CN109525371B - Method and node for equal error protection in wireless communication system using adaptive hierarchical modulation - Google Patents

Abstract

A method (700) in a sender (110), a method (900) in a sender (110), a receiver (120) and a receiver (120) for multiplexing data streams (130-1,130-2) are disclosed by providing a dynamic stream-to-marker mapping. The method (700) comprises: transmitting (701) data over a plurality of data streams (130- < 1 >, 130- < 2 >); obtaining (702) a channel quality estimate; selecting (703) a data stream (130- < 1 >, 130-2) based on said obtained (702) channel quality estimate; determining (704) a modulation scheme (400); forming (705) a binary marker (420) and mapping each bit in the marker (420) with the selected (703) data stream (130-; determining (706) the binary flag (420) by collecting bits (b1, b2, …, bn) from the data stream (130-; -selecting (707) constellation points (410) in the determined (704) modulation scheme (400) in accordance with the binary flag (420); and transmitting (708) data characterizing the selected (707) constellation point (410) in a time-frequency resource element.

Description

Method and node for equal error protection in wireless communication system using adaptive hierarchical modulation

Technical Field

Implementations described herein relate generally to a method in a transmitter, a method in a receiver, and a receiver. In particular, a mechanism is described herein for transmitting multiple independent data streams in parallel by providing dynamic stream-to-tag mapping; effectively sharing the same physical resources while providing a similar level of error protection for the transmitted data streams.

Background

User Equipment (UE) (also referred to as a receiver), a mobile station, a wireless terminal, and/or a mobile terminal is capable of communicating wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system or a wireless communication network. Communication may be between, for example, multiple UEs, between a UE and a wire-connected telephone, and/or between a UE and a server through a Radio Access Network (RAN) and possibly one or more core networks. Wireless communications may include various communication services such as voice, messaging, packet data, video, broadcast, and so on.

The UE/receiver may also refer to a mobile phone, a cellular phone, a tablet or a laptop with wireless capabilities, etc. A UE herein, such as a portable, pocket storable, handheld, computer containing, or vehicle mounted mobile device, is capable of communicating voice and/or data with another entity, such as another UE or a server, via a wireless access network.

A wireless communication system may include a plurality of Transmission Points (TPs) for communicating with any UE over a radio frequency operating air interface within a range of the TPs. Accordingly, a plurality of UEs within a specific geographical area may communicate through any TP within the range of any TP of the wireless communication system.

Sometimes, a wireless communication system covers a geographical area which may be divided into cell areas, wherein each cell area is served by a Transmission Point (TP) or a radio network node, e.g. a base station, a Radio Base Station (RBS) or a Base Transceiver Station (BTS), which in some networks may be referred to as "eNB", "eNodeB", "NodeB" or "B node", depending on the technology and/or terminology used.

Sometimes, the word "cell" may be used to denote the TP/radio network node itself. However, in normal terminology, a cell may also be used to denote a geographical area where radio coverage is provided by a TP/radio network node located at a base station site. One TP/radio network node at the base station site may serve one or several cells. A TP/radio network node may communicate over a radio frequency operated air interface with any UE within range of the TP/radio network node. Furthermore, in some embodiments, in some wireless communication systems, multiple TPs may serve one cell.

In some radio access networks, such as the Universal Mobile Telecommunications System (UMTS), a plurality of TP/radio network nodes may be connected to a Radio Network Controller (RNC) by, for example, landlines or microwave. The RNC, sometimes referred to as a Base Station Controller (BSC), such as in GSM, may supervise and coordinate various activities of the various radio network nodes connected thereto. GSM is an abbreviation for global system for mobile communications (formerly: mobile expert group).

In third generation partnership project (3GPP) Long Term Evolution (LTE)/LTE-advanced, radio network nodes (which may refer to eNodeBs or eNodeBs) may be connected to one or more core networks, such as radio access gateways, through a gateway.

Future wireless communication systems must face the need for higher aggregate data rates while still providing reliable communication to many concurrent users and applications. Such high data rates are achieved by more and more efficiently utilizing the physical resources of the channel.

