, are taken into account when determining the probabilities 312 for symbols of the first signal component. It is thus taken into account, for example, what contribution or interference contribution transmit symbols of the second signal component have to a (current) sample (e.g. yi [kj) of the first series of samples (or have with a certain probability), if the probabilities for the symbols or transmission symbols of the first signal component are determined. The influence of several transmission symbols of the second signal component sent one after the other is also taken into account, since these typically all have an influence on a current sample of the first series of samples. However, since the transmission symbols of the second signal component are only taken into account as “interference” or “interference contribution” when determining probabilities for symbols of the first signal component, and since, furthermore, based on the first sampling, it is assumed that in the first series 342 of samples none or there is no significant inter-symbol interference between symbols of the first signal component, the probability determination 350 can be carried out with comparatively little complexity.

The situation is similar for the probability determination 360. Since, when determining the probabilities for symbols of the second signal component, the symbols of the first signal component are only regarded as an interference or as an interference contribution to the current sample value (e.g. y ₂ [k]), and Since in the probability determination 360 it is also assumed that there is no or no substantial inter-symbol interference between transmission symbols of the second signal component in the second series 344 of samples, the complexity of the probability determination 360 is comparatively low.

In addition, it should be noted that in the probability determination 350, i.e. in determining the probabilities of the symbols of the first signal component, estimated or previously calculated probabilities for symbols of the second signal component flow in a similar way in the probability determination 360, i.e. in determining the probabilities for symbols of the second signal component, estimated or previously determined probabilities for symbols of the first th signal component. The probability determination 350 and the probability determination 360 can also be carried out one after the other or iteratively alternately so that the corresponding probabilities for symbols of the two signal components are each improved. In a first iteration step, for example, assumed probabilities can be used, while in the following iteration steps previously determined probabilities can be used.

In summary, it should be stated that the receiver 300 can determine the probabilities for symbols of the two signal components in a particularly efficient manner. By obtaining two series 342, 344 of sample values in the sample determination 340, and by obtaining the probability for symbols of the first signal component based on the first series of samples which are sampled adapted to the symbol phase of the first signal component, and by the probabilities for symbols of the second signal component are obtained based on the second series of samples which are sampled adapted to the symbol phase of the second signal component, the probabilities for the symbols of the two signal components can be obtained in a very efficient manner. Although inter-symbol interference is preferably not evaluated step-by-step here, but merely taken into account as an interfering contribution to the sampled values, it has been shown that in many situations, reliable estimated values for the probabilities of the symbols of the signal components can still be achieved with little effort can be obtained.

Further optional details are also explained below.

In particular, the receiver 300 can optionally be supplemented by all features, functionalities and details that are described herein, both individually and in combination.

4. Concept according to FIGS. 4a and 4b

4a and 4b show a flowchart of a concept for determining probabilities for symbols of a first signal component and of probabilities for symbols of a second signal component based on sample values of a combination signal or a preprocessed (e.g. filtered in a signal-adapted manner) combination. onssignals. The concept according to FIGS. 4a and 4b is designated by 400 in its entirety.

The concept 400 comprises a first method section 410 and a second method section 460.

In the first method section 410, based on assumed or previously determined probabilities 492 for symbols of a first signal component (e.g. Pi _, m [k]) and also based on a (current) sample of the second series of samples (e.g. y ₂ [k]) probabilities 432 are determined for symbols of the second signal component (for example p _{2, m} [k]).

Concept 400 further includes a second method section 460 in which, for example, based on (assumed or previously determined) probabilities for symbols of the second signal component (e.g. p _{2, m} [k]) and also on a (current) sample of the first A series of sample values (for example yi [k]> probabilities 492 for symbols of the first signal component (for example Pi _{, m} [k]) can be determined.

In this regard, it should be pointed out that, depending on the circumstances, first the first method section 410 and then the second method section 460 can be carried out. Alternatively, the second method section 460 and then the first method section 410 can also be executed first. Furthermore, the first method section 410 and the second method section 460 can be executed alternately, for example, in order to B. to iteratively improve the probabilities for symbols of the first signal component and the second signal component belonging to a point in time (for example “k”). It is fundamentally irrelevant whether both process sections 410, 460 are run through with the same frequency here, or whether one process section is run through more often than the other.

The first section of the procedure is discussed below. The corresponding statements also apply in a corresponding manner with regard to the second procedural stage.

The first method section 410 includes, for example, a determination 420 of probabilities of different sequences p (where p is an index of the sequences) of transmission desymbolen the first signal component. For example, the probability Pr {i ₂ [k] = i _{2, p} } can be determined. The corresponding probability describes, for example, the probability that the sequence p of transmission symbols of the first signal component is present, which generates an interference value i _{2, p} in the sample value y ₂ [k] of the second series of sample values. For this purpose, it is determined, for example on the basis of the knowledge of the transmission signal shape or the reception signal shape, which originates from transmission symbols of the first signal component, which sequence of transmission symbols of the first signal component or which sequence of transmission symbols of the first signal component an (interference) contribution i _{2, P} for the sample y ₂ [k] delivers. The probability of the corresponding sequence of transmission symbols of the first signal component is then determined, or, for example, probabilities of several sequences of transmission symbols of the first signal component, all of which lead to the (interference) contribution i _{2 P} , are added up. If, for example, only one sequence (from a plurality of possible sequences or from a total set of possible sequences) of transmission symbols of the first signal component leads to the (interference) contribution i _{2 P} , the probability of this sequence of transmission symbols of the first signal component can easily are calculated based on the probabilities for transmission symbols of the first signal component (492), for example according to equation (3.6). In other words, if the receiver determines that a certain sequence of transmission symbols of the first signal component leads to the (interference) contribution i _{2 P} to the sample y ₂ [k], then the probability of this sequence of transmission symbols of the first signal component be determined for example by multiplying the probabilities of the transmission symbols of the first signal component belonging to the sequence in question. If, on the other hand, several different sequences of transmission symbols of the first signal component lead to the same or a very similar (interference) contribution to the sample y ₂ [k], then the probabilities of these individual sequences can in turn be multiplied by the probabilities of the transmission symbols belonging to the respective sequences are obtained, and the probabilities for the respective consequences can then be added up in order to obtain an overall probability for the respective (disturbance) contribution i _2rP .

In addition, it can also be determined how many different (interference) contributions i _{2, p} there are, which depends on the signal constellation and also on the length of the inter-symbol interference of the transmission symbols of the first signal component or the temporal expansion of the transmission signal curve or The received signal curve that belongs to the transmit symbols of the first signal component can depend. The number of M ^ ^{dec + 1} given in equation (3.4) should be understood here as an example. It should also be noted that that different sequences of transmission symbols can lead to the same or a very similar (interference) contribution i _{2 P} , so that these sequences can be combined or “clustered”, for example.

In summary, it should be noted that in step 420, for example, the probabilities of different sequences of transmission symbols of the first signal component can be determined, or alternatively also the probabilities of different values of an (interference) contribution i _{2 P.} If a different (interference) contribution i _{2rP is} supplied for each sequence of _{transmission symbols} , the two calculations are identical. On the other hand, if the same or almost the same (interference) contributions i _{2, p are} achieved through different sequences of transmission symbols of the first signal component, the number of different (interference) contributions i _{2 P can be} smaller than the number of different sequences of transmission symbols of the first signal component.

