DE102015103248B4 - RADIO COMMUNICATION SYSTEM USING NETWORK CODING - Google Patents

Abstract

A method of processing a message to be transmitted in a radio communications network, the method comprising:channel encoding a first bit stream representing a message;combining at least a portion of the channel encoded first bit stream with at least a portion of a second bit stream by applying an EXCLUSIVE OR -operating on the two bitstreams to generate a combined bitstream, the second bitstream at least partially representing the message; wherein the channel-coded first bit stream is designed to be sent over a first radio link of the radio communications network, and the combined bit stream is designed to be sent over a second radio link of the radio communications network.

Description

TECHNICAL FIELD

Embodiments described herein relate generally to the field of radio communications and, more particularly, to techniques for encoding and/or decoding signals transmitted over at least two radio links.

BACKGROUND

Radio communication networks use channel coding to improve the integrity and quality of the information received. Various channel coding techniques are known, among them forward error correction (FEC), for example using convolutional codes and/or block codes. In general, channel coding adds additional bits (called parity bits) to a bitstream to be transmitted and uses these additional bits to restore the transmitted information at the receiver even in the event that some of the transmitted bits are lost or incorrectly detected at the receiver.

Bit-level transmission between different devices is based on the functionality of the physical layer (PHY). The PHY functionality includes, among other things, channel coding and interleaving. Various channel coding schemes may be available and are defined in existing mobile communications standards. Typically, existing channel coding schemes of a standard should be retained in evolved PHY channel coding definitions to keep transmission compatible with standard or legacy devices, i.e. devices that do not support modified coding schemes to be implemented in the evolved standard. This imposes restrictions on extending channel encoding in a standard.

For these and other reasons, it is a goal to modify available physical layer coding schemes in existing standards to improve the performance of the mobile communications network while keeping transmission compatible with standard devices.

The font US 2003/0128769A1 describes a method for sending/receiving data depending on a channel condition in a CDMA communication system. Channel-coded data streams consisting of systematic bits and parity bits are divided into several data streams for a plurality of antennas in a distribution circuit. These multiple data streams are combined in multiplexing and modulation circuitry into antenna-specific data streams, each consisting of systematic bits or parity bits or a stream of mixed systematic bits and parity bits.

SUMMARY

Methods, transmitters, channel encoder equipment and channel decoder equipment according to the invention are set out in the independent claims. Additional features for advantageous embodiments are specified in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 ist eine schematische Darstellung eines beispielhaften Funkkommunikationsnetzes.
• 2 ist ein gerichteter Graph, der ein klassisches Butterfly-Netz veranschaulicht.
• 3 ist ein Modell, das eine beispielhafte Anwendung des klassischen Butterfly-Netzes von 2 auf ein Funkkommunikationsnetz veranschaulicht.
• 4 ist ein Blockbild, das ein allgemeines Modell eines Funkkommunikationsnetzes veranschaulicht, wie es durch die Anwendung des Modells von 3 auf ein beispielhaftes heterogenes Funkkommunikationsnetz erhalten wird.
• 5 ist ein Blockbild, das ein eingeschränktes Modell eines beispielhaften Funkkommunikationsnetzes veranschaulicht.
• 6 ist eine Darstellung eines Funkkommunikationsnetzes, welche Funkverbindungen, die für Legacy-Empfänger verfügbar sind, und Funkverbindungen, die für Legacy-Empfänger nicht verfügbar sind, anzeigt.
• 7 veranschaulicht eine Mehrzahl direktionaler Funkverbindungen und eine gemeinsam genutzte Funkverbindung zur Datenübertragung in einem Funkkommunikationsnetz.
• 8A ist ein Blockbild, das Kanalcodierer und einen Kanaldecodierer veranschaulicht, wie sie zum Senden und Empfangen von Daten über zwei Funkverbindungen in einem Funkkommunikationsnetz verwendet werden.
• 8B ist ein Blockbild, das Kanalcodierer und Kanaldecodierer veranschaulicht, wie sie zum Senden und Empfangen von Daten über drei Funkverbindungen in einem Funkkommunikationsnetz verwendet werden.
• 9 veranschaulicht einen beispielhaften Fehlerkorrekturansatz für einen Bitstrom, der über eine erste Funkverbindung empfangen wird, durch einen netzcodierten Bitstrom, der über eine zweite Funkverbindung empfangen wird.
• 10 ist eine beispielhafte Darstellung eines Faltungskanalcodierers.
• 11 veranschaulicht einen beispielhaften Datenübertragungsansatz unter Verwendung von drei Funkverbindungen, um mehr Flexibilität und/oder weniger Fehler zu erhalten.
• 12 ist ein Blockbild, das eine Mehrzahl möglicher Empfängerarchitekturen veranschaulicht, wie sie in einem Funkkommunikationsnetz verwendet werden können.
• 13 ist eine Darstellung eines Funkkommunikationsnetzes, das den Ansatz einer Netzcodierung für eine Mobilstation-zu-Mobilstation-Verbindung anzeigt.
• 14 ist ein Blockbild, das eine beispielhafte Implementierung von zwei herkömmlichen Faltungskanalcodierern und eine beispielhafte Implementierung eines Kombinierers zur Netzcodierung veranschaulicht.
• 15 ist eine grafische Darstellung, welche die Bitfehlerrate (Bit Error Rate, BER) gegenüber Eb/No von zwei Funkverbindungen mit und ohne Netzcodierung veranschaulicht.

The accompanying drawings are included to provide a better understanding of examples of the disclosure and are incorporated into and form a part of this specification. The drawings illustrate examples and, together with the description, serve to explain principles of examples. Other examples and many of the intended advantages of examples will become clearer by reference to the following detailed description.

• 1 is a schematic representation of an exemplary radio communication network.
• 2 is a directed graph illustrating a classic butterfly network.
• 3 is a model that is an exemplary application of the classic butterfly network from 2 illustrated on a radio communication network.
• 4 is a block diagram illustrating a general model of a radio communications network as determined by applying the model of 3 is obtained on an exemplary heterogeneous radio communication network.
• 5 is a block diagram illustrating a limited model of an exemplary radio communications network.
• 6 is a representation of a radio communications network showing radio links available to legacy receivers and radio links not available to legacy receivers.
• 7 illustrates a plurality of directional radio links and a shared radio link for data transmission in a radio communications network.
• 8A is a block diagram illustrating channel encoders and a channel decoder as used to send and receive data over two radio links in a radio communications network.
• 8B is a block diagram illustrating channel encoders and channel decoders as used to send and receive data over three radio links in a radio communications network.
• 9 illustrates an example error correction approach for a bitstream received over a first radio link by a network encoded bitstream received over a second radio link.
• 10 is an exemplary representation of a convolutional channel encoder.
• 11 illustrates an example data transmission approach using three radio links to provide more flexibility and/or fewer errors.
• 12 is a block diagram illustrating a variety of possible receiver architectures that can be used in a radio communications network.
• 13 is a representation of a radio communications network indicating the network coding approach for a mobile station-to-mobile connection.
• 14 is a block diagram illustrating an example implementation of two conventional convolutional channel encoders and an example implementation of a combiner for network coding.
• 15 is a graphical representation that illustrates the Bit Error Rate (BER) versus Eb/No of two radio links with and without network coding.

DESCRIPTION OF EMBODIMENTS

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and which show, by way of illustrative embodiments, how the invention may be practiced. It will be appreciated that other embodiments may be used and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

It is to be understood that the features of the various exemplary embodiments described herein may be combined with one another unless specifically stated otherwise. Furthermore, like reference numerals designate corresponding identical or similar parts.

As used in this specification, the terms “coupled” and/or “connected” are not intended to generally mean that the elements must be directly coupled or connected to one another; intermediate functional elements may be provided between the “coupled” or “connected” elements. However, while not limited to this meaning, the terms "coupled" and/or "connected" may also be understood to, where appropriate, disclose an implementation in which the elements are directly coupled or connected to one another, without any intervening elements in between the “coupled” or “connected” elements.

It will be appreciated that embodiments may be implemented in discrete circuits, partially integrated circuits, or fully integrated circuits. Further, embodiments may be implemented on a single semiconductor chip or on multiple interconnected semiconductor chips. Furthermore, it is understood that embodiments may be implemented in software or in dedicated hardware, or partly in software and partly in dedicated hardware.

Methods and devices described herein may be implemented in a base station (NodeB, eNodeB) or a mobile device (or mobile station or user equipment (UE)). The devices described may include integrated circuits and/or passive elements and may be manufactured according to various technologies. For example, the circuits can be designed as logic integrated circuits, analog integrated circuits, mixed-signal integrated circuits, optical circuits, memory circuits, integrated passive elements, etc.

The transmitters, channel encoders and channel decoders and receivers described here can be used for various wireless communication networks. The terms “network”, “system” and “radio communication system” can be used interchangeably here.

A radio communications network as described herein may be a heterogeneous radio communications network. A heterogeneous radio communications network can be a network in which different radio access technologies (RATs) are integrated and can be managed together. For example, 5G ( ^5th Generation) communication systems support various RATs.

Different RATs use different radio access technologies specified in relevant mobile communications standards. As an example, consider a RAT that implements Code Division Multiple Access (CDMA) technology. As an example, a WCDMA (Wideband CDMA) system defined by 3GPP ( ^3rd Generation Partnership Project) is a system that uses CDMA technology. Other networks that implement CDMA are Universal Terrestrial Radio Access (UTRA), cdma20000, etc. UTRA includes wideband CDMA (W-CDMA) and other CDMA variants. cdma2000 includes IS-2000, IS-95 and IS-856 standards. Other RATs considered here may implement TDMA (Time Division Multiple Access) and/or FDMA (Frequency Division Multiple Access) technologies, such as Global System for Mobile Communications (GSM) networks and derivatives thereof, such as Enhanced Data Rate for GSM Evolution (EDGE), Enhanced General Packet Radio Service (EGPRS), including, for example, developments such as HSPA (High-Speed Packet Access) and/or HSDPA (High-Speed Downlink Packet Access). In addition, RATs considered here may use Orthogonal Frequency Division Multiplexing (OFDM) technology, for example Long Term Evolution (LTE) networks or networks based on Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20 or Flash-OFDM.RTM. In addition, RATs that implement millimeter wave (mmWave) technologies can be considered here. As an example, 5G communication systems will support a mmWave RAT.