Consider a wireless communication system in which a service area is covered by a network of multiple TPs or wireless network nodes interacting with UEs present in the area to perform communication and coordination tasks. Such a network is commonly referred to as a RAN as described above.

Each UE may interact with one or more TPs, and vice versa. The unidirectional wireless link from the TP to the UEs may be referred to herein as a Downlink (DL), a downstream link, or a forward link, and the unidirectional wireless link from the UE to the TP may be referred to as an Uplink (UL), an upstream link, or a reverse link.

In Frequency Division Duplex (FDD) mode, the DL and UL channels employ different carrier frequencies. In Time Division Duplex (TDD) mode, the DL and UL channels share the same carrier frequency, but are allocated different time slots. In order to avoid interference between uplink transmission and downlink transmission, FDD is used on completely separate frequency bands. In TDD, uplink and downlink traffic are transmitted on the same frequency band but at different time intervals. Therefore, the uplink and downlink traffic are sent separately from each other, and in the time dimension of TDD transmission, there may be a Guard Period (GP) between the uplink and downlink transmission. In order to avoid interference between the uplink and the downlink, for the radio network nodes and/or UEs in the same area, uplink and downlink transmissions between the radio network nodes and UEs in different cells may be aligned to a common time reference in a synchronized manner, and the same resource allocation is used for the uplink and the downlink.

In general, the radio channels from TP to UE and from UE to TP may be characterized by different propagation conditions, which result in different degrees of Channel Quality (CQ). In FDD mode, each UE independently evaluates the CQ of its inbound DL channel and reports the Channel Quality Information (CQI) thus obtained to the TP over the UL channel. A similar mechanism is employed to evaluate and report CQs for the UL. This CQI estimation and reporting technique is also sometimes used in TDD mode.

Alternatively, in TDD mode, due to the reciprocal nature of the wireless channel, it can be assumed that the radio channels from TP to UE and from UE to TP have the same propagation conditions. Thus, the UE and TP may independently evaluate the CQ of the inbound channel and utilize this information to adapt to the channel conditions of the outbound channel.

The exchanged information between the UE and the TPs is organized in the form of a stream. Each flow carries a series of messages for the same UE. The messages are independently coded and modulated prior to transmission. Rate Matching (RM) blocks at the output of the channel encoder adapt the code blocks generated by the channel encoder to the number of time-frequency resource elements that can be transmitted. The scheme of fig. 1 shows the encoding and modulation process of an information message.

To provide a suitable level of error protection, the encoder, rate matching and modulator parameters are selected as a function of the CQ on the TP-UE link. The TP entity responsible for performing this selection is the scheduler. For a given UE-TP channel quality, the scheduler selects the most appropriate code type, rate and modulation order required to ensure that an adequate level of error protection is provided while providing the required data rate.

The Multiple Access (MA) scheme enables multiple users, wishing to independently transmit their information streams, to simultaneously access a shared channel. To avoid interference between users or other degradation that may result in reduced reliability or reduced performance, the MA needs to employ appropriate coordination techniques.

Traditional MA approaches, such as Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Space Division Multiple Access (SDMA), and Code Division Multiple Access (CDMA), rely on different types of channel resource allocations to avoid interference, e.g., by frequency, time, space, and coding.

The widely used Orthogonal Frequency Division Multiplexing (OFDM) modulation technique makes available a set of orthogonal (i.e. independent) time-frequency resource elements that can be allocated to different data streams, resulting in a so-called Orthogonal Frequency Division Multiple Access (OFDMA) scheme.

In mathematical terms, it can be said that the user data streams are made orthogonal in the vector space of the transmission signal by these technical means.

In a wireless communication system with high density of users, it is found that propagation conditions of a plurality of user groups within a service area are similar. In these cases, the CQI values fed back to the RAN by all users coincide in the group. Thus, the RAN can group users according to its own DL CQ. The messages transmitted to users in the same group are encoded using the same code type, rate and modulation parameter values.