In summary, it should be noted that step 420 both a determination of probabilities of different sequences p of transmission symbols of the first signal component and, alternatively, a determination of probabilities of different (interference) contributions i _{2, P} (which differ based on the different sequences of transmission symbols of the first signal component) may include. Thus, in step 420, for example, a probability of different sequences p of transmission symbols of the first signal component or a probability of different (interference) contributions i _{2, p is} obtained.

The first method section 410 also includes a calculation 430 of probabilities for symbols of the second signal component (for example p _{2, m} [k]). The calculation can be done using equation (3.4), for example. In this regard, it should be noted that the summation shown in equation (3.4) can take place, for example, over all different sequences p of transmission symbols of the first signal component (which contribute to an (interference) contribution i _{2, p} F 0) (in which case the Probabilities of the various consequences p are taken into account). The summation can alternatively take place over all different (interference) contributions i _{2, p} , in which case, for example, the probability that a corresponding (interference) contribution i _{2 P is} generated by the transmission symbols of the first signal component can be taken into account.

It should also be pointed out that when calculating 430 probabilities for symbols of the second signal component, a (current) sample (e.g. y ₂ [k]) of the two th series of samples can be taken into account. Furthermore, for example an intensity 422 (for example v ₂ ) of the second signal component, which can be estimated or determined by the receiver, can be taken into account. The intensity v _{2 of} the second signal component can, for example, be determined absolutely or also relatively (for example in relation to the first signal component or in relation to noise, for example in the form of a signal-to-noise ratio). Furthermore, the calculation 430 typically takes into account (e.g. complex-valued) transmission symbols of the second signal component (e.g. a _{2, m} ) known to the receiver. Furthermore, in the calculation 430 interference from the sequences p of transmission symbols of the first signal component (e.g. i _{2 P} ; also referred to as “(interference) contribution of transmission symbols of the first signal component to the sample y ₂ [k]” ) considered.

As mentioned, the calculation 430 of probabilities for symbols of the second signal component can take place, for example, using equation (3.4). An intensity of the noise (e.g. v ₃ ) or a signal-to-noise ratio can also be taken into account here. Overall, for example, it is determined within the scope of the calculation how probable the various symbols of the second signal component are, with partial probabilities, for example, being added up assuming various (interference) contributions i _2rP . For example, it is checked how likely a transmission symbol a _{2, m is} in view of the sample y ₂ [k], the interference i _{2 P} , the intensity of the second signal component (e.g. v ₂ ) and the intensity of the noise (e.g. B. v ₃ ), assuming a Gaussian distribution of the noise, for example.

The probabilities 232 determined in step 430 for symbols of the second signal component (for example p _{2, m} [k]) can then be output, for example, or can also be used in the second method section 460.

The second method section 460 runs essentially parallel to the first method section 410, so that the above statements - adapted accordingly - also apply.

In the second method section 460, based on probabilities 432 for symbols of the second signal component (e.g. p _{2, m} [k]) and also based on a (current elapsed) sample (z. B. y ^ k]) of the first series of sample probabilities 492 for symbols of the first signal component (z. B. Pi _{, m} [k]) is determined.

The second method section 460 includes a determination 470 of probabilities of different sequences of transmission symbols of the second signal component (for example Pr {h [k] = ii p}), which can for example take place based on the information 432 about probabilities for symbols of the second signal component . Equivalent to the determination of probabilities of different sequences of transmission symbols of the second signal component, a determination of probabilities of different (interference) contributions of the second signal component (e.g. i _{1 ip} ) to the current sample y ^ k] can also be determined. In this regard, the statements made above regarding provision 420 apply in a corresponding manner. For example, the determination 470 can take place using equation (2.7) or using an equation corresponding to equation (2.7) and adapted to the respective symbol sequence. In other words, probabilities of transmission symbols of the second signal component that belong to a sequence of transmission symbols of the second signal component that is currently under consideration can be multiplied. Optionally, probabilities of different sequences of transmission symbols of the second signal component, which lead to the same (interference) contribution i _{1 ip} , can be added up if, for example, the probabilities of different (interference) contributions are to be determined.

The determination 470 thus determines, for example, probabilities 472 of different sequences of transmission symbols of the second signal component or probabilities of different (interference) contributions i _{1 ip} .

The second method section 460 further comprises calculating 480 probabilities for symbols of the first signal component (for example p _{1 m} [k]). This calculation 480 can be done using equation (2.5), for example. A current sampling value yi [k] of the first series of sampling values can, for example, flow into the calculation of the probabilities for symbols of the first signal component. Furthermore, the probabilities of different sequences of transmission symbols of the second signal component determined in step 470 or the probabilities of different (interference) contributions h, _p determined in step 470 can be taken into account in the calculation 480 of probabilities for symbols of the first signal component. Furthermore, information 482 about an intensity of the first signal component (e.g. vi) can also flow into the calculation 480, the information 482 about the intensity of the first signal component, for example can be determined absolutely or relatively (e.g. in relation to the second signal component or in relation to noise) by the receiver. Furthermore, information known to the receiver about the transmission symbols of the first signal component (a _{1 m} ), which is also denoted by 484, typically flows into the calculation 480. The information 484 can, for example, describe which (for example complex) sample value the various transmission symbols of the first signal component (with index m) in the absence of inter-symbol interference between transmission symbols of the first signal component, in the absence of the (interference) contribution ί ₁ and in the absence of noise (as well as in the absence of other disturbances). In other words, the information 484 describes the ideal transmission symbols or the reception symbols produced in the ideal case by the various transmission symbols. Furthermore, the calculation 480 takes into account the interference (or the (interference) contribution) i _{1 ip} , which results from the various sequences p of transmission symbols of the second signal component. The corresponding contribution is also labeled 486. Furthermore, an intensity 488 of the noise, which can be determined, for example, by the receiver, is also taken into account in the calculation 480.

Thus, in the calculation 480, overall probabilities for transmission symbols of the first signal component (for example Pi _{, m} [k]) are obtained, which are also designated 492. The probabilities 492 can be output, for example, or can be used or reused in the first method section 410 for the determination 420.

As already mentioned with regard to the calculation 420, in the calculation 480 it can be determined, for example, how likely it is, given the current sample y ^ k] of the first series of samples, that a specific transmission symbol (with index m) will occur in a time step k was sent if the interference i _{1 ip} due to various possible sequences p of transmission symbols of the second signal component and an intensity of the noise and also an estimated intensity of the first signal component are taken into account, but inter-symbol interference between transmission symbols of the first signal component is not taken into account.

In summary, it should be noted that with the concept 400, both probabilities for transmission symbols of the first signal component and probabilities for transmission symbols of the second signal component can be determined in a very efficient manner. An efficient determination is realized by taking two series of samples and by not considering details of inter-symbol interference.

Further explanations can be found below.

The concept 400 according to FIG. 4 can optionally be supplemented by all features, functionalities and details that are described herein. In particular, the formulas described below can be used to carry out the various method steps. Alternatively, modified formulas can be used that achieve the corresponding functionality. Furthermore, it should be pointed out that the concept 400 can be supplemented by the features, functionalities and details described herein both individually and in combination.

5. The method according to FIG. 5

5 shows a flow diagram of a method 500 for receiving a combination signal which has two separate signal components, the pulses of which are shifted from one another and / or the carrier oscillations of which have a phase difference.