Although examples are disclosed herein with respect to LTS and LTE-A wireless networks, examples and the teachings herein may equally be applied to other wireless network standards such as, but not limited to: wide area cellular radio communications technology, e.g., comprising Global System for Mobile Communications- (GSM) radio communications technology, General Packet Radio Service (GPRS) radio communications technology, Enhanced Data Rates for GSM Evolution (EDGE) radio communications technology, and/or Third Generation Partnership Project (3GPP) radio communications technology, e.g. UMTS (Universal Mobile Telecommunications System), FOMA (Freedom of Multimedia Access), 3GPP LTE (Long Term Evolution), 3GPP LTE Advanced (Long Term Evolution Advanced), CDMA2000 (Code Division Multiple Access 2000), CDPD (Cellular Digital Packet Data), Mobitex, 3G ( Third Generation), CSD (Circuit Switched Data), HSCSD (High-Speed Circuit-Switched Data), UMTS (3G) (Universal Mobile Telecommunications System (Third Generation)), W-CDMA (UMTS) (Wideband Code Division Multiple Access ( Universal Mobile Telecommunications System)), HSPA (High Speed Packet Access), HSDPA (High-Speed Downlink Packet Access), HSUPA (High-Speed Uplink Packet Accesss), HSPA+ (High Speed Packet Access Plus), UMTS-TDD (Universal Mobile Telecommunications System - Time-Division Duplex), TD-CDMA (Time Division - Code Division Multiple Access), TD-SCDMA (Time Division - Synchronous Code Division Multiple Access), 3GPP Rel. 8 (Pre-4G) ( ^3rd Generation Partnership Project Release 8 (Pre- ^4th Generation)), 3GPP Rel. 9 ( ^3rd Generation Partnership Project Release 9), 3GPP Rel. 10 ( ^3rd Generation Partnership Project Release 10), 3GPP Rel. 11 ( ^3rd Generation Partnership Project Release 11), 3GPP Rel. 12 ( ^3rd Generation Partnership Project Release 12), 3GPP Rel. 13 ( ^3rd Generation Partnership Project Release 13), 3GPP Rel. 14 ( ^3rd Generation Partnership Project Release 14), UTRA (UMTS Terrestrial Radio Access), E-UTRA (Evolved UMTS Terrestrial Radio Access), LTE Advanced (4G) (Long Term Evolution Advanced (4 ^th Generation)), cdmaOne (2G), CDMA2000 (3G) (Code Division Multiple Access 2000 (Third Generation)), EV-DO (Evolution-Data Optimized or Evolution-Data Only), AMPS (1G) (Advanced Mobile Phone System (1 ^st Generation)), TACS/ETACS (Total Access Communication System/Extended Total Access Communication System), D-AMPS (2G) (Digital AMPS (2 ^nd Generation)), PTT (Push-totalk), MTS (Mobile Telephone System), IMTS (Improved Mobile Telephone System), AMTS (Advanced Mobile Telephone System), OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), MTD ( Swedish abbreviation for Handyisystem D or Mobile Telephony System D), Autotel/PALM (Public Automated Land Mobile), ARP (Finnish for Autoradiopuhelin “car radio telephone”), NMT (Nordic Mobile Telephony), Hicap (high-capacity version of NTT (Nippon Telegraph and Telephone )), CDPD (Cellular Digital Packet Data), Mobitex, Data-TAC, iDEN (Integrated Digital Enhanced Network), PDC (Personal Digital Cellular), CSD (Circuit Switched Data), PHS (Personal Handy-phone System), WiDEN ( Wideband Integrated Digital Enhanced Network), iBurst, Unlicensed Mobile Access (UMA, also referred to as 3GPP Generic Access Network or GAN standard), Wireless Gigabit Alliance (WiGig) standard, mmWave standards in general (wireless systems operating at 10 to 70 GHz and above), WiFi (IEEE 802.11a/b/g/n/ac/ad/af/etc.), WiMAX (IEEE 802.16a/e), etc.

It should be noted that the mobile communications standards referred to here are intended to include all existing and future versions of the standard (e.g. IEEE 802.11/a/b/g/ac/ad/n/af/ etc... for Wi-Fi based of IEEE 802.11).

Although some RATs provide non-directional or quasi-omnidirectional transmission, other RATs, such as a mmWave RAT, may provide transmissions that are typically (highly) directive, e.g. through the use of highly directive patch antennas, etc. As an example, LTE and /or Wi-Fi provides quasi-omnidirectional transmission, while mmWave technology provides (highly) directional transmission.

The term (quasi-) omnidirectional (or (quasi-) isotropic) as used in this disclosure for a technology or a radio link can mean, for example, technologies that use a radio link frequency range of less than, for example, 6 GHz, whereas the Expression directional, which is used here for a technology or a radio connection, e.g. can mean mmWave technologies that use a radio connection frequency range of, for example, above 6 GHz. It should be noted that within this meaning, some technologies with “weaker” directional properties, such as LTE, can still be considered here as (quasi-)omnidirectional technologies rather than directional technologies.

More specifically, in the case where sector-based transmission is undertaken, as is typically the case for cellular base stations, the proposed new techniques can be applied to a single sector or to all sectors or to any combination of sectors. Other sectors would then fall back on the traditional coding schemes. Also, in the case where beamforming is performed (and thus the entire space is not covered by directional transmission), the proposed scheme can be applied to the channel codes in the beamforming based system or subsystem (in the case that some Transmissions are combined, some employing beamforming or any other form of directional transmission, and others employing (quasi-)isotropic or (quasi-)omnidirectional transmission). Typical single antenna transmissions (such as monopole or dipole antenna based transmissions) are considered to be (quasi) isotropic or (quasi) omnidirectional.

1 illustrates a schematic representation of an exemplary radio communication network 100, of which a mobile station and two base stations BS1, BS2 are shown. As an example, the radio communications network 100 may be a 5G network. The radio communication network 100 may include a shared radio link 110, for example with a carrier frequency of less than 6 GHz, which connects the mobile station MS with the two (or more) remote base stations BS1, BS2. The shared radio link 110 may be a quasi-isotropic radio link. Furthermore, the mobile station MS can be connected to the first base station BS1 via a first directional radio connection 120_1 and can be connected to the second base station BS2 via a second directional radio connection 120_2. It should be noted that the mobile station MS may be a handheld radio device, a mobile phone or any similar device. A mobile station MS can also be referred to here as “user equipment” (UE). The base stations BS1, BS2 can include any base stations be used in radio communication networks, e.g. base stations with macro cells, pico cells, femto cells, target cells, etc. As an example, base stations with different capabilities, e.g. different TX power classes, may be involved. Thus, the term eNodeB, as sometimes used for base stations described herein, is to be construed to include various specific terms such as MeNB (Macro-eNodeB), PeNB (PicoeNodeB) and HeNB (Femto/Home-eNodeB), etc. The Base stations BS1, BS2 can send and/or receive mmWave transmissions, for example with a carrier frequency equal to or greater than 6 GHz.

The following addresses the question of how to modify available physical layer (PHY) channel coding schemes of existing standards so that common transmission in at least two RATs can be achieved. Examples of the existing standards can be, for example, LTE, Wi-Fi, etc., or derivatives thereof. The existing standard or standards can, for example, use the shared radio connection 110. The future standard may be an implementation of any RAT using, for example, the (highly) directive radio links 120_1, 120_2.

Embodiments described below are directed to improving the performance of the radio communications network 100 while leaving the PHY layer channel coding schemes used over the shared radio link 110 substantially unchanged. Thus, the transmissions in the radio communication network 100 remain compatible with standard (or legacy) mobile stations MS that only support the channel coding schemes used for the shared radio link 110, e.g. those specified in LTE or Wi-Fi, etc., and derivatives thereof PHY channel coding schemes. Further, embodiments described herein may enable implementation of proprietary devices (i.e., extensions not defined in any underlying standard) that support the transmission method in a heterogeneous radio communications network 100 as described herein. These devices (transmitter, channel encoder, receiver, channel decoder) can remain compatible with legacy devices because existing channel coding schemes used for one of the shared radio link 110 and the first and/or second directional radio links 120_1/120_2 are not changed , although the modifications implemented in channel decoding are applied to the other of the shared radio link 110 and the first and/or second directional radio links 120_1/120_2.

Thus, embodiments described herein utilize a modification of existing PHY channel coding schemes in a context of a (heterogeneous) radio communications network 100 with a shared radio link 110 and (highly) directional radio links 120_1, 120_2 to be operated simultaneously. As already stated, the shared radio link 110 may be a quasi-omnidirectional (quasi-isotropic) radio link and/or may typically operate in a frequency range of less than 6 GHz, and the (highly) directional radio links 120_1, 120_2 may typically be mmWave. Be radio connections and/or operate in a frequency range of more than, for example, 6 GHz (it should be noted that, although the mmWave spectrum is sometimes defined in technology as starting at 30 GHz, here the term mmWave refers to a frequency range of e.g. about 3 or 6 GHz to e.g. about 300 GHz is used). This approach allows a first transmission bitstream to be left substantially unchanged (e.g., sent over the shared radio link 110, e.g., operating at less than 6 GHz) while at least a second transmission bitstream is modified to produce a so-called combined bitstream. This combined bit stream is then to be sent via another radio connection (e.g. via one of the first and second directional radio connections 120_1, 120_2). The combined bitstream can be generated by combining coded bits of the first transmission bitstream with bits of the second transmission bitstream.

On the receiver side, a standard (legacy) receiver will still be able to decode the first transmit bitstream (encoded using an existing RAT), and a proprietary receiver will be able to fully decode the first transmit bitstream and the combined bitstream, which are common are sent in the (heterogeneous) radio communication network 100. Note that it is also possible to send the first bit stream over one of the first and second directional radio links 120_1, 120_2, and to send the combined bit stream over the shared radio link 110.

Embodiments described herein may utilize features of a so-called butterfly network, which is known in network coding theory. 2 illustrates a classic Butterfly Net 200 design. The butterfly network 200 is a network coding example using the directed graph from 2 can be modeled. It includes a single message source S, which has information A and B to be sent to two specific recipients (destinations) X and Y. For example, the information A and B may be encoded as a single bit A = 0 or 1 and a single bit B = 0 or 1, respectively (this example can be generalized to bit packets A and B, where each bit packet may include n bits, n = 1, 2, ...). Each recipient X and Y wants both information A and B. Everyone who is in 2 The nine channels illustrated can only carry a single value, e.g. a single bit (or bit packet) is sent in each time slot. It is assumed that each channel, as indicated by the directed edges (lines) in 2 represents, is error-free, and the single source S wants to send bits A and B to the two receivers X and Y at the highest possible rate.

By simply replicating information (i.e. bits A or B) at each node T, U, V, W, the maximum multicast rate would be 1.5 bits per unit time. This is the maximum rate achievable by any “routing solution” if the intermediate node V can only perform one bit replication. In this case, the central channel between intermediate node V and node W would only be able to carry bit A (of information A) or bit B (of information B), but not both. In the case of transporting information A, receiver X would receive information A twice and would not receive information B at all. Choosing to send information B through the intermediate node V would lead to the same problem of receiving only one piece of information, namely information B, for the receiver Y. That is, routing is inadequate because no routing scheme can send both information A and B to both receivers X and Y at the same time.

How out 2 As can be seen, the "network coding solution" can achieve a throughput of two bit packets per time slot because the intermediate node V no longer blocks a bit packet A or B, but their modulo 2 sum A ⊕ B through the shared channel between the intermediate node V and the intermediate node W sends. The modulo 2 sum corresponds to and B within each time slot, all nine channels are used only once, whereas without network coding, ie in the case of using the routing solution, at least one channel would have been used twice. That is, in this design, network coding not only provides better throughput than can be achieved with routing alone, but also provides maximum multicast throughput, making it optimal.

In embodiments described below, network coding is used as in connection with 2 explained, applied to (heterogeneous) radio communication networks 100 with the potential to maximize throughput (ie, bit rate) and reduce latency and energy consumption. As described in more detail below, a proprietary receiver (i.e. implemented in a mobile station MS or base station BS1, BS2) would be able to fully decode both information A and B, while a legacy receiver (e.g. receiver X) would only be able to would be to decode the left direct communication channel (node T to receiver X), and/or a legacy receiver (receiver Y) would only be able to decode the right direct communication channel (node U to receiver Y). While (proprietary) receivers according to embodiments described herein can use the middle path channel (node V to node W), legacy receivers would not be able to use the combined information sent over this channel.