As more and more UEs are used and the demand for single user (per-user) data rates is increasing, future wireless cellular systems will have to increase the aggregate data rate.

The MA scheme is adopted to make it possible for a plurality of users to simultaneously access a shared large-capacity channel. The main goal of the MA scheme is to achieve the highest possible aggregate data rate or spectral efficiency while providing the same level of error protection for all streams.

One problem with orthogonal multiplexing schemes (FDMA, TDMA, orthogonal CDMA) is that they are generally not optimal in terms of spectral efficiency. Very orthogonality is a design deficiency, usually caused by the low complexity of the receiver it exhibits.

An idea of layered modulation has been proposed and has been applied in image coding and video transmission. In particular, layered QAM modulation has been employed in the DVB-T standard for terrestrial broadcasting of digitally encoded video streams. The main purpose of these schemes is to transmit multiple data streams simultaneously in an open-loop broadcast system with unequal error protection. In the DVB-T standard, two streams, a high priority stream and a low priority stream, are multiplexed into one modulated signal. In particular, the high priority stream is characterized by high reliability bits in the constellation and the low priority stream is characterized by low reliability bits in the constellation.

The 3GPP2 standard defines in a similar way a transmission mode based on layered modulation, in which a base modulation layer and a so-called enhancement layer overlap to form a high-order constellation. Here, the purpose of the enhancement layer is to provide a service with enhanced quality to users with sufficiently good channel conditions, while providing a lower quality of service to users capable of decoding only the base layer.

The feature of layered modulation is exploited in order to employ opportunistic scheduling to schedule simultaneous transmissions of two best users in a transmission system. In order to decide how to divide the total available transmission rate for a selected number of users, a "Bit allocator" block is designed. The protection levels resulting from the bit allocation are in most cases unequal. Furthermore, the "bit allocator" block is time invariant, i.e. static.

The superposition modulation may be obtained by linearly combining a plurality of modulation signals. The binary labels of the resulting constellation are obtained by said linear combination and are not improved without changing the modulation scheme.

Thus, there is room for improvement when communicating in a multiple access environment.

Disclosure of Invention

It is therefore an object of the present invention to obviate at least some of the above disadvantages and to improve performance in a wireless communication system.

This and other objects are achieved by the features of the attached independent claims. Further embodiments are obtainable on the basis of the dependent claims, the description and the drawings of the description.

According to a first aspect, a method for a transmitter in a wireless communication network is provided. The method is directed to multiplexing data streams in a multiple access environment. The method comprises the following steps: data is transmitted on a plurality of data streams, the data to be received by at least one receiver. The method further comprises the following steps: a channel quality estimate is obtained. In addition, the method further comprises: selecting a plurality of data streams based on the obtained channel quality estimates. Further, the method comprises: determining a modulation scheme to be used for the selected data stream based on the obtained channel quality estimate. Furthermore, the method further comprises: a binary flag is formed that can contain the bits of all data streams and each bit in the flag is mapped with a selected data stream. The method further comprises the following steps: determining the value of the formed binary flag by collecting a plurality of bits from all data streams according to the mapping. Further, the method further comprises: selecting, in the determined modulation scheme, constellation points marked according to the determined binary labels. Furthermore, the method further comprises: and sending data representing the selected constellation point in a time-frequency resource element.

In a first possible implementation form of the method according to the first aspect, the mapping is performed dynamically such that the number of times each bit in the formed binary flag is mapped to each selected data stream is similar over a period of a plurality of symbol intervals including at least two symbol intervals. Thus, a similar level of error protection across all selected data streams may be achieved.

In a second possible implementation form of the method according to the first aspect as such or according to the first possible implementation form of the method according to the first aspect, the mapping is performed periodically to achieve a similar level of error protection on all selected data streams over a period comprising at least two symbol intervals. Thus, by cycling the mapping periodically, binary indicia can be constructed with any permutation order of the bitmap indices.