The method includes obtaining 510 a first series of samples using a first sample, the first sample being adapted to a symbol phase of the first signal component.

The method further includes obtaining 520 a second series of samples using a second sample, the second sample being adapted to a symbol phase of the second signal component. The scans can be carried out, for example, in parallel or one after the other. Obtaining 510 the first series of sample values and obtaining 520 the second series of sample values can take place, for example, in parallel or one after the other.

The method 500 further comprises obtaining 530 probabilities of transmission symbols of the first signal component and of probabilities of transmission symbols of the second signal component for a plurality of sampling times based on the first series of sampling values and the second series of sampling values. Obtaining 530 probabilities can include determining probabilities, for example for symbols of the second signal component based on sample values of the first sample and estimated or calculated probabilities for symbols of the first signal component taking into account an inter-symbol interference between transmission symbols of the second signal component in the sample values of the first sample. Obtaining 530 probabilities can furthermore be based on determining probabilities of the symbols of the first signal component based on sample values of the second sample and estimated or calculated probabilities for symbols of the second signal component taking into account an inter-symbol interference between transmission symbols of the first signal component in the sample values of the second Include scanning.

The method 500 can optionally be supplemented by all the features, functionalities and details that are described herein, both individually and in combination. In particular, the method 500 can also be supplemented by all the features, functionalities and details that are described herein with regard to the devices according to the invention.

6. Method according to FIG. 6

6 shows a flow chart of a method 600 for receiving a combination signal which has two separate signal components, the pulses of which are shifted from one another and / or the carrier oscillation of which has a phase difference. The method includes obtaining 610 a first series of samples using a first sample, the first sample being adapted to a symbol phase of the first signal component. The method 600 further comprises obtaining 620 a second series of samples using a second sample, the second sample being adapted to a symbol phase of the second signal component. Obtaining 610 the first series of samples and obtaining 620 the second series of samples can be carried out, for example, in parallel or in succession.

The method 600 further comprises obtaining 630 probabilities of transmission symbols of the first signal component and of probabilities of transmission symbols of the second signal component for a plurality of sampling times based on the first series of sample values and the second series of sample values. Obtaining 630 probabilities includes, for example, determining probabilities for symbols of the first signal component based on sample values of the first sample and estimated or calculated probabilities for symbols of the second signal component. nal component without taking into account an inter-symbol interference between transmission symbols of the first signal component in the sample values of the first sample. Obtaining 630 of probabilities further comprises determining probabilities for symbols of the second signal component based on sample values of the second sample and estimated or calculated probabilities for symbols of the first signal component without taking into account an inter-symbol interference between transmission symbols of the second signal component in the sample values of the second Scanning.

The method 600 can be supplemented by all the features, details and functionalities that are described herein, both individually and in combination. In particular, the method 600 can also be supplemented by all the features, functionalities and details that are described herein with regard to the devices according to the invention.

7. Further exemplary embodiments

Further exemplary embodiments are described below. In particular, a technical environment and a background are explained. In addition, an iterative separation is described according to the non-prepublished German patent applications 10 2018 202 648 and 10 2018 202 649 (references [1] and [2]). Receiver concepts for an optimized 2-user receiver are described. An initial situation and preprocessing are discussed. Iterative separation using a modified BCJR algorithm is also described. In this regard, a first step (step 1) and a second step (step 2) are described, for example.

Furthermore, suggestions for extensions or changes according to aspects of the invention are explained. Thus an expansion or change to a double inter-symbol interference utilization (ISI utilization) is described. Furthermore, an expansion or change to a twofold, complexity-reduced processing without BCJR is described. Furthermore, an expansion or change to mutually different carrier frequencies is described.

Some exemplary embodiments are also presented.

7.1. Technical environment and background With regard to the technical environment, reference is made, for example, to the not previously published German patent applications 10 2018 202 847, 10 2018 202 648 and 10 2018 202 649.

7.2. Iterative separation according to the non-prepublished German patent applications 10 2018 202 648 and 10 2018 202 649 (references Hl and G21).

7.2.1 Receiver concepts for optimized two-user reception

Receiver concepts for an optimized two-user receiver that can be used in exemplary embodiments according to the present invention, for example in a modified form, are described below.

7a shows a schematic representation of a receiver with an integration of the channel decoding into the separation method. The receiver according to FIG. 7a is designated by 700 in its entirety. The receiver 700 receives a received signal 710 which, for example, has a first signal (signal 1) and a second signal (signal 2) or a first signal component and a second signal component.

The receiver 700 includes a received signal converter 720 which is designed, for example, to convert the received signal 710 into a frequency, for example into an intermediate frequency range or into a baseband. The conversion 720 may, for example, generate a complex-valued output signal with an in-phase component and a quadrature component. An output signal of the converter 720 is denoted by 722.

The receiver 700 further includes a synchronization 730 which can, for example, analyze the received signal 710 or the converted received signal 722 and, for example, can determine one or more parameters of the received signal or the converted signal 722. For example, the synchronization 730 can determine a carrier frequency, a carrier phase, a symbol duration or a symbol phase and, for example, control a sampling or a plurality of samplings accordingly or synchronize them to the received signal 710 or the converted received signal 722. The receiver 700 further comprises a separation with decoding 740. The separation and decoding can include, for example, decoded data 742 of the first signal (e.g. signal 1) or of the first signal component and decoded data 744 of the second signal (e.g. signal 2 ) or the second signal component on the basis of the received signal or the converted received signal 722 or on the basis of sample values based on the received signal 710 or the converted received signal 722.

Further details are explained below.

7b shows a schematic representation of a receiver with separate channel decoding for each signal after the separation. The receiver according to FIG. 7b is designated by 750 in its entirety. The receiver 750 is designed to receive a received signal 760 which, for example, corresponds to the received signal 710. The receiver 750 further comprises a conversion 770, which corresponds, for example, to the conversion 720 of the receiver 700. The receiver 750 further comprises a synchronization 780 which corresponds, for example, to the synchronization 730 of the receiver 700. The receiver 750 further comprises a separation 790 which is designed to receive, for example, a first signal (for example signal 1) or a first signal component 792 and a second signal (for example signal 2) or a second signal component 794, for example The separator 790 can obtain the first signal 792 and the second signal 794 on the basis of the received signal or the converted received signal 772 or on the basis of samples based on the received signal 760 or on the converted received signal 772.

The receiver 750 further comprises a first decoding device 796 which is designed, for example, to obtain first decoded data 794 based on the first signal ^' 792. The receiver 750 further comprises a second decoding device 798 which is designed to obtain second decoded data 797 based on the second signal or signal component 794.

Further details are explained below.

In summary, it should be noted that FIGS. 7a and 7b describe two receiver concepts for a two-user receiver. In both receiver concepts, a multicarrier signal (e.g. the received signal 710 or 760) is converted into the equivalent complex baseband after reception (block conversion 720, 770 in FIGS 7b) and the parameters or modulation parameters (e.g. carrier frequency and / or carrier phase and / or symbol duration and / or symbol phase and / or modulation method and / or signal power) are estimated (e.g. in block “synchronization” 730 , 780). In the processing afterwards, the concepts differ from one another.

In the first concept according to FIG. 7a, channel decoding takes place in the separation process (for example in the block “separation with decoding” 740 in FIG. 7a). The decoded data 742, 744 of the two signals or signal components are present at the output separately from one another.