As an example, the single source S can be implemented in a mobile station MS, while the two receivers X and Y can be implemented as receivers in base stations BS1 and BS2, respectively. As explained in more detail below, for example, for reasons of improved error correction, flexibility, etc., it is also possible to use a common receiver (i.e. a single receiver) to process the information A, B and A ⊕ B received from the receivers X and Y are received.

3 illustrates an exemplary application of the classic Butterfly Net 200, which is in 2 is shown in the (heterogeneous) radio communication network 100, as in 1 illustrated. The features described above in connection with the classic butterfly network 200 may equally apply to the radio communications network 100 and repetition of these features will be omitted for brevity.

A single message source S, for example a mobile station MS, outputs information A and B (here again coded by bits A and B), which relate to the same message, for example, to a first message source S1 and a second message source S2. These news sources S1 and S2 can be “virtual” news sources implemented in the same device as a “real” single news source S are. The first message source S1 then sends the information A over the first directional radio link 120_1 and the second message source S2 sends the information B over the second directional radio link 120_2. Both message sources S1 and S2 send the information A and B to a combiner C. The combiner C is designed to generate a first bit stream which encodes information A (and thus contains the bit A or bit packet A) which is received from the message source S1. and combining a second bit stream encoding information B (and thus containing bit B or bit packet B) received from the message source S2. The combiner C outputs combined information that is sent over the shared radio link 110. On the other hand, the first bit stream output from the message source S1 is sent over the first directional radio link 120_1 and then the second bit stream output from the second message source S2 is sent over the second directional radio link 120_2.

A first receiver, e.g. a base station BS1, receives the transmitted first bit stream and the transmitted combined bit stream, performs an operation OP1 on these two bit streams and can receive the first bit stream carrying information A and the second bit stream carrying information B. decode. Similarly, a second receiver, for example a second base station BS2, receives the transmitted second bit stream and the transmitted combined bit stream, performs an operation OP2 thereon, and can decode the first bit stream carrying information A and the second bit stream carrying information B .

It should be noted that the in 2 and 3 The characters A and B used can each refer to information A and B or to bit packets A and B that encode this information A and B, respectively.

4 is a representation that is an application of the general model of 2 and 3 shows an exemplary heterogeneous radio communications network 100 using an existing RAT that provides quasi-omnidirectional transmission and a RAT that provides highly directional mmWave transmission. The news source S1 refers to S1 of 3 and the message source S2 refers to S2 of 3 . The first bit stream output from the message source S1 may be channel encoded in a channel encoder 401 using a first channel code 1, and the second bit stream output from the message source S2 may be channel encoded by an (optional) channel encoder 402 using a second channel codes 2 can be channel coded. The channel encoder 401 performs channel encoding corresponding to a RAT1 (e.g., a RAT that provides unidirectional transmission), and the channel encoder 402 performs channel encoding according to a RAT2 (e.g., a RAT that provides unidirectional transmission).

The channel encoded bit streams output from the first channel encoder 401 and the second channel encoder 402 may then be input to a combiner 430 corresponding to the combiner C of 3 can correspond. The combiner 430 may provide a first combined bitstream 431 and a second combined bitstream 432.

These two bit streams 431 and 432 can be further encoded (e.g. interleaved, punctured, etc.) according to the PHY of RAT1 and RAT2, respectively. The optional further channel coding carried out by the (optional) further channel encoder 411 is adapted and, for example, optimized for a RAT1 transmission, and the (optional) further channel coding carried out by the (optional) further channel encoder 412 is adapted for a RAT2 -Transmission adapted and optimized, for example.

Here, the combination or network coding operation is applied behind the respective, for example, two channel coding operations (for example, the channel encoder 401, 402). This approach can be easily extended to any number of RATs to be combined and thus to any number of channel codes to be combined. For example, this can be achieved through a hierarchy, i.e. in the first stage a combination or network coding operation is applied to first stage channel encoders (e.g. channel encoders 401, 422), another such network coding operation is applied to second stage channel encoders (e.g. channel encoders 411, 412 ). The order of the channel encoder outputs, which are to be combined, for example by a network coding operation, can also be chosen as required, any possibility can be provided. Ie, instead of combining the encoder outputs 401 and 402 and, for example, the encoder outputs 411 and 412, one could combine the encoder outputs 401 and 412 and/or 402 and 411 or any other permutation across all stages. It is also possible that the outputs of the network coding operation of a particular stage (e.g wise of the second stage) can be combined, for example by a network coding operation, with the outputs of a previous stage (for example the first stage) or the direct outputs of the original channel encoder. Then the outputs of the coding stage consist of any suitable combination of the outputs of the original channel encoders and/or the outputs of the network coding operations of any of the stages.

It is also possible that the proposed combination or network coding operation (or a similar operation) is not applied to the outputs of the relevant channel encoders, but elsewhere in the communication chain, e.g. to the inputs of the channel encoders, e.g. in the MIMO/SIMO coding stages /MISO (Multiple Input Multiple Output/Single Input Multiple Output/Multiple Input Single Output), etc. It can also be applied in the Medium Access Control Layer or any other ISO layer.

4 illustrates a propagation channel 110_1 and a propagation channel 110_2 of the shared radio link 110 corresponding to, for example, RAT1, and further the first directional radio link 120_1 corresponding to a first propagation channel of RAT2 and the second directional radio link 120_2 corresponding to a second propagation channel of RAT2. As an example, the propagation channel 110_1 can be a channel with a frequency <6 GHz of the (quasi-) omnidirectional radio link, the propagation channel 110_2 can be a channel with a frequency <6 GHz of the (quasi-) omnidirectional radio link, the first propagation channel can be a mmWave channel of the first directional radio link 120_1, and the second propagation channel may be a mmWave channel of the second directional radio link 120_2.

In the general model of a radio communication network 400, which is in 4 is shown, a first receiver R1 and a second receiver R2 are illustrated. The first receiver R1 receives the output of the first propagation channel 110_1 of RAT1 and the output of the first propagation channel 120_1 of RAT2. Assuming that the first receiver R1 is a legacy RAT1 receiver, the first receiver R1 can decode the output of the propagation channel 110_1 to obtain the message sent by the message source S1. In the case that the first receiver R1 is an enhanced RAT1 receiver that can decode information received over the RAT2 directional propagation channel 120_1, the first receiver R1 will be able to decode information from the message source S1 and information from the message source S2 . The same applies analogously to the second receiver R2, which receives the output of the second RAT1 propagation channel 110_2 and the output of the second directional RAT2 propagation channel 120_2.

5 illustrates a model of an exemplary radio communications network 500. The model may be a restricted model of the general model of the in 4 radio communication network 400 shown. The restrictions may refer to self-imposed limits to conform to a given standard, for example a RAT1 standard.

Similar to the radio communication network 400, the radio communication network 500 may include a message source S1 and a message source S2. The news source S1 and the news source S2 can also be referred to as news sources S1 and S2. Further, the radio communication network 500 (or more precisely, a transmitter implemented in the radio communication network 500) includes a first channel encoder 501 and an (optional) second channel encoder 502. The first channel encoder 501 may correspond to the first channel encoder 401, and the second channel encoder 502 may correspond to the second Channel encoder 402 from 4 are equivalent to.

The radio communication network 500 (or more precisely, a transmitter implemented in the radio communication network 500) further includes a combiner 530. The combiner 530 may correspond to the combiner 430 of the radio communication network 400. The combiner 530 has a first input that receives a coded first bitstream from the first channel encoder 501 and may have a second input that receives a coded second bitstream from the channel encoder 502. Note that the second channel encoder 502 may be optional. If the channel encoder 502 is missing, the combiner 530 receives at its second input the (non-channel encoded) second bit stream from the second message source.

The combiner 530 in this example performs low-complexity, zero-delay encoding on the input bitstreams. Low complexity encoding with zero delay can apply EXCLUSIVE-OR processing to the input bit streams from the combiner 530. As described in more detail below, various different operations using exclusive-or processing on the incoming bit streams may be available in combiner 530 for low complexity, zero delay encoding.

The combiner 530 may use rateless encoding of the incoming bit streams. Rateless encoding uses a code rate of 1.

The combiner 530 may use Raptor encoding of the incoming bitstreams. A Raptor encoding means a Raptor (Rapid Tornado) code is applied. Raptor codes encode a given message consisting of a k number of bits into a potentially unbounded sequence of encoded bits, such that knowledge of any k or more encoded bits allows the message to be recovered with a certain non-zero probability .

Apart from the code examples above, any other code - guessless or not - can be used instead. It is also possible to use a convolutional code, a turbo code, a low-density parity check code, a Reed-Solomon code, any block code, etc., for the combination operation. Likewise, it is typically possible to combine one or more of the "original" channel codes together with the new encoding operation with a new obtained code (replacing both the original code and the new encoding operation).

The encoded first bit stream output from the first encoder 501 is sent via a first propagation channel 510. The first propagation channel 510 may correspond to a first propagation channel 110_1 or 110_2 of RAT1, as in 4 illustrated. The transmitted first bit stream is directed to a first message sink 540_1 and to a second message sink 540_2. The first and second message sinks 540_1, 540_2 can be transmitted by the first and second receivers R1 and R2, respectively 4 be implemented. That is, if the first message sink 540_1 is implemented by a RAT1 legacy receiver, and if the second message sink 540_2 is implemented by another RAT1 legacy receiver, both receivers are able to recover the information (message) that from the first message source over the shared propagation channel 510.

The output of the combiner 530 is sent over a first directive radio link 520_1 and a second direct radio link 520_2. In one aspect, the combined bit stream sent over the first directive propagation channel 520_1 may be the same combined bit stream sent over the second directive propagation channel 520_2.

The first message sink 540_1 receives the transmitted bitstream output from the shared propagation channel 510 and the combined bitstream output from the first directive propagation channel 520_1. If the first message sink 540_1 is implemented by an advanced receiver operating with RAT1 and RAT2, the first message sink 540_1 is able to decode the message output from the first message source S1 as well as the message output from the second message source S2.

The second message sink 540_2 receives the bit stream sent over the shared propagation channel 510 and the combined bit stream sent over the second directive propagation channel 520_2. If the second message sink 540_2 is implemented by an advanced receiver operating with RAT1 and RAT2, the second message sink 540_2 may be able to decode the message output from the first message source S1 and the message output from the second message source S2.