In a third possible implementation of the method according to the first aspect as such or any of the preceding possible implementations of the method according to the first aspect, the obtained channel quality estimate relates to a channel that is indirectly directed to the data stream; and selecting a data stream when a difference between the received channel quality estimates is less than a threshold.

In a fourth possible implementation of the method according to the first aspect as such or any of the preceding possible implementations of the method according to the first aspect, the first data stream and the second data stream are selected. Furthermore, the determined modulation scheme provides a plurality of different error protection levels for different bits of the binary flag, wherein each different error protection level comprises an even number of bits within the formed binary flag, wherein in each odd symbol interval, for each protection level: a first half of the bits are mapped with the first data stream and a second half of the bits are mapped with the second data stream, and in each even symbol interval, the first half of the bits are mapped with the second data stream and the second half of the bits are mapped with the first data stream.

In a fifth possible implementation of the method according to the first aspect or any of the preceding possible implementations of the method according to the first aspect, K data streams of the plurality of available data streams for which Z ≧ K are selected. In addition, by collecting m from each of the selected K data streams₀One bit forming the binary mark having a length m₀A binary flag of K bits. Further, the determined modulation scheme includes having

A high order extended constellation of symbols. Furthermore, the binary flag is formed in such a way that the K data streams have similar levels of error protection.

In a sixth possible implementation of the method according to the first aspect as such or any of the preceding possible implementations of the method according to the first aspect, the transmitter comprises a transmission point, TP, where the transmission of data is in downlink and is to be received by at least one receiver comprising a user equipment, UE.

In a seventh possible implementation of the method according to the first aspect as such or according to a sixth possible implementation of the method according to the first aspect, the transmitter comprises a user equipment, UE, wherein the transmission of data is in an uplink of the same transmission circuitry and is to be received by at least one receiver comprising a transmission point, TP.

In an eighth possible implementation of the method according to the first aspect as such or any of the preceding possible implementations of the method according to the first aspect, the transmitter is configured to operate in a TDD mode, and the act of obtaining a channel quality estimate comprises receiving a signal from the receiver on a reverse link and estimating a channel quality of the received signal.

In a ninth possible implementation of the method according to the first aspect as such or any of the preceding possible implementations of the method according to the first aspect, the transmitter is configured to operate in FDD mode or TDD mode, and the act of obtaining a channel quality estimate comprises receiving a channel quality estimate from the receiver.

In a second aspect, a transmitter for data transmission in a wireless communication network is provided, wherein the transmitter is configured to multiplex data streams in a multiple access environment. The transmitter includes: transmit circuitry to transmit data on a plurality of data streams, the data to be received by at least one receiver, and to transmit data characterizing constellation points in time-frequency resource elements. Further, the transmitter further includes: a receiving circuit for obtaining a channel quality estimate. In addition, the transmitter further includes: a processor configured to select a plurality of data streams based on the obtained channel quality estimates; and further configured to determine a modulation scheme to be used for the selected data stream based on the obtained channel quality estimate associated with the selected data stream. The processor is further configured to form a binary flag capable of containing bits of all data streams and map each bit in the flag with a selected data stream. Additionally, the processor is further configured to determine a value of the formed binary flag by collecting a plurality of bits from the data stream according to the mapping. The processor is further configured to select, in the determined modulation scheme, constellation points labeled according to the determined binary labels.

In a first possible implementation manner of the second aspect, the processor is further configured to dynamically perform the mapping such that the number of times each bit in the formed binary flag is mapped to each selected data stream is similar in a period including at least two symbol intervals.

In a second possible implementation of the second aspect or the first possible implementation of the second aspect, the processor may be further configured to perform the mapping periodically to achieve a similar level of error protection on the selected data streams over a period comprising at least two symbol intervals.

In a third possible implementation of the second aspect or any one of the preceding possible implementations of the second aspect, the obtained channel quality estimate relates to a channel that is indirectly directed to a data stream. The processor is further configured to select a data stream when a difference between the received channel quality estimates is less than a threshold.