In the second concept according to FIG. 7b, the channel coding is not used for the separation process, so that after separation (block “separation” 790) from the reliability information of the channel bits (for example the first signal 792 and the second signal 794) by means of channel decoding (e.g. B. by the first decoding 796 and the second decoding 798) the decoded data are calculated. The channel coding method used at the transmitter should (or must in some cases) be known.

An iterative process is proposed as the separation process, which is described in the following sections.

In summary, it can therefore be said that the functionalities or function blocks as shown in FIGS. 7a and 7b can be included, for example, in the receivers 100 and 300 according to FIGS. 1 and 3 individually or in combination. For example, the implementation 720, 770 can be used in the context of preprocessing in the receivers 100, 300. The synchronization 730, 780 can also be used in the receivers 100, 300 and can, for example, suitably control the sample value determination 140, 340 or synchronize it to a transmission symbol clock or to a transmission symbol phase. Furthermore, the probability determinations 150, 160 can, for example, correspond to the separation 790 (or also the separation 740). Alternatively, for example, probability determinations 350, 360 can correspond to separation 790 (or also separation 740). It should also be noted that the concepts described herein for determining the probabilities of transmission symbols of two signal components, for example can be used within the framework of the separation 740 and / or within the framework of the separation 790.

For example, the concept 200 according to FIG. 2 can be used in the context of the separation 740 and in the context of the separation 790. As an alternative to this, the concept 400 according to FIG. 4 can also be used in the context of the separation 740 or in the context of the separation 790.

In other words, the receiver concepts that are described with reference to FIGS. 7a and 7b can optionally be supplemented by all of the features, functionalities and details that are described herein, both individually and in combination. In particular, the concepts described below for determining the probabilities of transmission symbols or for signal separation in the receivers 700, 750 can also be used.

7.2.2 Starting point

Some conditions that should be met in exemplary embodiments of the invention are described below.

The following conditions are assumed: two signals which overlap in the frequency range and are continuously transmitted in the observation time frame are received. These signals or signal components are contained, for example, in the combination signal 110 or the combination signal 310 or in the received signal 710 or in the received signal 760.

Both signals (or signal components) use digital pulse amplitude modulation (RAM), which means amplitude-shift-keying (ASK), phase-shift-keying (PSK) and quadrature-amplitude-modulation (quadrature-amplitude-modulation , QAM) as well as all mixed forms and differential precoding. For the pulse shaping, the transmitter side, as is common practice, root Nyquist

Pulses (square root Nyquist pulses) such as B. root-raised cosine, RRC pulses

(Root-raised cosine pulses) are used.

Symbol rates and carrier frequencies of both signals (or signal components) are approximately identical.

It should now be pointed out that the stated conditions do not necessarily have to be met. Rather, one or more or all of the above conditions can be deviated from in some cases.

7.2.3 Preprocessing

A possible preprocessing that can be used, for example, in the case of starting examples according to the present invention is described below. For example, the received signal is first converted into the equivalent complex baseband. This can take place, for example, within the framework of preprocessing in the receivers 100 or 300, or within the framework of the implementation 720 or the implementation 770. For example, the signal with the estimated carrier frequency is shifted into the baseband.

After estimating the symbol rate, the signal passes through a signal-matched filter or “matched filter” (ie matching the transmission filter for maximum noise limitation) and it is sampled at the symbol rate. The filtering can take place, for example, by the filter 130 adapted to the transmission pulse shape or by the filter 330 adapted to the transmission pulse shape, and the sampling can take place, for example, by the sampling value determination 140 or the sampling value determination 340. The estimation of the symbol rate can take place, for example, by the synchronization 730 or the synchronization 780, and the filtering and sampling can take place, for example, as part of the separation 740 or the separation 790.

The symbol phase is chosen so that a signal, hereinafter referred to as signal 1 (or first signal, or first signal component), is sampled at the optimal times, ie is free of inter-symbol interference (ISI). In this case, signal 2 (or the second signal, or the second signal component) is usually not sampled for the correct point in time, so that inter-symbol interference (ISI) occurs. In addition, the signal is for example synchronized with the estimated carrier phase of signal 2. For example, the following discrete-time signal y ^ k] is present at the synchronization output in time step k:

2.1) with the following quantities: a fc] e {a _{1> 0} , a _{1 1} , ... and a ₂ [k] e {a _{2 0} , a _{2 1} , ..., a, _M2-1 } ^: symbols _carrying data, where Mi and M represent the number of constellation points of signal 1 and 2.

^{Z /} 1 ' ^{V2, 1 /} : Gain factors of signal 1, 2 and of the additive, white, Gaussian noise

Total pulse shape from transmit and receive filter, as well as transmission channel yL, Y2

: Carrier phases of signals 1 and 2

Symbol phases, i.e. time shift to the optimal sampling times of signal 1 and 2

^P1 ^ additive, white, Gaussian noise with variance 1

For example, index 1 stands for the first processing part, with the second processing part only being introduced in the extension in Section 7.3.1.

7.2.4 _ Iterative separation using a modified BCJR algorithm

The two symbol sequences a fc] and a ₂ [k] can be detected, for example, with the aid of a Viterbi algorithm. The number of states is for example where L _{dec represents} the number of ISI taps or ISI taps taken into account. Between the states, there are M _t × M ₂ Upper transitions, so the complexity of higher-level modulation tion process increases sharply. The number of states increases if a common trellis decoder method is used when using convolutional codes as the channel code in order to increase the power efficiency.

To reduce the enormous effort due to the high number of states, an iterative method can be used, for example, in which the two symbol sequences are detected separately in each iteration step and the other signal is included in the detection as a disturbance becomes. For this purpose, for example, the a posteriori probabilities for the symbols a _a [k] and a ₂ [k] are calculated iteratively, with all probabilities being assumed to be identical in the first step, for example. A modified BCJR algorithm is used in each iteration, which is described in Section 7.2.4.1, where BCJR stands for Bahl, Cocke, Jelinek and Raviv and represents an algorithm for trellis decoding. Before that, a couple of definitions are introduced. The approximated ISI value i ₂ [k] of signal 2 present in time step k, which acts as interference on signal 1, is described by, for example

Note: The index 1 at [k] relates to the processing path 1 in y ^ [k] There is, for example, Af2 ^{dec + 1} , possible values for i ^ k]. After the synchronization parameters are available, these hypothetical values can be calculated and are given the designation / _{1 ip} with the index pe - l}.

The a posteriori probability that a / c] = a _{1> m was} sent is denoted by p _lm [k] and, equivalent to this, p _{2> m} [k] is the a posteriori probability that a ₂ [k ] = a _{2 m was} sent,

The BJCR algorithm works in blocks, ie a certain number of symbols is first collected as a block before the a posteriori probabilities of the transmission symbols are iteratively estimated on this block. Since the magazine k in (2.2) requires L _dec / 2 symbols before and after k, the block size must be increased by L _dec / 2. The added symbols themselves are not re-estimated. Equally probable values are assumed as a posteriori probabilities of the symbols that have not yet been estimated. When the estimation of the symbols of a block is finished, the temporally following block is processed, the blocks overlapping in time so that the following block already has estimated values for its a posteriori probabilities for its first symbols (at least L _dec / 2).