It should be noted that the messages sent by the first and second message sources S1, S2 may be dependent on each other. As an example, the second bit stream output from the second message source S2 may be derived from either a bit stream output from a single message source S representing the message (see 2 , 3 ), or from the first bit stream output by the first message source S1. As an example, the bits included in the second bit stream output from the second message source S2 may be redundant bits of the bits included in the first bit stream output from the first message source S1. In this case, the “network coding” concept used in the radio communication networks 400, 500 is implemented, no decoding of two specific messages in each of the receivers R1, R2 ( 4 ) or each of the message sinks 540_1, 540_2 ( 5 ), but can be used to improve the performance of the network in terms of throughput, decoding quality and consequently latency if an ARQ (Automated Repeat Request) or Hybrid ARQ (HARQ) method - in particular a HARQ method with soft combination - is used for channel coding in the radio communication networks 400, 500, especially in RAT1. For example, the single news source S (in 4 , 5 , 6 , 8A , 8B , 14 not shown), from which the individual bit stream originates (from which the first and second bit streams are derived), may for example be a single source encoder, such as a video encoder, an audio (or speech) encoder, etc. For example, this single bit stream may already contain redundancy since it could be source coded, as is well known. The single bitstream (and/or the first and second bitstreams) may be user data from these message sources. Thus, the individual news source S1 can also be referred to as a single data source S1, and the first and second news sources S1, S2 can also be referred to as data sources S1 and S2, respectively. In all these cases, the combiner C combines at least some of the bits of the first user data bitstream and the second user data bitstream, e.g., every bit or every second bit or every third bit, etc., of the first user data bitstream and/or the second user data -Bitstreams. “At least some of the bits” of a bit stream is also referred to herein as “at least a portion” or “at least a subset” of a bit stream.

It should be noted that the underlying concept of “network coding” as explained above is considered an alternative solution to the “brute force” approach of substantially modifying the physical layer (PHY) by defining an overall optimal channel code for a heterogeneous radio communication network can. This approach (of defining an overall optimal channel code for a radio communications network supporting a plurality of RATs) would potentially result in (slightly) better system performance compared to the solution presented here. However, a significant change in PHY coding would only be possible with a new generation of devices and would require integration of the new PHY coding into the related standards or system designs. Typically, such an integration would involve a lot of time, effort and standardization work. Furthermore, a significant change in the PHY coding scheme is difficult to incorporate into a standard, and any overall optimal code would, in any case, significantly increase the overall complexity in a transmitter and/or receiver.

Therefore, it is overall questionable whether any "brute force" approach to substantially modifying the channel coding scheme into an optimal coding algorithm would be worth the additional complexity and effort of standardization and of elaborating and defining such an optimal coding scheme.

In complete contrast to the brute force approach, the concept disclosed here leaves a first transmission bitstream unchanged (e.g. the bitstream sent over the shared and/or the (quasi-)omnidirectional radio link). A second transmission bitstream is modified by combining a channel-encoded bitstream from the first (original) channel encoder 501 and a second bitstream, optionally channel-encoded by a second (original) channel encoder 502. This modification can be achieved by not noticeably increasing complexity in the transmitter, since the combiner 430, 530 can only add, for example, an EXCLUSIVE OR operation to the transmitter functionality (the combiner 430, 530 and in particular an EXCLUSIVE OR operation in the combiner 430, 530 used can be implemented in hardware or in software).

As for the receivers R1, R2 (which include, for example, the message sinks 540_1, 540_2), the designer has the choice of a trade-off between performance and energy consumption. The developer can make the choice to continue using traditional decoding approaches without a noticeable increase in performance. Alternatively, the designer may decide to spend more energy on a more complex decoding scheme (e.g., joint trellis decoding for joint decoding of both received bit streams), as described in more detail below.

6 illustrates an embodiment of a radio communications network 600. The radio communications network 600 supports legacy receivers. The representation of 6 corresponds to the radio communication network 100, as in 3 shown. The entire functionality enclosed by the dashed line, ie the functionality of the combiner C, the shared radio link 110, the decoding operation 1 and the decoding operation 2, for example at one or a plurality of receivers and the reconstruction of information B by the decoding operation 1 (corresponding to OP1 of 3 ) and the reconstruction of information A by the decoding operation 2 (corresponding OP2 from 3 ), is not available for legacy recipients. This functionality can only be implemented in advanced (proprietary) equipment, ie, advanced transmitters and/or one or more advanced receivers, as disclosed herein.

7 illustrates a plurality of directional radio links and a shared radio link for data uplink transmission in a radio communication network in which a mobile station MS (transmitter) is connected to two base stations BS1, BS2 via a shared link 110 and two directional links 120_1 and 120_2 . As indicated above, the shared connection 110 and the directional connections 120_1, 120_2 could be, for example, LTE and mmWave radio links, respectively, but could also be any other suitable standards, such as Wi-Fi (IEEE 802.11a/b/g/ ac/ad/n/af/etc.), Bluetooth, WiMAX, etc., can be used with different coding schemes. The above description regarding radio communication networks 100, 400, 500 and the concept of “network coding” also applies to the uplink radio link design of 7 , and for the sake of brevity, repetitions are omitted.

In the 7 The design shown is that of the classic “butterfly net” from 2 similar and particularly adapted for network coding. According to one embodiment, the transmitted bit streams received at the base stations BS1, BS2 can be channel decoded at each base station BS1, BS2. In this case, the bit stream sent over the shared radio link 110 and the bit stream sent over the first directional radio link 120_1 are channel decoded in the base station BS1, and the bit stream sent over the shared radio link 110 and the bit stream sent over the second directional radio link 120_2 become channel decoded at the second base station BS2.

According to a further embodiment, central processing, such as coordinated multipoint (CoMP) processing, may optionally be used to combine the signals received at both base stations BS1, BS2. In this case, joint decoding is performed based on at least one bit stream received at the first base station BS1 and at least one bit stream received at the second base station BS2. Typically, joint decoding can be performed on at least three received bit streams or on all received bit streams, as in 7 shown.

8A illustrates, by way of example, an exemplary radio communications network 800 and a transmitter and/or a receiver or channel decoder used therein. The transmitter, for example a mobile station MS transmitter, provides two message sources S1, S2 within the context described above. The message source S1 outputs the first bit stream a from bits a _i , and the message source S2 outputs the second bit stream b from bits b _i . The channel encoder 801, which corresponds to the channel encoder 501 of 5 can correspond, encodes the first bit stream a into a channel encoded first bit stream A. The optional channel encoder 802, which corresponds to the channel encoder 502 of 5 can correspond, can channel code the second bit stream b into the second channel coded bit stream B.

The e.g. channel-coded second bitstream B is then modified in the combiner C by applying an operation such as an EXCLUSIVE OR operation to the second (e.g. channel-coded) bitstream B and the first channel-coded bitstream A.

The first channel-coded bit stream A is then transmitted over a first propagation channel 810, which is the shared radio link 110 and the RAT1 propagation channel 510 5 may correspond to one or both base stations BS1 and BS2. Furthermore, the combined bit stream is transmitted via a second propagation channel 820, for example either the first directional radio link 120_1 and the RAT2 propagation channel 520_1 5 or the second directional radio link 120_2 and the RAT2 propagation channel 520_2 from 5 may correspond to a common channel decoder 850. The common channel decoder 850 may either be located in or associated with the first base station BS1 (and then operate jointly on the transmitted first bit stream received over the shared radio link 110 and on the transmitted second bit stream received over the first directional radio link 120_1 is received) or may be located in or associated with the second base station BS2 (and then operates jointly on the transmitted first bit stream received over the shared radio link 110 and on the transmitted combined bit stream received over the second directional radio link 120_2 or may be located at or associated with a central location to perform central processing including, for example, central channel decoding, for example CoMP processing. In this case can the common decoder 850 operate jointly on at least two or three or all transmitted bit streams which are transmitted via the shared radio link 110 (first propagation channel 810), the first directional radio link 120_1 (second propagation channel) and the second directional radio link 120_2 (in 8A not shown) are received as in 7 shown. In all cases, the common channel decoder 850 may output a first bitstream that is a reconstruction of the first bitstream a of the message source S1, and may output a second bitstream b that is a reconstruction of the second bitstream b of the message source S2. These bit streams a, b are directed to a single message sink 860 of a receiver, which can be located either in one of the base stations BS1 or BS2 or, in the CoMP case, at a central location.

In general, it may be possible, as in 8A As an example, the transmission of the encoded first bit stream and the combined bit stream is cross-switched so that the encoded first bit stream is sent first over the first propagation channel 810 and then over the second propagation channel 820, and the combined bit stream is sent first over the second propagation channel 820 and then is sent over the first propagation channel 810, and vice versa. As an example, the transmitter may optionally include a channel quality evaluation unit CQ, which is designed to evaluate the channel qualities of the propagation channels 810, 820, and may optionally include a selector or cross switch SW, which is designed to use the propagation channel with the poorer channel quality as the first propagation channel to select, and to select the propagation channel with the better channel quality as the second propagation channel.

The two cases referred to above (local channel decoding/processing, referred to here as “no CoMP”; central channel decoding/processing, referred to here as CoMP) are described in detail below. In the first case (i.e. no CoMP), independent channel decoders can be provided in the receivers (e.g. base stations BS1, BS2), and in the second case where the bit streams received at the multiple receivers (e.g. base stations BS1, BS2) are sent to a central location To be jointly channel decoded and further processed (i.e. CoMP), a common channel decoder may be provided to provide overall joint decoding.

Independent channel decoders (no CoMP)

The classic butterfly scheme, as in 2 and 3 illustrated, can be particularly adapted for a lossless or error-prone scenario, since it already shows important gains when both receivers want the same information A, B. That is, for example with reference to 7 and 8A If both base stations BS1, BS2 request the same information from the mobile station MS via both a directional radio link 120_1 or 120_2 (e.g. mmWave) and a shared radio link 110 (e.g. LTE or Wi-Fi), a typical butterfly scenario is envisaged. As an example, a scenario occurs during roaming between two base stations BS1, BS2 during the handover in which the mobile station MS wants to send the same information to these two different base stations BS1, BS2. In such a scenario, the first bitstream A and the second bitstream B may be sent to the two directional links 120_1 and 120_2, respectively, while the combined bitstream (e.g. using an EXCLUSIVE OR operation A ⊕ B) over the shared radio link 110 is sent. In this way, the mobile station MS does not have to handle directly which base station BS1, BS2 receives which information during the handover, but simply sends the information (e.g. the first bit stream A) to a base station on a directional radio link 120_1 and then suddenly switches to the base station BS2 by sending the second bit stream B on the other directional radio link 120_2. In the event that the base stations BS1 and BS2 do not strictly follow this procedure during handover, they can still obtain the remaining information by using the shared radio link 110, which transmits the combined bit stream, eg A ⊕ B. In this way, the robustness of the handover is increased and the probability of errors during a handover is reduced by sending the information that needs to be sent for a handover in RAT1 over the directional radio links 120_1 and 120_2 and the shared radio link 110 for backup and Error correction is used if necessary.

8B shows a block diagram illustrating a transmitter and receiver implementation that is not designed for CoMP operation. In short, the transmitter includes message sources S1 and S2 and channel encoders 801 and 802, as already in 8A shown. In 8B Two receivers (eg two base stations BS1, BS2) are provided, and each receiver includes a single channel decoder 850_1 and 850_2 and a single message sink 860_1 and 860_2.

While the first channel-encoded bitstream A is sent over the first propagation channel 810 and the combined bitstream is sent over the second propagation channel 820, as discussed above 8A explained, the third channel-coded bit stream B is sent via a third propagation channel 830, which is, for example, the second directional radio link 120_2 and the RAT2 propagation channel 520_2 of 5 can correspond.