In a fourth possible implementation of the second aspect or any of the preceding possible implementations of the second aspect, the processor is further configured to select a first data stream and a second data stream. The processor is further configured to determine a modulation scheme that provides a plurality of different error protection levels for different bits of the binary flag, wherein each different error protection level comprises an even number of bits within the binary flag, wherein in each odd symbol interval, for each protection level: a first half of the bits are mapped with the first data stream and a second half of the bits are mapped with the second data stream, and in each even symbol interval, the first half of the bits are mapped with the second data stream and the second half of the bits are mapped with the first data stream.

In a fifth possible implementation of the second aspect or any of the preceding possible implementations of the second aspect, the processor is further configured to select K data streams of the plurality of available data streams for which Z ≧ K. Further, the processor is configured to select K data streams by collecting m from each of the selected K data streams₀One bit forming the binary mark having a length m₀A binary flag of K bits. In addition, the processor is further configured to determine to include having

A modulation scheme of a high order extended constellation of individual symbols; and the processor is further configured to form the binary flag in a manner such that the K data streams have similar levels of error protection.

In a sixth possible implementation of the second aspect or any one of the preceding possible implementations of the second aspect, the transmitter comprises a transmission point, TP, where transmission of data is in downlink for data to be received by at least one receiver comprising a user equipment, UE.

In a seventh possible implementation of the second aspect or any of the preceding possible implementations of the second aspect, the transmitter comprises a user equipment, UE, wherein the transmission of data is in uplink and is to be received by at least one receiver comprising a TP.

In an eighth possible implementation of the second aspect or any of the preceding possible implementations of the second aspect, the transmitter is configured to operate in a TDD mode and to receive a signal from the receiver on a reverse link and to estimate a channel quality of the received signal.

In a ninth possible implementation of the second aspect or any one of the preceding possible implementations of the second aspect, the transmitter is configured to operate in FDD mode or TDD mode, and is further configured to obtain the channel quality estimate by receiving the channel quality estimate from the receiver.

In another implementation form of the first aspect and/or the second aspect, a computer program is provided, which comprises program code for performing the method according to the first aspect or any of the preceding possible implementation forms of the first aspect, for multiplexing data streams in a multiple access environment, when the computer program is loaded into a processor of a transmitter according to the second aspect.

In yet another implementation form of the first aspect and/or the second aspect, a computer program product is provided that includes a computer readable storage medium having program code stored thereon for multiplexing data streams in a multiple access environment in a wireless communication system. The program code includes instructions for performing a method comprising: data is transmitted on a plurality of data streams, the data to be received by at least one receiver. The method further comprises the steps of: a channel quality estimate is obtained. Furthermore, the method comprises the steps of: selecting a plurality of data streams based on the obtained channel quality estimates. In addition, the method further comprises the steps of: determining a modulation scheme to be used for the selected data stream based on the obtained channel quality estimate. Furthermore, the method comprises the steps of: a binary flag is formed that can contain the bits of all data streams and each bit in the flag is mapped with a selected data stream. Furthermore, the method comprises the steps of: determining the value of the formed binary flag by collecting a plurality of bits from all data streams according to the mapping. The method further comprises the steps of: selecting, in the determined modulation scheme, constellation points marked according to the determined binary labels. The method further comprises the steps of: and sending data representing the selected constellation point in a time-frequency resource element.

According to a third aspect, a method in a receiver in a wireless communication network for receiving at least one multiplexed data stream in a multiple access environment is provided. The method comprises the following steps: data transmitted by a transmitter is received on at least one data stream. Furthermore, the method further comprises: determining a modulation scheme to be used for the received data stream based on the estimated channel quality or transmission parameter signaling information received from the transmitter. The method further comprises the following steps: data characterizing the constellation points is received in time-frequency resource elements. Further, the method comprises: demapping the received data by determining which bits of a binary label corresponding to the constellation point are associated with the data stream.

In a first possible implementation form of the third aspect, the receiver operates in a TDD mode.