In other words, knowing the symbol phases Ti and T ₂ as well as the total pulse shaping g ₀ (T) and the constellation points that are assigned to different data-carrying symbols, the receiver can use the values h [k] or i _{i P} for different possible Determine sequences of data symbols or transmission symbols of the second signal component. The symbol phases T- _t and T ₂ can for example be determined by the receiver by analyzing the received signals of the synchronization. The total pulse g ₀ (t) can also be known for the receiver 750, since the receiver typically knows the predetermined transmit and receive filters and can make an estimate of the channel properties. It is thus easily possible to determine i _{1 P} or i _{2 P,} for example. Other approaches for the determination of i _{1 P} are of course also possible.

7.2.4.1 Step 1

In step 1, an estimate of the a posteriori probabilities for signal 2 from the a posteriori probabilities of signal 1 is carried out with the aid of the modified BCJR algorithm. When the trellis is run through, the BCJR first uses non-normalized branch transition probabilities y _lk [i, j] in the k th journal from state / to state j by means

calculated, where / _{1 ip} corresponds to the ISI value belonging to the branch. Note: The index 1 at Y _{1> k} [i, j] refers to the processing path 1 in y fc]. Thereafter, the calculated values y _{1 fc} [j] for all k, i, j are used to perform the forward and backward recursion. In the forward recursion, the probability a _lk [i] for a state i in the k th journal is calculated by including the state probabilities up to journal k − 1. In the case of backward recursion, the probability β _lk [i] for a state i in the k-th journal is calculated by including the probabilities of the subsequent states up to journal k.

The state transition _probability p _lk [i ,;] can now be estimated by

Pl, fc (U) = Ctrans «l, fc [Yl.k Wl.k + l lJ]

(2.4) where C _tran s. _K is to be chosen so that the sum of the probabilities in each journal equals 1.

The a posteriori probabilities p ₂ , _m [] can now be determined by adding up the state transition probabilities p _lk , j] which belong to the respective symbol a ₂ m.

7.2.4.2 Step 2

In step 2, the a posteriori probabilities for signal 1 are estimated from the a posteriori probabilities of signal 2 by adding the individual probabilities of all possible ISI points.

The a posteriori probabilities p _lm [/ c] for signal 1 are determined as follows:

where the a priori probabilities Pr ^ [k] = i _{l P} } are calculated from the product of the L _dec + 1 a posteriori probabilities p ₂ , _m [k] belonging to i _{l P.} For example, the sequence of symbols belongs to the interference value p = 0

so the value for Pi ^ i fc] = i _{1 0} } is calculated by

Pr {[k] = / i, o} = Pißl ^. _ec / 2] · p ₂ k ^. £ _dec / 2 + 1] · -p ₂ d ^{k +} ec l

(2.7)

In addition, c _{l Sbs} is chosen so that the sum of all a posteriori probabilities p _{l Tn} [k] equals 1.

7.3 _... Suggestions for extensions

In the following, expansions or modifications of the concept described in section 7.2 according to the exemplary embodiment of the present invention are described. The concepts described herein can also be used in connection with the concepts described in section 7.2 in exemplary embodiments according to the present invention.

In particular, embodiments according to the invention can be obtained by modifying the arrangements described in Section 7.2 based on the concepts according to Sections 7.3.1 and / or 7.3.2 and / or 7.3.3.

7.3.1 Extension to double utilization

An idea according to one aspect of this invention is an extension of the BCJR method (e.g. according to Section 7.2.4) to include additional preprocessing, which means that the detection of the ISI component using BCJR can be used twice, so that the ISI memory both signals can be used. In addition to y _t [k], the following signal is calculated: (or assumed or obtained by sampling):

A second processing is thus added, the symbol phase of signal 2 and, for example, the carrier phase of signal 1 now being synchronized. The noise component n ₂ [k] is strongly correlated with n fe]. This is not exploited in further processing, but can optionally be done for a further improvement in the performance efficiency.

The separation now takes place exactly as described in Sect. 7.2.4, but in step 2, instead of applying equation (2.5), a second instance of the BCJR algorithm is applied to the detection of the ISI states of signal 1, with the two Indices that stand for the signals are swapped. The equations (2.3) and (2.4) thus become

and

P2, k (L /) - ^c trans, k ^ 2, k [f] / 2, / V-> j ß2, k + l [/]

(3.3)

In other words, the sequence y ₂ [k] can be obtained, for example by a second sampling, which can be described, for example, by equation (3.1) with a suitable setting of the sampling. Based on the signal y ₂ [k], which can correspond, for example, to the second series 144 of sampled values or the second series 344 of sampled values, the probability determiner 160 using the formulas (3.2) and (3.3) and using a Summing up the probabilities obtained by the formula (3.3) on probabilities Pi, m [k] for symbols of the first signal component can be concluded. For example, A BCJR algorithm can be used to calculate the probability values a _{2, k} [i] and ßa based on the values g ₂ , k [ϊ J] obtained in equations (3.2). _{get k + i} Dl.

However, alternative approaches are also possible.

7.3.2 Extension (or modification) to double, reduced-complexity processing without BCJ R

A further modification of the procedure described above (for example in Section 7.2) according to one aspect of the present invention is described below.

As an alternative to double ISI utilization, as described in Section 7.3.1, the additional processing by means of (3.1) (or the second sampling that delivers a signal according to (3.1)) can also be used iteratively to process the symbols of both signals , but without taking advantage of ISI memory, to save computational complexity. The saving in computational complexity comes at the expense of the power efficiency, which describes the signal-to-interference power ratio necessary to achieve a certain symbol error rate. This loss of power efficiency decreases with a low symbol phase difference and a favorable carrier phase difference between signal 1 and 2, so that there are situations in which the separation by using ISI memory does not have better power efficiency - with higher computing complexity.

The estimation of the a posteriori probabilities p _{l tn} [k] for signal 1 takes place, for example, according to the steps described in Section 7.2.4.2 according to (2.5) - (2.7). For the estimation of the a posteriori probabilities p _{2> m} [/ c] for signal 2, the processing using y ₂ [k] from (3.1) is equivalent:

where the a priori probabilities Pr {i ₂ [k] =, for example, are calculated from the product of the for example L _dec + 1 a posteriori probabilities pi, _m {k] which belong to i ₂ , _p . For example, the sequence of symbols belongs to the interference value p = 0

for example, the value for Prfi ₂ [fc] = i _2fi } is calculated by

In addition, c _{2 Sbs} is chosen such that the sum of all a posteriori probabilities p _{2, m} [fc] equals 1.

In other words, both when determining the probabilities of transmission symbols of the first signal component and when determining probabilities for transmission symbols of the second signal component, a concept can be used in which the probabilities of transmission symbols of the other signal component are used to determine probabilities of different ones (Interfering) contributions (e.g. i _{1 ip} or i _{2, p} ) can be used. In addition, taking into account the (interfering) contributions, the probability of the various transmission symbols is determined, with partial probabilities for the individual transmission symbols that result from the presence of certain (interfering) contributions via the various (interfering) contributions (for example with an index p) are summed up.

However, modifications can also be made to the corresponding concept.

7.3.3 Extension to different carrier frequencies

Another idea of this invention is the extension of the mathematical model in equation (2.1), as well as the BCJR algorithm, to the separation of signals with two mutually different carrier frequencies f _{C 1} and f _{C 2} . These deviations are caused by movements of the transmitter or receiver or by inaccuracies in the oscillator used in the transmitter.