In this example, channel decoders 850_1 and 850_2 may both be configured to include two independent channel decoders, one for decoding the received bitstream A and one for decoding the received bitstream B. In legacy equipment, only one of these two channel decoders will be available (e.g. In channel decoder 850_1 only the channel decoder works for the received bit stream A, and in channel decoder 850_2 only the decoder works for the received bit stream B). However, in advanced receivers (e.g., proprietary equipment), the channel decoder 850_1 can generate the received second bitstream B, for example by applying the EXCLUSIVE OR operation, and then also channel encode this bitstream to additionally obtain the restored second bitstream b, and the Channel decoder 850_2 can generate the received first bitstream A, for example by applying the EXCLUSIVE OR operation, and then also channel encode this bitstream to additionally obtain the restored second bitstream b. In this case, the individual message sinks 860_1 and 860_2 (which may be located in different remote receivers, such as in different base stations BS1, BS2) will each receive the complete information output of both message sources S1 and S2.

Note that each channel decoder 850_1 and 850_2 can also be implemented by a single channel decoder using common decoding based on, for example, a common trellis decoding scheme.

9 illustrates an example of error correction in a base station, eg base station BS2 (which includes the message sink 860_2) for the above scenario. Channel-coded transmitted bits B _i-1 , B _i , B _i+1 are received via the second directional radio link 120_2, which is connected, for example, to the third propagation channel 830 of 8B is associated. Furthermore, the channel-coded transmitted combined bits A _i-1 ⊕B _i-1 , A _i ⊕B _i , A _i+1 ⊕B _i+1 are received via the shared radio link 110, which is connected, for example, to the second propagation channel 820 in 8B is associated. It is assumed that an error occurs at bit B _i . In this case, the base station BS2 can use the combined bit A _i ⊕ B _i instead of B _i to obtain information about the erroneous bit B _i . That is, the shared radio link 110 is used for error correction, thereby improving the performance of the radio communication network in terms of throughput and latency.

Common Channel Decoder (CoMP)

The in 9 The error correction process illustrated as an example can also be applied to the case where the information received via the two base stations BS1, BS2 is channel decoded at a single central location, ie the CoMP case. When the first and second bit streams A, B, as received by the base stations BS1 and BS2, respectively, are sent to a central location for channel decoding (as in CoMP processing), both base stations BS1, BS2 no longer need the entire information process. In this case, in a lossless scenario, half the information would be enough. However, in a realistic and lossy scenario, this same design can still be used for error correction with the combined bit stream (e.g. A⊕B) sent over the shared radio link 110. For example, with renewed reference to 9 an error on B _i can be corrected with knowledge of A _i and knowledge of the combined bit (e.g. A _i ⊕B _i ) to obtain B _i = A _i ⊕(A _i ⊕B _i ). That is, most of the time, the entire shared information (ie, the combined bitstream) sent over the shared radio link 110 does not need to be channel decoded, but only when an error occurs on the transmitted bitstreams A or B, e.g the directional radio links 120_1, 120_2 are sent, the shared information (ie the bits of the combined bit stream) can be used for error correction.

In general, with reference to both scenarios described above (no CoMP and CoMP), the shared radio link 110, the first directional radio link 120_1 and the second directional radio link 120_2 do not need to have identical throughput rates (although identical throughput rates can be used, as described above in Reference to the classic butterfly net design 2 and 3 explained). In the case that, for example, the directional radio connections 120_1, 120_2 and the shared radio link have asymmetric (ie, different) throughput rates, the proposed combination of the encoded first bitstream A with the second bitstream b or B, for example using an EXCLUSIVE OR operation (or any other suitable operation). applied to all or part of the bit stream to be sent over the lower throughput radio link and to a part of the bit stream to be sent over the higher throughput radio link, while the remaining part of the bit stream to be sent over the radio link to be sent at higher throughput, is sent without modification. In this way, it is possible, for example, to protect a limited number of, for example, latency-critical parts of the bit stream from being sent over the radio connection with a higher throughput.

As an example, the first and second directional radio links 120_1, 120_2 may provide a higher throughput rate than the shared radio link 110. If the combined bitstream is sent over the shared radio link 110, in this case it would be with reference to the example of 9 possible to send only the combined bit A _i ⊕B _i to protect the bit B _i , while the combined bits A _i-1 ⊕B _i-1 and A _i+1 ⊕B _i+1 are not sent.

In addition, the first and second directional radio links 120_1, 120_2 and the shared radio link 110 do not even have to have the same capacity. That is, the shared radio link 110 may, for example, have a lower capacity than each of the first and second directional radio links 120_1, 120_2. The above disclosure about different throughput rates of these radio links applies identically to radio links with different capacities, although it is still possible to replace the most important parts of the bit stream sent over the higher capacity radio link with a combined bit stream sent over the lower capacity radio link Capacity is sent to protect.

Alternatively, it is also possible to combine several bits of the bit stream to be sent over the higher throughput rate radio link as the number of bits to be sent over the lower throughput rate radio link. This could be achieved by combining the bits of the bitstream to be sent over the higher throughput radio link with repeated bits of the bitstream to be sent over the lower throughput radio link. In this case, the repeated bits are preferably interleaved (i.e., the sequence order is changed according to a predetermined, e.g., quasi-random, interleaving scheme), for example, to produce different interleaving patterns. In general, in the case of asymmetric data rates, the bit stream of the radio link with the lower data rate can only be combined with a part of the bit stream of the radio link with the higher data rate.

As stated above, the first and second bit streams a, b refer to the two message sources S1, S2 (see 8th ) at least partially to the same message from a common news source S, see 2 , 3 , is sent. The following considers how the probability of errors can be minimized while the message data is sent over at least two radio links to the same receiver, for example base station BS1 or base station BS2 or a central location, where the message data transmitted over the at least three radio links 100 , 120_1 and 120_2 are sent, are decoded. Minimizing the probability of errors will result in less message data having to be resent, for example, through a data retransmission scheme such as ARQ or HARQ, thereby improving both throughput and latency in the radio communications network.

A simple way to derive a bitstream a, b from an initial bitstream representing the message to be sent is to simply divide the information encoded by the initial bitstream in half, so that the first bitstream a and the second bitstream b have an equal number of Bits a _i and b _i have.

For the example set out below, it can be assumed that a standard channel encoder is used to channel encode both bitstream a and bitstream b. So can with reference to 4 , 5 and 8A , 8B Channel encoders 401, 501, 801 and channel encoders 402, 502, 802 are exemplified by the channel encoder description below. However, it should be noted that other types of channel encoders may be used, including any type of channel encoder containing convolutional codes, block codes, turbo codes, low density parity check (LDPC) codes, Reed-Solomon codes, etc. use.

10 illustrates an exemplary convolutional channel encoder 1000. The channel encoder 1000 may provide a code rate of 1/2, meaning that for each bit a _i , two bits A1 _i and A2 _i are output to form the encoded bit stream A. If the channel encoder 1000 is used for channel coding of the second bit stream b, two bits B1 _i and B2 _i are output analogously for each bit b _i . These two encoded bitstreams A and B (i.e. (A1,A2) and (B1,B2)) are then sent over two radio links and channel decoding is performed on the received bitstreams to produce an estimated or restored bitstream a and an estimated or restored bitstream b to obtain. Channel decoding can be done, for example, using Viterbi decoding, such as that found in WLAN devices based on the IEEE 802.11 standards, also known as Wi-Fi.

As is clear to experts, the in 10 channel encoder shown is the (2,1,7) [133,171] ₈ convolutional channel encoder used in Wi-Fi.

However, according to various embodiments described herein, the channel coded bit streams A and B are not sent as such, but rather some form of, for example, network coding is used to send at least a portion of the coded information by combining the channel coded bit streams A, B, and by at least part of the coded bit streams A, B is replaced by a combined bit stream in order to be sent. For example, instead of sending (A1,A2) and (B1,B2), the same radio links and bandwidths could be used to send (A1,A2) and, for example, (B1⊕A1, B2⊕A2). This means that the coded bit stream (B1, B2) is replaced by the combined bit stream of, for example, (B1⊕A1, B2⊕A2). That is, for example, if the second radio link over which the bitstream is sent is less error prone, channel decoding will use the fact that the combined bitstream contains information about the encoded first bitstream A to correct some of the errors involved in the Decoding of the coded first bit stream (A1,A2) occurs.

In the example above, the combined bitstream was illustrated by (B1⊕A1, B2⊕A2). However, any other combination can be used, such as (A1,A2) and (B1, B2⊕A2) or (B1, B1⊕A1) or (B1, B1⊕A2) or (B1, B2⊕A1) or ( B2, B1⊕A1) or (B2, B1⊕A2) or (B2, B2⊕A1) or (B2, B2⊕A2). Another possible combination of coded bit streams A and B would be, for example, to use (A1,A2) for the coded first bit stream to be sent over the first radio link, and for example to use (B1,A2) for the combined bit stream to be sent via the second radio connection is to be sent. In this case, B2 is omitted but can be recovered from channel decoding because B2 is due to its generation by a channel encoder, e.g. the channel encoder 1000 of 10 , is redundant.

In the examples above, the channel-encoded first bitstream (A1,A2) is sent over the first radio link (which may be, for example, one of the directional radio links 120_1, 120_2), while the combined bitstream is sent over the second radio link (which is the shared radio link 110 could be). Clearly, however, the encoded bitstreams A and B are interchangeable in the above scheme, i.e., “A” can be replaced by “B” (i.e., A1 can be replaced by B1, and A2 can be replaced by B2), and “B” can be replaced by “A” (that is, B1 can be replaced by A1, and B2 can be replaced by A2).

Furthermore, it is proposed to evaluate the channel qualities of the at least two radio links (e.g. the shared radio link 110 and at least one of the first and second directional radio links 120_1, 120_2), and as a radio link over which the coded bit stream is sent (i.e. (A1 ,A2) or (B1,B2)), to select the radio link with the poorer channel quality, and to select the radio link with the better channel quality as the radio link over which the combined bit stream is sent. That is, as an example, if the second radio link (e.g. shared radio link 110) is better than the first radio link (e.g. one of the first or second directional radio links 120_1, 120_2), the combination of (A1, A2) sent via the first radio connection, and e.g. (B1, B2⊕A2), sent over the second radio connection, leads to a better decoding result than the reverse radio connection selection. In this context, a “better” radio link or better quality radio link may mean that this radio link has a higher SNR (signal-to-noise ratio) or a higher SINR (signal-interference-plus-noise ratio) or is less noisy.

In the event that the channel quality on the first radio link (e.g. on one of the directional radio links 120_1, 120_2) is better compared to the second radio link (e.g. the shared radio link 110), with reference to the example given above, the coded first Bit stream (A1, A2) can then be sent over the second radio connection, and for example (B1, B2⊕A2) can then be sent over the first radio connection. In both cases, the better quality radio link drives down the number of errors from the poorer quality radio link. As already in 8A cited as an example, it may generally be possible to cross-switch the transmission of the encoded first bitstream and the combined bitstream so that the encoded first bitstream is sent first over the first radio link and then over the second radio link, and the combined bitstream first over the second radio connection and then sent over the first radio connection, and vice versa. As an example, the transmitter may include a channel quality evaluation unit designed to evaluate the channel qualities of the radio links, and a selector or cross switch designed to select the one with the poorer channel quality as the first radio link and the one with the poorer channel quality as the second radio link to choose better channel quality.

As stated above, at least a portion of the first bitstream (ie, the first bitstream or portions thereof, such as a subset of the bits of the first bitstream) is coupled to at least a portion of the second bitstream (ie, the second bitstream or portions thereof, such as a subset of the bits of the second bit stream) combined. Some of the proposed mapping approaches of the first bitstream A_n ∋ (0,1),n = 0,1,... and the second bitstream B_n ∋ (0,1), n = 0,1, ... are in Table 1 (note that in Table 1 the notation changes slightly from A _i to A_n and from B _i to B_n). As shown in Table 1, this new connection mapping (or this so-called new bitstream combination) differs from the classic scheme of sending A_n on one radio link and B_n on another radio link. As stated above, A_n and B_n may represent the outputs of the PHY channel coding (e.g. the channel encoder 401, 501, 801 and 402, 502, 802 respectively, which may be further processed by a bit interleaver e.g. for quasi-randomization of the order of the bits and/or a puncturing stage designed to delete some of the encoded bits to modify the code rate). Table 1 Number of the proposed new mapping approach Radio connection 1 (e.g. directional mmWave connection, which is sent in different directions by two antennas, for example) Radio connection 2 (e.g. (quasi-) omnidirectional connection, such as an LTE connection) 1 A_n, n=0.1... (B_n⊕A_f(n)), n=0, 1,..., f(n) is any suitable interleaving function that modifies the order for the A_n bits 2 (A_(2n) ,A_(2n+1)), n = 0, 1... (B_(2n), B_(2n+1) ⊕A_f(2n + 1)), n=0, 1,..., f(n) is any suitable interleaving function that modifies the order for the A_n bits 3 (A_(2n),A_(2n+1)), n=0, 1... (B_(2n), A_f(2n)), n=0, 1,..., f(n) is any suitable interleaving function that modifies the order for the A_n bits 4 (A_(2n), A_(2n+1)), n=0, 1... (B_(2n), B_(2n)®A_f(2n)) , n=0, 1,..., f(n) is any suitable interleaving function that modifies the order for the A_n bits 5 (A_(2n), A_(2n+1)), (B_(2n+1), B_(2n+1) ⊕A_f( 2n+1)), n=0, 1,..., f(n) is any suitable nesting function that determines the order for the A_n bits modified n=0, 1... 6 (A_(2n), A_(2n+1)), n=0, 1... (B_(2n+1), B_(2n) ⊕A_f(2n )), n=0, 1,..., f(n) is any suitable interleaving function that modifies the order for the A_n bits 7 (B_n⊕A_n), n=0, 1,... A_n, n=0, 1,... 8th (B_(2n), B_(2n+1) ⊕A_f (2n + 1)), n=0, 1, ..., f (n) is any suitable interleaving function that modifies the order for the A_n bits (A_(2n),A_(2n+1)), n=0, 1,... 9 (B_(2n),A_f (2n)), n=0, 1, ..., f (n) is any suitable interleaving function that modifies the order for the A_n bits (A_(2n), A_(2n+1)), n=0, 1,... 10 (B_(2n), B_(2n) ⊕ A_f(2n)) , n=0, 1,... , f(n) is any suitable nesting function that modifies the order for the A_n bits (A_(2n), A_(2n+1)), n=0, 1,... 11 (B_(2n+1), B_(2n+1) ⊕A_f( 2n+1)), n=0, 1,..., f (n) is any suitable nesting function that determines the order for the A_n bits modified (A_(2n), A_(2n+1)), n=0, 1,... 12 (B_(2n+1), B_(2n)⊕+A_f(2n)), n = 0, 1, ..., f(n) is any suitable interleaving function that modifies the order for the A_n bits (A_(2n), A_(2n+1)), n=0, 1,... 13 (A_(2n), A_(2n+1)), n=0, 1,... (B_(n),A_f (n)), n=0, 1,..., f (n) is any suitable interleaving function that modifies the order for the A_n bits 14 (A_(2n), A_(2n+1)), n=0, 1,... . (B_(n), B_(n) ⊕+A_f(n)), n=0, 1,..., f (n) is any suitable interleaving function that modifies the order for the A_n bits 15 (B_(2n),A_f (2n)), n=0, 1,..., f (n) is any suitable interleaving function that modifies the order for the A_n bits (A_(2n), A_(2n+1)), n=0, 1,... 16 (B_(n), B_(n)⊕+A_f(n)) , n =0, 1, ... , f(n) is any suitable nesting function that modifies the order for the A_n bits (A_(2n), A_(2n+1)), n=0, 1,...

In summary, disclosed here is an approach to channel encode and decode data sent over two separate radio links using e.g. network coding techniques, e.g. decoding them together, which can reduce the number of errors without adding any data overhead compared to a scenario where the data sent over the two separate radio links would be decoded independently. This approach can be used to minimize the amount of errors when the channel decoder only has access to two of the radio links, while at the same time being able to recover all received information from any two radio links. In this way, not only could errors from any radio link be ignored (since each radio link can be considered redundant), but it is also possible to use only two available radio links e.g. at a single base station to transmit the entire information with typically fewer errors than in the classic case. Further, from the bitstream mapping examples of Table 1, it is noted that either the EXCLUSIVE OR operation can be applied to the entire channel-encoded first bitstream or to only a portion of the channel-encoded first bitstream. Similarly, the EXCLUSIVE OR encoding operation can be applied to the be applied to the entire (eg channel-coded) second bit stream or only to a part of the (eg channel-coded) second bit stream.

If the message output from the single source S is not to be sent to a central location for channel decoding, but is to be decoded at each base station BS1 and BS2 (i.e. the restored source bit streams a and b are required to be sent at each individual base station BS1 or BS2 to be restored), the hybrid design as described above should be the best adapted. That is, as an example, the encoded first bitstream (A1, A2) may be sent over the weaker shared radio link 110 (e.g. Wi-Fi, LTE, etc.), and the first and second combined bitstreams, e.g. (B1, B2⊕ A2) and (B1⊕A1, B2) can be sent over the better directional radio links 120_1 and 120_2, respectively. Note that the directional radio links 120_1 and 120_2 are typically the higher throughput radio links than the shared radio link 110_1. This hybrid butterfly scenario is used as an example in 11 illustrated. It should be noted that 11 a specific example of the in 7 general scenario illustrated.

According to a further possibility, the radio link with the higher throughput (e.g. one or both of the directional radio links 120_1, 120_2) could also be used to send a bit stream that is partially or entirely channel-uncoded, and delay-critical sections would be protected, e.g. by the lower throughput shared radio link (e.g., shared radio link 110, such as Wi-Fi, LTE, etc.).

1. (i) Senden des codierten ersten Bitstroms (A1,A2) über die erste Funkverbindung und Senden des (nicht-codierten) zweiten Bitstroms (b_n,b_n) über die zweite Funkverbindung, wobei b_n den Eingängen des zweiten Kanalcodierers 402, 502, 802 entspricht (es ist zu beachten, dass in diesem Fall die zweite Funkverbindung keine Kanalcodierung und auch keine Netzcodierung verwendet); oder
2. (ii) Senden des codierten ersten Bitstroms (A1,A2) über die erste Funkverbindung und Senden des (nicht-codierten) ersten Bitstroms (a_n,b_n) über die zweite Funkverbindung, wobei a_n und b_n den Eingängen der jeweiligen ersten und zweiten Kanalcodierer 401, 501, 801 und 402, 502, 802 entsprechen (es ist zu beachten, dass in diesem Fall die zweite Funkverbindung keine Kanalcodierung und auch keine Netzcodierung verwendet).

According to yet another possibility, transmission without any network coding may even be possible, such as:

1. (i) sending the coded first bit stream (A1, A2) over the first radio link and sending the (non-coded) second bit stream (b_n, b_n) over the second radio link, where b_n corresponds to the inputs of the second channel encoder 402, 502, 802 (it should be noted that in this case the second radio connection does not use channel coding or network coding); or
2. (ii) sending the coded first bit stream (A1, A2) over the first radio link and sending the (non-coded) first bit stream (a_n, b_n) over the second radio link, where a_n and b_n correspond to the inputs of the respective first and second channel encoders 401 , 501, 801 and 402, 502, 802 (note that in this case the second radio connection does not use channel coding or network coding).

Similarly, the above transmission schemes could also be applied to the first radio link without network coding, and some different combinations among them can then be applied to both radio links (i.e. in the above transmission schemes, "A" can be replaced by "B", and "B" can be replaced by “A”).

Various receiver architectures are possible for operation in a radio communications network, as described herein. The receiver architecture can be chosen depending on, for example, what information was sent, what information is desired, and the quality of the radio connections over which the information is sent.

At least two bit streams, i.e. at least a first bit stream and a second bit stream, are always received from a base station BS1 or from two or more base stations BS1, BS2, ..., etc.

In all cases, a receiver designed to operate in a radio communications network as described herein may include channel decoder equipment. The receiver may include a first receiver branch configured to receive a first bitstream, the received first bitstream being a reconstruction of the channel-coded first bitstream transmitted over the first radio link of the radio communications network. The receiver may further comprise a second receiver branch configured to receive a combined bit stream, the received combined bit stream being a reconstruction of the combined bit stream transmitted over the second radio link of the radio communications network, the transmitted combined bit stream being a combination of the channel encoded first bitstream with the second bitstream, and wherein the first bitstream and the second bitstream represent a message.

Furthermore, the receiver may comprise a channel decoder which is designed for channel decoding of the received first bit stream and the received combined bit stream. According to a first possibility, the received first bit stream and the received combined bit stream are channel decoded at each base station, ie the complete information of the message is to be restored at each base station (local processing, ie no CoMP). In this case, a single channel decoder for decoding the received first bit stream and the received combined bit stream is implemented at each base station BS1, BS2, ..., as already explained above. This single channel decoder can perform common trellis channel decoding of the received first bit stream and the received combined bit stream.

This case of channel decoding localized at the base station (i.e. “local processing”) is in the middle part of 12 illustrated. In general, each base station BS1, BS2 includes an RF stage 1201, 1202, which is designed to receive, down-convert and digitize the signals received over the at least two radio links to form the first received bit stream 1211 or 1212 and the received combined one Base station 1221 or 1222 to be generated. The two received bit streams 1211, 1221 are channel decoded together by a first channel decoder 1231 arranged at the first base station BS1, and the two received bit streams 1212, 1222 are channel decoded together by a second channel decoder 1232 arranged at the second base station BS2 .

If the received bit streams 1211, 1221 and 1212, 1222 need to be channel decoded at a single location (“central processing” or CoMP), some options for a receiver and channel decoding architecture are feasible. As an example, as in the upper part of 12 As illustrated, a common receiver 1240 may be provided at a single location and, for example, CoMP may be used. The common receiver 1240 may, for example, be provided with first and second network coding determination stages 1241 and 1242, first and second buffers 1243 and 1244, first and second decoders 1245 and 1246, and a common channel decoder 1247.