Note: As a rule, the deviations in the carrier frequencies are many times less than the symbol rate. However, if the deviation in relation to the symbol rate is high, in some cases the same matched filter can no longer be used for both processing paths and the system model should or must be adapted accordingly.

Both preprocessing branches (from the first two extensions) are each synchronized to the carrier frequencies of the ISi-affected components, i.e. the ECB transformation takes place with the carrier frequency of the ISI component and the two equations (2.1) and (3.1) are adjusted as follows:

The ISI component remains unchanged, only the ISI-free interference and the noise rotates, the statistical properties of the latter not being changed due to its rotationally invariant properties. Therefore, only the quantities a _{l 7n} and a _{2 in} equations (2.3) and (3.2) of the BCJR approach and in equations (2.5) and (3.4) of the complexity-reduced approach are time-variant and only these have to go through

and be replaced, which comparatively increases the computational effort only marginally.

In other words, by slightly modifying the calculation rules or formulas used, the concepts described above can be extended to the presence of different carrier frequencies. However, the corresponding extensions are to be regarded as optional.

8. _ Conclusions

Aspects of the present invention are briefly summarized again below.

A first aspect of the invention relates to an expansion of the iterative separation method using BCJR algorithm to double preprocessing with separate synchronization for both signals, with clock-synchronized to the disturbance and phase (and frequency) synchronized to the useful signal and the a posteriori symbol probabilities of the signals are to be used as a priori probabilities of the disturbance when using the BCJR for the other signal.

A second aspect of the invention relates to an expansion to an iterative separation method without BCJR algorithm with double preprocessing with separate synchronization for both signals, with clock-synchronized to the disturbance and phase (and frequency) synchronized to the useful signal and the a-posteriori symbol probabilities of the signals are to be used as a-priori probabilities of the disturbance in each case when applying the estimate for the other signal.

Another aspect of the invention relates to an expansion of the iterative separation method using the BCJR algorithm and the iterative separation method without the BCJR algorithm to include the reception of two signals with different carrier frequencies, both methods being adapted so that the phase of the clock-synchronized signal component is different keeps turning in every magazine. In this regard, it should be pointed out that the corresponding aspects of the invention can be used both individually and in combination with the exemplary embodiments described above.

In other words, for example, an embodiment according to FIGS. 1, 2a and 2b can optionally be supplemented by all aspects, features, functionalities and details that are included here with a view to expanding the iterative separation method using the BCJR algorithm to double preprocessing a separate synchronization for both signals are described.

Furthermore, for example, the exemplary embodiment according to FIGS. 3, 4a and 4b can optionally be supplemented by all aspects, features, functionalities and details that are described herein with regard to the extension to an iterative separation method without BCJR algorithm with double preprocessing with separate synchronization are described for both signals.

Moreover, for example, all exemplary embodiments can optionally be supplemented by the features, functionalities and details that are described here with regard to the expansion of both iterative separation methods to the reception of two signals with mutually different carrier frequencies.

In addition, it should be pointed out that the corresponding features, functionalities and details can be included in the corresponding exemplary embodiments both individually and in combination.

9. I mp learn entierunqs alternatives

Although some aspects have been described in connection with a device, it goes without saying that these aspects also represent a description of the corresponding method, so that a block or a component of a device can also be used as a corresponding method step or as a feature of a Process step is to be understood. Analogously to this, aspects that have been described in connection with or as a method step also represent a description of a corresponding block or details or features of a corresponding device. Some or all of the method steps can be performed by a hardware device (or using a Hardware apparatus), such as a microprocessor, a program- mable computer or an electronic circuit. In some embodiments, some or more of the most important process steps can be performed by such apparatus.

A signal encoded according to the invention, such as an audio signal or a video signal or a transport stream signal, can be stored on a digital storage medium or can be transmitted on a transmission medium such as a wireless transmission medium or a wired transmission medium, e.g. the Internet.

The encoded audio signal according to the invention can be stored on a digital storage medium or can be transmitted on a transmission medium such as a wireless transmission medium or a wired transmission medium such as the Internet.

Depending on the specific implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be carried out using a digital storage medium such as a floppy disk, a DVD, a Blu-ray disc, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, a hard disk or other magnetic memory or optical memory, on which electronically readable control signals are stored, which can interact or cooperate with a programmable computer system in such a way that the respective method is carried out. Therefore, the digital storage medium can be computer readable.

Some exemplary embodiments according to the invention thus include a data carrier which has electronically readable control signals which are able to interact with a programmable computer system in such a way that one of the methods described herein is carried out.

In general, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being effective to carry out one of the methods when the computer program product runs on a computer. The program code can for example also be stored on a machine-readable carrier.

Other exemplary embodiments include the computer program for performing one of the methods described herein, the computer program being stored on a machine-readable carrier.

In other words, an exemplary embodiment of the method according to the invention is thus a computer program which has a program code for carrying out one of the methods described here when the computer program runs on a computer.

A further exemplary embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for performing one of the methods described herein is recorded. The data carrier, the digital storage medium or the computer-readable medium are typically tangible and / or non-transitory or non-transitory.

A further exemplary embodiment of the method according to the invention is thus a data stream or a sequence of signals which represents or represents the computer program for performing one of the methods described herein. The data stream or the sequence of signals can, for example, be configured to be transferred via a data communication connection, for example via the Internet.

Another exemplary embodiment comprises a processing device, for example a computer or a programmable logic component, which is configured or adapted to carry out one of the methods described herein.

Another exemplary embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

A further exemplary embodiment according to the invention comprises a device or a system which is designed to transmit a computer program for performing at least one of the methods described herein to a receiver. The Transmission can take place electronically or optically, for example. For example, the receiver can be a computer, mobile device, storage device, or similar device. The device or the system can for example comprise a file server for transmitting the computer program to the recipient.

In some exemplary embodiments, a programmable logic component (for example a field-programmable gate array, an FPGA) can be used to carry out some or all of the functionalities of the methods described herein. In some exemplary embodiments, a field-programmable gate array can interact with a microprocessor in order to carry out one of the methods described herein. In general, in some exemplary embodiments, the methods are carried out by any hardware device. This can be universal hardware such as a computer processor (CPU) or hardware specific to the method, such as an AS1C.

The devices described herein can be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

The devices described herein, or any components of the devices described herein, can be implemented at least partially in hardware and / or in software (computer program).

The methods described herein can be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

The methods described herein, or any components of the methods described herein, can be carried out at least in part by hardware and / or by software.

The above-described embodiments are merely illustrative of the principles of the present invention. It is to be understood that modifications and variations of the arrangements and details described herein will be apparent to other skilled persons. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific The details presented herein with reference to the description and explanation of the exemplary embodiments are limited.

bibliography

[1] Johannes Huber. Patent application 102018202647.5 in Germany: Receiver and method for receiving a combination signal using probability density functions, Feb 2018.

[2] Johannes Huber. Patent application 102018202649.1 in Germany: Receiver and method for receiving a combination signal using separate in-phase and quadrature components, Feb 2018.

[3] Johannes Huber. Patent application for a low-cost receiver for two superimposed data signals (two-user receiver), Nov 2016

Claims

1. Receiver (100; 700: 750) for receiving a combination signal

(110; 710; 760), which has two separate signal components whose pulses are shifted from one another and / or whose carrier oscillations have a phase difference, wherein the receiver is designed to use a first series of samples (142, yi [k]) a first sample, the first sample being matched to a symbol phase of the first signal component;

wherein the receiver is configured to obtain a second series of samples (144, y ₂ [k]) using a second sample, the second sample being adapted to a symbol phase of the second signal component;

wherein the receiver is designed to calculate probabilities (114, Pi _{, m} [k]) of transmission symbols of the first signal component and probabilities (112, p _{2 m} [k]) of transmission symbols of the second signal component for a plurality of sampling times (k) based on obtain the first series of samples and the second series of samples;

wherein the receiver is designed, based on sample values (142, yi [k]) of the first sample and estimated or calculated probabilities (114, Pi, m [k]) for symbols of the first signal component, taking into account an intersymbol interference (i _{1 P} ) to determine probabilities (1 12, p _{2, m} [k]) for symbols of the second signal component between transmission symbols of the second signal component in the samples (142, yi [k]) of the first sampling; and wherein the receiver is designed, based on sample values (144, y ₂ [k]) of the second sample and estimated or calculated probabilities (112, p ₂ , [k]) for symbols of the second signal component, taking into account an inter- To determine symbol interference (i _{2 P} ) between transmission symbols of the first signal component in the samples (144, y ₂ [k]) of the second sampling probabilities (114, p _{1 m} [k]) for symbols of the first signal component.

2. Receiver (100; 70Q; 750) according to claim 1, wherein sampling times of the first sampling are set so that sampling of an output signal (132) of a matched filter (130) takes place in such a way that an output signal component of the matched filter that is based on the the first signal component is based, is essentially sampled interfering-free; and

wherein sampling times of the second sampling are set such that an output signal (132) of a signal-adapted filter (130) is sampled in such a way that an output signal component of the signal-adapted filter, which is based on the second signal component, is sampled essentially free of intersymbol interference.

3. Receiver (100; 700; 75Q) according to claim 1 or 2, wherein the receiver is designed to adapt the first sampling to the symbol phase of the first signal component and to the carrier phase of the second signal component; and

wherein the receiver is designed to adapt the second sampling to the symbol phase of the second signal component and to the carrier phase of the first signal component.

4. Receiver (100; 700; 750) according to one of claims 1 to 3, where the receiver is designed to receive first branch

Transition probabilities (222, Y _lk [i, j]) between states of a first state model which describes an intersymbol interference between transmission symbols of the second signal component in the samples of the first sample, based on the samples (142, 212, y ^ kj) of FIG first sample and estimated or calculated probabilities (292, pi _{, m} [k]) for symbols of the first signal component, and based on the first branch transition probabilities (222, Y _lk [i, j]) probabilities (252, p _{2 m} [k]) for symbols of the second signal component to be determined; and or

wherein the receiver is designed to second branch

Transition probabilities (272, Y2 _{, k} [j]) between states of a second state model, which describes an intersymbol interference between transmission symbols of the first signal component in the samples of the second sample, based on the samples (y ₂ [k]) of the second sample and estimated or calculated probabilities (252, p _{2, m} [k]) for symbols of the second signal component, and based on the second branch transition probabilities (272, Y ₂ , _k [i, j]) probabilities (292, pi _{, m} [k]) for symbols of the first signal component.

5. Receiver (100; 700; 750) according to claim 4, wherein the receiver is designed to calculate the probabilities (252, p _2, m [k]) for symbols of the second signal component using a first probability density function of a detection of transmission symbols to receive interference impairing the second signal component,

where the first probability density function

- a probability (292, Pi _{, m} [k]) of at least one transmission symbol of the first signal component

an expected contribution (v- _t ai _{, mb} ^{Kf1 ~ f2)} ) of at least one transmission symbol of the first signal component to a sample of the first sample, and - an expected contribution (219, i _{1 P} ) of an intersymbol interference between transmission symbols of the second signal component is taken into account.

6. Receiver (100; 700; 750) according to claim 5, wherein the receiver is designed, in an evaluation of the first probability density function, a time-variable contribution of a transmission symbol of the first signal component, which is due to a difference in carrier frequencies of the first signal component and the second Signal component results to be taken into account.

7. Receiver (1Q0; 700; 750) according to claim 4 or 5 or 6, wherein the receiver is designed to calculate the probabilities (292, Pi, m [k]) for symbols of the first signal component using a second probability density function of a detection to receive interference impairing transmission symbols of the first signal component,

where the second probability density function

a probability (252, p _{2, m} [k]) of at least one transmission symbol of the second signal component

an expected contribution (v ₂ a _2i m 6 ^{Kf2 f1)} ) of at least one ^{transmission symbol of} the second signal component to a sample of the second sample, and

- an expected contribution (i _{2, p} ) of an intersymbol interference between transmission symbols of the first signal component is taken into account.

8. Receiver (100; 700; 750) according to claim 7, wherein the receiver is designed, in an evaluation of the second probability density function, a time-variable contribution of a transmission symbol of the second signal component, which is due to a difference in carrier frequencies of the first signal component and the second Signal component results to be taken into account.

9. Receiver (100; 700; 750) according to one of claims 4 to 8, wherein the receiver is designed, based on the first branch transition probabilities (222, Y _lk [i, j]), first state transition probabilities (242, Pi _{, k} (ij) and to determine probabilities (252, p _{2, m} [k]) for symbols of the second signal component using the first state transition probabilities (242, Pi _{, k} (ij)); and / or

wherein the receiver is designed to obtain second state transition probabilities (291, p _{2 k} (i, j) based on the second branch transition probabilities {272, g _{2 k} [i, j]) and to obtain probabilities (292, Pi, m [k]) for symbols of the first signal component using the second state transition probabilities (291, p _{2, k} (U)).

10. Receiver (100; 700; 750) according to one of claims 1 to 9, wherein the receiver is designed to receive first branch

To determine transition probabilities (222, Yi _{, i} [i, j]) based on a sum of probability contributions for various possible transmission symbols of the first signal component, the probability contributions corresponding to the estimated or calculated probabilities (292, Pi _{, m} [k]) of the respective transmission symbols of the first signal component are weighted and a probability that a specified transmission symbol of the second signal component follows a specified sequence of transmission symbols of the second signal component, taking into account a current sample (142; 212, y ^ k]) of the first sample, an intersymbol - Describe interference (219, i _{1 P} ) between transmission symbols of the second signal component and a noise intensity (v ₃ ); and or wherein the receiver is designed to second branch

To determine transition probabilities (272, Y _{2 k} [i, j]) based on a sum of probability contributions for different possible transmission symbols of the second signal component, the probability contributions corresponding to the estimated or calculated probabilities (252, p _2, m [k]) of the respective transmission symbols of the second signal component are weighted and a probability that a specified transmission symbol of the first signal component follows a specified sequence of transmission symbols of the first signal component, taking into account a current sample (144, y ₂ [k]) of the second sample, an intersymbol -Interference (i _{2, p} ) between transmission symbols of the first signal component and a noise intensity (v ₃ ) describe.

1 1. Receiver (100; 700; 750) according to claim 10, wherein the receiver is designed to estimate transmission symbols of the second transmission signal component based on a choice of state transitions, the receiver being designed to select the state transitions so that a Overall transition probability, which is based on the branch

Transition probabilities (yi, _f c [t ,;]) based, is maximized; and / or wherein the receiver is designed to estimate transmission symbols of the first transmission signal component based on a selection of state transitions, wherein the receiver is designed to select the state transitions in such a way that an overall transition probability based on the branch transition probabilities (y ₂ , _f c [üi]) is maximized.