The network coding determination stages 1241, 1242 determine whether each of the received first bit stream 1211 or 1212 and the received second bit stream 1221 or 1222 are network encoded or not. If the second received bit stream 1221 or 1222 is a received combined bit stream as explained above, the respective network coding determination stage 1241 or 1242 determines the network coding. In this case, the received combined bit stream 1221 or 1222 may be stored in the respective buffer 1243 or 1244, and the first received bit stream 1211 or 1212 may be channel decoded in the respective channel decoder 1245 or 1246. Only in the event that an error occurs during decoding of the received first bit stream 1211 or 1212 will the received combined bit stream 1221 or 1222 - or the respective parts thereof where the error occurred - be used for error correction. In this case, the common channel decoder 1247 can be used to channel decode the necessary portions of the received combined bit stream 1221, 1222 to correct the errors of the received first bit stream 1211 or 1212, respectively.

According to another receiver architecture, the common receiver 1240, as illustrated above, is not located at a single location but is duplicated at each base station BS1, BS2. It is also possible to apply the above-described scheme of using a buffer 1243, 1244 to temporarily store redundant information (e.g. parity bits) from the received combined bit stream for local processing at each base station BS1, BS2. In this case, the first base station BS1 includes the network coding determination stage 1241, the buffer 1243, the channel decoder 1245 and the channel decoder 1247 for common channel decoding in the event that an error occurs in the channel decoder 1245 (note that the channel decoder 1247 is then no longer a common channel decoder, but a single, local channel decoder). The second base station BS2 may then include the network coding determination stage 1242, the buffer 1244, the channel decoder 1246 and a replica of the channel decoder 1247 designed to operate in the event that an error in the channel decoder 1246 occurs.

In other words, the upper part of illustrates 12 a receiver architecture suitable for central processing, e.g. CoMP, but can also be interpreted (by replacing the common channel decoder 1247 with two local channel decoders 1247) to illustrate a receiver architecture suitable for local processing, e.g. non-CoMP , suitable is.

The lower part of 12 illustrates yet another possibility for implementing a receiver 1260. In this case, the receiver 1260 is provided at a single location that is not associated with one of the first and second base stations BS1 or BS2. The receiver 1260 may include a common channel decoder 1261. The common channel decoder 1261 can operate on the received first bit stream 1211 and the received combined bit stream 1221 of the first base station BS1 and on the received first bit stream 1212 and the received combined bit stream 1222 of the second base station BS2. The channel decoder 1261 can, for example, perform joint decoding with the at least two best radio connections. That is, channel decoding may be performed on data received over the shared link and at least one of the directional radio links 120_1 or 120_2. For example, for legacy transmitters and/or receivers, the common channel decoder 1261 may channel decode the bit streams received over the first and second directional radio links 120_1, 120_2 if these bit streams have been channel encoded according to the standard coding scheme (e.g. from RAT1).

It should be noted that it is the common channel decoding approach, as shown in the lower part of 12 illustrates, allows all but two received bit streams to be completely skipped in order to decode the complete information together (or alternatively, a third or more of the received bit streams to be used to further drive the amount of error down).

13 is a representation of a radio communications network indicating the network coding approach for a mobile station-to-mobile connection. 13 illustrates an example radio communications network 1300. A network coding solution in a UE-to-UE design is considered. More specifically, a first mobile station UE1 sends a coded first bit stream on the uplink over a first directional radio link 120_1. On the other hand, a UE2 sends a first coded bit sequence on the uplink over a second directional radio link 120_2. The base station BS (eNodeB) receives the respective coded first bit stream and sends a combined bit stream on the downlink via the shared radio connection 110 (e.g. LTE, Wi-Fi, etc.). Then each mobile station UE1, UE2 can decode the message sent by the other UE by combining the first bit stream received by the other UE with the data of the combined bit stream sent by the other UE over the shared radio link. is decoded. The first and second directional radio links 120_1, 120_2 can thus be used for next transmissions, while the shared radio link 110 (e.g. LTE, Wi-Fi, etc.) sends the combined bit stream, e.g. the EXCLUSIVE OR data, as in 13 illustrated.

Performance evaluation simulations were performed to verify the feasibility of using network coding in a multiple radio link scenario as described herein. 14 illustrates an exemplary implementation of two convolutional channel encoders 1401, 1402 configured to channel encode the first bit sequence a output from the first message source S1 and the second bit sequence b output from the second message source S2. Here, as an example, the first and second bitstreams a and b are derived simply by dividing the information of the message (i.e. the bitstream output from the single message source S) in half, so that the same number of bits a ₁ and bits b ₁ of the first bit stream a and the second bit stream b, respectively, are obtained. Note that channel encoders 1401, 1402 are exemplary specific implementations of channel encoders 401, 402; 501, 502; 801, 802 are as described here.

For example, each channel encoder 1401, 1402 has a constraint length of 7 and is the channel encoder found in WLAN products based on IEEE 802.11 standards, used here with a rate R = k/n = 1/2. To improve error protection, a (7,[133,171] ₈ ) convolution code was chosen (ie a constraint length of 7 with generator polynomials 133 ₈ and 171 ₈ ), which, for example, maximizes the maximum distance between codewords. [133,171] in octal numbers corresponds to [1011011,1111001] in binary numbers, as in 14 can be recognized, which shows the convolution decoders 1401, 1402.

The exemplary combiner, as in 14 illustrated uses network coding scheme number 2 in Table 1. That is, when applied to the block image of 8B (A_ (2n),A_ (2n+1)), n = 0, 1, ... is sent over the first radio link 810, and (B_(2n),B_(2n+1)⊕A_(2n+1 ) ), n = 0, 1, ... is sent via the second radio connection 820. Note that network coding scheme number 2 is a representative of the group of network coding schemes in which at most (or e.g. exactly) every other bit of the combined bitstream is generated by performing EXCLUSIVE-OR processing on the channel-encoded first bitstream and the second bitstream is used while the remaining bits of the combined bitstream are not generated using an EXCLUSIVE OR operation. How stated above, these remaining bits can be, for example, uncombined coded bits B1 _i or B2 _i or, for example, even uncombined uncoded bits b _i .

The bit streams received via both radio connections 810, 820 were decoded using common trellis decoding, in which both connections are decoded simultaneously. For this purpose, it was assumed that the number of memory elements of both encoders 1401, 1402 was added, and two bits of input information were assumed for each trellis transition. Decoding is done by a (2,1,7) Viterbi decoder.

15 illustrates the bit error rate (BER) versus Eb/No of the second radio link 820 (over which the combined bit stream is sent). The BER is used in the simulations based on the specific channel encoder 1401, 1402 and combiner C implementation 14 receive. The simulations were performed on an AWGN (additive white Gaussian noise) channel using BPSK (binary phase shift keying) modulation and Eb/No = 1 dB of the first radio link 810.

How out 15 As can be seen, the BER of the averaged uncoded radio link 1 (here refers to the radio link 810) and uncoded radio link 2 (here refers to the radio link 830) as well as the BER of the averaged convolutionally coded radio link 1 (here refers to the radio link 810) and Convolution-coded radio connection 2 (here refers to radio connection 830) is significantly worse than the BER of convolution-coded radio connection 1 (here refers to radio connection 810) and network-coded radio connection 2 (here refers to radio connection 820). More specifically, the simulations show that channel decoding is as good as if the weaker radio link had the same capacity as the better radio link. Arguably this couldn't be better than this, which is the best possible performance achievable with good convolutional encoded radio links.

EXAMPLES

The following examples include further embodiments.

Example 1 is a method for processing a message to be transmitted in a radio communications network, comprising: channel coding a first bit stream representing a message; combining at least a portion of the channel-encoded first bitstream with at least a portion of a second bitstream to generate a combined bitstream, which second bitstream at least partially represents the message; wherein the channel-coded first bit stream is designed to be sent over a first radio link of the radio communications network, and the combined bit stream is designed to be sent over a second radio link of the radio communications network.

In Example 2, the subject matter of Example 1 may optionally include that the radio communications network is a heterogeneous wireless network comprising a first radio access technology and a second radio access technology, and that the first radio link is a radio link of the first radio access technology, and the second radio link is a radio link of the second radio access technology.

In Example 3, the subject matter of any of Examples 1 to 2 may optionally include one of the first radio link and the second radio link being a quasi-omnidirectional radio link and the other radio link being a directional radio link.

In Example 4, the subject matter of any of Examples 1 to 3 may optionally include: evaluating the channel qualities of the two radio links; and
Select the one that has the poorer channel quality as the first radio connection and select the one that has the better channel quality as the second radio connection.

In Example 5, the subject matter of any of Examples 1 to 4 may optionally include: cross-switching the transmission of the coded first bitstream and the combined bitstream such that the coded first bitstream is configured to be sent over the second radio link and the combined bitstream is configured to be sent over the first radio connection.

In Example 6, the subject matter of any of Examples 1 to 5 may optionally include channel-coding the second bit stream.

In Example 7, the subject matter of any of Examples 1 to 6 may optionally include combining using EXCLUSIVE-OR processing on at least the portion of the channel-encoded first bitstream and at least the portion of the second bitstream.

In Example 8, the subject matter of Example 7 may optionally include generating at most every other bit of the combined bitstream using exclusive-or processing on the channel-encoded first bitstream and the second bitstream.

In Example 9, the subject matter of any of Examples 1 to 8 may optionally include combining using rateless coding of the channel-encoded first bitstream and the second bitstream.

In Example 10, the subject matter of any of Examples 1 to 9 may optionally include combining using Raptor encoding of the channel-encoded first bitstream and the second bitstream.

In Example 11, the subject matter of any of Examples 1 to 10 may optionally include the first bitstream and the second bitstream being derived from a single bitstream representing the message.

In Example 12, the subject matter of Example 11 may optionally include the bits included in the second bit stream being redundant bits of the bits included in the first bit stream.

Example 13 is a method for encoding data in a radio communications network, comprising methods: channel encoding a first bit stream representing a message; modifying a second bitstream that at least partially represents the message by combining bits thereof with bits of the channel-encoded first bitstream; wherein the channel-coded first bit stream is designed to be sent over a first radio link of the radio communications network, and the combined bit stream is designed to be sent over a second radio link of the radio communications network.

In Example 14, the subject matter of Example 13 may optionally include that the radio communications network is a heterogeneous wireless network comprising a first radio access technology and a second radio access technology, and that the first radio link is a radio link of the first radio access technology, and the second radio link is a radio link of the second radio access technology.

Example 15 is a method for channel decoding in a radio communications network, comprising methods: receiving a first bitstream, the received first bitstream being a reconstruction of a channel-encoded first bitstream transmitted over a first radio link of the radio communications network; Receiving a combined bit stream, the received combined bit stream being a reconstruction of a combined bit stream sent over a second radio link of the radio communications network, the transmitted combined bit stream being a combination of at least a portion of the channel-coded first bit stream with at least a portion of the second bit stream, wherein the first bitstream and the second bitstream represent a message; and channel decoding the received first bitstream and the received combined bitstream.

In Example 16, the subject matter of Example 15 may optionally include performing a common trellis channel decoding of the received first bitstream and the received combined bitstream.

In Example 17, the subject matter of any of Examples 15 to 16 may optionally include: buffering the received combined bit stream; and using the buffered combined bitstream for channel decoding only in the event that a decoding error occurs in channel decoding of the received first bitstream.

In Example 18, the subject matter of Examples 15 to 17 may optionally include at least one of the received first bitstream and the received combined bitstream being transmitted over a shared radio link and being received at both a first base station and a second base station; the other from the received first bit stream and the received combined bit stream is sent over a first directional radio link and is received only at the first base station; and channel decoding is performed at a central location based on the bit streams received over the shared radio link and the bit stream received over the first directional radio link.

In Example 19, the subject matter of Example 18 may optionally include a third bit stream being transmitted over a second directional radio link and received only at the second base station; and the channel decoding is further performed at the central location based on the bit streams received over the second directional radio link.

Example 20 is a transmitter of a radio communications network comprising: a first channel encoder configured to channel encode a first bit stream representing a message; a combiner configured to combine at least a portion of the channel-encoded first bitstream with at least a portion of a second bitstream, the second bitstream at least partially representing the message, the combiner generating a combined bitstream; a first transmitter branch that transmits the channel-coded first bit stream over a first radio link of the radio communication network; and a second transmitter branch that transmits the combined bit stream over a second radio link of the radio communication network.

In Example 21, the subject matter of Example 20 may optionally include that the radio communications network is a heterogeneous wireless network comprising a first radio access technology and a second radio access technology, and that the first radio link is a radio link of the first radio access technology, and the second radio link is a radio link of the second radio access technology.

In Example 22, the subject matter of Examples 20 to 21 may optionally include one of the first radio link and the second radio link being a quasi-omnidirectional link and the other radio link being a directional radio link.

In Example 23, the subject matter of Examples 20 to 22 may optionally further comprise: a channel quality evaluation unit configured to evaluate the channel qualities of two radio links; and a selector designed to select as the first radio connection the one with the poorer channel quality and as the second radio connection to select the one with the better quality.

In Example 24, the subject matter of Examples 20 to 23 may optionally include that the selector is configured to cross-switch the transmission of the coded first bitstream and the combined bitstream so that the coded first bitstream is sent over the second radio link and the combined base station over the first radio connection is sent.

In Example 25, the subject matter of Examples 20 to 24 may optionally further comprise a second channel encoder configured to channel encode the second bit stream.

In Example 26, the subject matter of Examples 20 to 25 may optionally include the combiner comprising: an EXCLUSIVE-OR stage included in the combiner, the EXCLUSIVE-OR stage being configured to at least the portion of the channel-encoded first bitstream and to process at least part of the second bit stream.

Example 27 is channel encoder equipment for operation in a radio communications network, comprising: a first channel encoder configured to channel encode a first bit stream representing a message; a combiner configured to modify a second bitstream that at least partially represents the message by combining bits of the second bitstream with bits of the channel-encoded first bitstream; wherein the channel-coded first bit stream is designed to be sent over a first radio link of the radio communications network, and the combined bit stream is designed to be sent over a second radio link of the radio communications network.

In Example 28, the subject matter of Example 27 may optionally include that the radio communications network is a heterogeneous wireless network that includes a first radio access technology and a second radio access technology, and that the first radio link includes a radio link of the first radio access technology, and the second radio connection is a radio connection of the second radio access technology.

In Example 29, the subject matter of Example 27 may optionally include the combiner comprising an EXCLUSIVE OR stage configured to process at least a portion of the channel-encoded first bitstream and at least a portion of the second bitstream.

Example 30 is channel decoder equipment for operation in a radio communications network, comprising: a first receiver branch configured to receive a first bitstream, the received first bitstream being a reconstruction of a channel-encoded first bitstream transmitted over a first radio link of the radio communications network ; a second receiver branch configured to receive a combined bit stream, the received combined bit stream being a reconstruction of a combined bit stream transmitted over a second radio link of the radio communications network, the transmitted combined bit stream being a combination of at least a portion of the channel-coded first bit stream with at least a portion of a second bit stream; wherein the first bitstream and the second bitstream represent a message; and a channel decoder configured for channel decoding of the received first bit stream and the received combined bit stream.

In Example 31, the subject matter of Example 30 may optionally include that the channel decoder is configured to perform common trellis channel decoding of the received first bitstream and the received combined bitstream.

In Example 32, the subject matter of Examples 30 to 31 may optionally further comprise a buffer configured to buffer the received combined bit stream; wherein the channel decoder is configured to use the buffered combined bitstream for channel decoding in the event that a decoding error occurs in channel decoding of the received first bitstream.

In Example 33, the subject matter of Examples 30 to 32 may optionally include at least one of the received first bitstream and the received combined bitstream being transmitted over a shared radio link and being received at both a first base station and a second base station, the another of the received first bit stream and the received combined bit stream is transmitted over a first directional radio link and received only at the first base station; and that the channel decoder is located at a central location and is adapted to perform channel decoding based on the bit streams received over the shared radio link and the bit stream received over the first directional radio link.

In Example 34, the subject matter of Example 33 may optionally include a third bit stream being transmitted over a second directional radio link and received only at the second base station; and that channel decoding is further performed at the central location based on the bit streams received over the second directional radio link.

Although specific embodiments and examples have been illustrated and described herein, it will be apparent to those skilled in the art that various alternative and/or equivalent implementations may be employed for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the embodiments and examples described herein. Therefore, this invention is intended to be limited only by the claims and the equivalents thereof.

Claims (23)

A method of processing a message to be transmitted in a radio communications network, the method comprising: channel coding a first bit stream representing a message; combining at least a portion of the channel-encoded first bitstream with at least a portion of a second bitstream by applying an EXCLUSIVE OR operation to the two bitstreams to generate a combined bitstream, the second bitstream at least partially representing the message; wherein the channel-coded first bit stream is designed via a first radio connection of the radio communication network, and the combined bit stream is designed to be sent via a second radio connection of the radio communication network. Procedure according to Claim 1 , in which the radio communication network is a heterogeneous wireless network that includes a first radio access technology and a second radio access technology, and in which the first radio connection is a radio connection of the first radio access technology, and the second radio connection is a radio connection of the second radio access technology. Procedure according to Claim 1 or 2 , in which one of the first radio link and the second radio link is a quasi-omnidirectional radio link, and the other radio link is a directional radio link. Method according to one of the preceding claims, further comprising: Evaluating the channel qualities of the two radio connections; and Selecting the one that has the poorer channel quality as the first radio connection and selecting the one that has the better channel quality as the second radio connection. Method according to one of the preceding claims, further comprising: Cross-switching the transmission of the coded first bitstream and the combined bitstream such that the coded first bitstream is configured to be sent over the second radio link and the combined bitstream is configured to be sent over the first radio link. Method according to one of the preceding claims, in which the second bit stream is channel coded. Method according to one of the preceding claims, in which at most every second bit of the combined bit stream is generated using exclusive-or processing on the channel-coded first bit stream and the second bit stream. A method according to any preceding claim, wherein the first bitstream and the second bitstream are derived from a single bitstream representing the message. Procedure according to Claim 8 , in which the bits contained in the second bit stream are redundant bits of the bits contained in the first bit stream. Method for encoding data in a radio communications network, the method comprising: channel encoding a first bit stream representing a message; modifying a second bitstream that at least partially represents the message by combining bits of the second bitstream with bits of the channel-encoded first bitstream by applying an EXCLUSIVE OR operation to the two bitstreams; where the channel-coded first bit stream is designed to be sent over a first radio link of the radio communications network, and the combined bit stream is designed to be sent over a second radio link of the radio communications network. Procedure according to Claim 10 , in which the radio communication network is a heterogeneous wireless network that includes a first radio access technology and a second radio access technology, and in which the first radio connection is a radio connection of the first radio access technology and the second radio connection is a radio connection of the second radio access technology. A method for channel decoding in a radio communications network, the method comprising: receiving a first bit stream, the received first bit stream being a reconstruction of a channel-encoded first bit stream sent over a first radio link of the radio communications network; Receiving a combined bitstream, the received combined bitstream being a reconstruction of a combined bitstream transmitted over a second radio link of the radio communications network, the transmitted combined bitstream combining at least a portion of the channel-encoded first bitstream with at least a portion of the second bitstream by applying an EXCLUSIVE OR operation on the two bitstreams, where the first bitstream and the second bitstream represent a message; and channel decoding the received first bitstream and the received combined bitstream. Procedure according to Claim 12 , in which a common trellis channel decoding of the received first bit stream and the received combined bit stream is carried out. Procedure according to Claim 12 or 13 , further comprising: buffering the received combined bit stream; and using the buffered combined bitstream for channel decoding in the event that a decoding error occurs in channel decoding of the received first bitstream. Procedure according to one of the Claims 12 until 14 , wherein at least one of the received first bit stream and the received combined bit stream is transmitted over a shared radio link and is received at both a first base station and a second base station; the other of the received first bit stream and the received combined bit stream is transmitted over a first directional radio link and is received only at the first base station; and channel decoding is performed at a central location based on the bitstreams received over the shared radio link and the bitstream received over the first directional radio link. Procedure according to Claim 15 , in which a third bit stream is transmitted over a second directional radio link and received at the second base station; and the channel decoding is further performed at the central location based on the bit streams received over the second directional radio link. Transmitter of a radio communication network, comprising: a first channel encoder configured to channel encode a first bit stream representing a message; a combiner configured to combine at least a portion of the channel-encoded first bitstream with at least a portion of a second bitstream by applying an EXCLUSIVE OR operation to the two bitstreams, the second bitstream at least partially representing the message, the combiner a combined bitstream generated; a first transmitter branch that transmits the channel-coded first bit stream over a first radio link of the radio communication network; and a second transmitter branch that sends the combined bit stream via a second radio connection of the radio communication network. Channel after Claim 17 , further comprising: a channel quality evaluation unit designed to evaluate the channel qualities of two radio links; and a selector designed to select as the first radio connection the one with the poorer channel quality and as the second radio connection to select the one with the better quality. Channel encoder equipment for operation in a radio communications network, comprising: a first channel encoder configured to channel encode a first bit stream representing a message; a combiner configured to modify a second bit stream that at least partially represents the message by combining bits of the second bit stream with bits of the channel-encoded first bit stream by applying an EXCLUSIVE OR operation to the two bit streams; where the channel-coded first bit stream is designed to be sent over a first radio link of the radio communications network, and the combined bit stream is designed to be sent over a second radio link of the radio communications network. Channel encoder equipment Claim 19 , in which the combiner comprises an EXCLUSIVE OR stage designed to process at least a portion of the channel-coded first bitstream and at least a portion of the second bitstream. Channel decoder equipment for operation in a radio communications network, comprising: a first receiver branch configured to receive a first bitstream, the received first bitstream being a reconstruction of a channel-encoded first bitstream transmitted over a first radio link of the radio communications network; a second receiver branch configured to receive a combined bit stream, the received combined bit stream being a reconstruction of a combined bit stream transmitted over a second radio link of the radio communications network, the transmitted combined bit stream being a combination of at least a portion of the channel-coded first bit stream with at least a portion of a second bit stream by applying an EXCLUSIVE OR operation to the two bit streams; wherein the first bitstream and the second bitstream represent a message; and a channel decoder configured for channel decoding of the received first bit stream and the received combined bit stream. Channel decoder equipment Claim 21 , in which the channel decoder is designed to carry out a common trellis channel decoding of the received first bit stream and the received combined bit stream. Channel decoder equipment Claim 21 or 22 , further comprising: a buffer configured to buffer the received combined bit stream; wherein the channel decoder is configured to use the buffered combined bitstream for channel decoding in the event that a decoding error occurs in channel decoding of the received first bitstream.

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