12. Receiver (100; 7Q0; 750) according to one of claims 1 to 11, wherein the receiver is designed to calculate first branch transition probabilities Y _lk [i, j] according to to obtain, where m is a running variable, ^'wherein Mi is a number of constellation points of the first signal component; where Pi. [k] are estimated or calculated probabilities of the respective transmission symbols of the first signal component in a time step k; where y _t [k] is a sample of the first sample at a time step k; where Vi is a gain factor of the first signal component; where a _{1 m is} a transmission symbol of the first signal component with transmission symbol index m, or where a _{1 m describes} a contribution of a transmission symbol of the first signal component with a transmission symbol index m to the sample yi [k], which in the case of a difference between a carrier frequency of the first signal component and a carrier frequency of the second signal component is a time-varying contribution a _1-m [k]; where f _G f _{2 describes} a phase shift between transmission symbols of the first signal component and transmission symbols of the second signal component; where ii _{, p describes} an intersymbol interference between transmission symbols of the second signal component; and where v _{3 describes} a noise intensity; and or wherein the receiver is designed to calculate second branch transition probabilities Y ₂ , k [i] according to

to obtain, where m is a running variable, where M _{2 is} a number of constellation points of the second signal component; where p _2, m [k] are estimated or calculated probabilities of the respective transmission symbols of the second signal component in a magazine k; where y ₂ [k] is a sample of the second sample from magazine k; where v _{2 is} a gain factor of the second signal component; where a _{2, m is} a transmission symbol of the second signal component with transmission symbol index m, or where a ₂ m describes a contribution of a transmission symbol of the first signal component with a transmission symbol index m to the sample y ₂ [k], which in the case of a difference between a carrier frequency of the first signal component and a carrier frequency of the second signal component is a time-variable contribution a _{2, m} [k]; where f ₂ - <ri describes a phase shift between transmission symbols of the second signal component and transmission symbols of the first signal component; where i _{2, p describes} an intersymbol interference between transmission symbols of the first signal component; and where v _{3 describes} a noise intensity.

13. Receiver (100; 700; 750) according to claim 12, wherein the receiver is designed to calculate, based on the first branch transition probabilities y _{1 fc} [ij], using a forward recursion _, probabilities Qi _{, k} [i] for a state i in a kth time step, and based on the first branch transition probabilities y _{1 fc} [i] using a backward recursion to determine probabilities βi _{, k + i} [j] for a state j in a k + 1th journal , and based on the probabilities ai _{, k} [i] for a state i in a k th journal and ßi _{, k + i} Ö] for a state j in a k + 1 th journal and using the first branch Transition probabilities y _{1 k} [i] first state transition probabilities (p _{1 k} (ij)) to be determined and, based on the first state transition probabilities (pi _{, k} (ij)), probabilities (p _{2, m} [k]) of transmission symbols of the second signal component to obtain;

and / or wherein the receiver is designed to determine probabilities a _{2, k} [i] for a state i in a k-th time step based on the second branch transition probabilities y _{2, k} ] using a forward recursion, and based on on the second branch transition probabilities Y _{2, k} l using a backward recursion to determine probabilities β _{2, k + i} ül for a state j in a k + 1-th journal, and based on the probabilities a _{2, k} [i ] for a state i in a k- th journal and ß _{2, k + i} ü] for a state j in a k + 1-th journal and un- using the second branch transition probabilities y _{2 fc} [i ,; ^' ] to determine second state transition probabilities (p _{2, k} (i, j)), and to obtain probabilities (Pi _, m [k]) of transmission symbols of the first signal component based on the second state transition probabilities.

14. Receiver (100; 700; 750) according to claim 13, wherein the receiver is designed to calculate the first state transition probabilities pi _{, k} (ij) according to

Pl, fc <Aj) = C _tran s, k «l, ki Vl.k U.nßl l]

to get, being is a normalization factor; and / or wherein the receiver is designed to calculate the second state transition probabilities p _{2 k} (i, j) according to

Pz, k (f _» i) ⁼ ^ trans, k ^ 2, k ii ^~ lY2, kj] ß2, k + l lj],

in which is a normalization factor.

15. Receiver (100; 700; 750) according to one of claims 1 to 14, wherein the receiver is designed to measure probabilities (p _{2, m} [k]) of transmission symbols of the second signal component for a plurality of sampling times (k) based on the first series of samples (yi [k]) and taking into account intersymbol interference (i _{1 p} ) between transmission symbols of the second signal component in the first series of samples by using a first instance of a BCJR method, and overlays (v ₁ ai _{, m} e ^{Ktf, 1 tp2)} ) to be taken into account as interference by sending symbols of the first signal component; and wherein the receiver is designed to obtain probabilities (pi _{, m} [k]) of transmission symbols of the first signal component for a plurality of sampling times (k) based on the second series of sampling values (y ₂ [k]) and thereby intersymbol interference ( i _{2 P)} to be considered between the transmission symbols of the first signal component in the second series of samples by ^'using a second instance of a BCJR method, and superimpositions (n to be considered as disturbances _{232 GT1b} ^{Kf2 · f1))} by transmission symbols of the second signal component.

16. Receiver (100; 700; 750) according to one of claims 1 to 15, wherein the receiver is designed to transmit symbols that are the basis of the first signal component, or probabilities (pi _{, m} [k]) of symbols that the first The signal component is to be determined by means of a trellis decoding method or based on the Bahl, Cocke, Jelinek and Raviv algorithm (BCJR algorithm); and

wherein the receiver is designed to transmit symbols on which the second signal component is based, or probabilities (p _2, mM) of transmission symbols on which the second signal component is based, using a T rellis decoding method or based on the algorithm according to Bahl, Cocke, Jelinek and Raviv (BCJR algorithm).

17. The method (500) for receiving a combination signal that has two separate signal components, the pulses of which are shifted from one another and / or the carrier oscillations of which have a phase difference, the method comprising obtaining (510) a first series of samples (142, yi [k]) using a first sample, the first sample being matched to a symbol phase of the first signal component;

the method comprising obtaining (520) a second series of samples (144, y ₂ [k]) using a second sample, the second sample being matched to a symbol phase of the second signal component;

wherein the method includes obtaining (530) probabilities (p _{1 m} [k]) of transmission symbols of the first signal component and of probabilities (p _{2, m} [k]) of transmission symbols of the second signal component for a plurality of sampling times (k) based on the first series of samples and the second series of samples comprises;

where based on sample values (yi [k]) of the first sample and estimated or calculated probabilities (pi _{, m} [k]) for symbols of the first signal component, taking into account an intersymbol interference (ii _{, p} ) between transmission symbols of the second signal component in the sample values (yi [k]) of the first sampling probabilities (p _{2, m} [k]) for symbols of the second signal component are determined; and based on sample values (y ₂ [k]) of the second sample and estimated or calculated probabilities (p _{2, m} [k]) for symbols of the second signal component, taking into account an intersymbol interference (i _{2, p} ) between transmission symbols of the first signal component in the sample values (y ₂ [k]) of the second sample, probabilities (pi _m [k]) for symbols of the first signal component are determined.

18. A computer program with a program code for performing the method according to claim 17 when the program runs on a computer.