In a second possible implementation manner of the third aspect or any one of the preceding possible implementation manners of the third aspect, the receiver operates in an FDD mode or a TDD mode, wherein the method further includes: a channel quality associated with a channel associated with the received data stream is estimated. Further, the method comprises: transmitting the estimated channel quality to be received by the transmitter.

In a third possible implementation of the third aspect or any one of the preceding possible implementations of the third aspect, the receiver comprises a UE; the reception is performed in downlink by data transmitted by a transmitter including the TP.

In a fourth possible implementation of the third aspect or any one of the preceding possible implementations of the third aspect, the receiver includes a TP; the receiving is performed in an uplink by data transmitted by a transmitter including the UE.

According to a fourth aspect, a receiver in a wireless communication network is provided for receiving data transmitted by a transmitter on at least one data stream and further for receiving data characterizing constellation points in time-frequency resource elements. The receiver further comprises: a processor configured to determine a modulation scheme to be used for the received data stream and further configured to demap the received data by determining which bits of a binary flag corresponding to the constellation point are associated with the data stream.

In a first possible implementation form of the fourth aspect, the receiver is configured to operate in a TDD mode.

In a second possible implementation form of the fourth aspect or any one of the preceding possible implementation forms of the fourth aspect, the receiver is configured to operate in an FDD mode or a TDD mode. The processor is also configured to estimate a channel quality associated with a channel associated with the received data stream. Further, the receiver further comprises: a transmit circuit to transmit the estimated channel quality to be received by the transmitter.

In a third possible implementation of the fourth aspect or any of the preceding possible implementations of the fourth aspect, the receiver comprises a UE; the reception of data transmitted by a transmitter including a TP is performed in downlink.

In a fourth possible implementation of the fourth aspect or any of the preceding possible implementations of the fourth aspect, the receiver includes a TP; the reception of data transmitted by a transmitter including the UE is performed in the uplink.

In another possible implementation form of the third aspect and/or the fourth aspect, a computer program is provided, which comprises program code for performing the method according to the third aspect or any one of the possible implementation forms of the third aspect, for receiving at least one multiplexed data stream in a multiple access environment when the computer program is loaded into a processor of a receiver according to the fourth aspect or any one of the possible implementation forms of the fourth aspect.

In yet another possible implementation form of the third aspect and/or the fourth aspect, a computer program product is provided, which includes a computer readable storage medium having program code stored thereon to receive at least one multiplexed data stream in a multiple access environment in a wireless communication system. The program code comprises instructions for performing a method according to the third aspect or any one of its possible implementations, comprising: data transmitted by a transmitter is received on at least one data stream. The method further comprises the steps of: determining a modulation scheme to be used for the received data stream based on the estimated channel quality or transmission parameter signaling information received from the transmitter. Furthermore, the method comprises the steps of: data characterizing the constellation points is received in time-frequency resource elements. The method further comprises the steps of: demapping the received data by determining which bits of a binary label corresponding to the constellation point are associated with the data stream.

Due to the aspects described herein, it is possible to provide a heavy-duty multiple access scheme, where multiple independent data streams are combined to the same time-frequency resource element, the multiplexed data streams are transmitted simultaneously without requiring signal bandwidth, and the same or similar level of protection is provided for the transmitted data streams. Thereby, the data transmission rate within the wireless communication system can be increased without extending the signal bandwidth and without causing the data streams to exhibit unequal levels of protection. Accordingly, the performance of the wireless communication system is improved.

Other objects, advantages and novel features of various aspects of the invention will become apparent from the following detailed description.

Drawings

Various embodiments are described in more detail with reference to the accompanying drawings, in which:

fig. 1 shows message coding and modulation according to the prior art.

Fig. 2 is a block diagram illustrating a wireless communication system in accordance with some embodiments.

Fig. 3A is a block diagram illustrating a transmitter according to some embodiments.

Fig. 3B is a block diagram illustrating a receiver according to some embodiments.

Fig. 4A shows an example of a constellation with binary labels and stream-label mapping.

Fig. 4B illustrates information of a binary input channel as a function of signal-to-noise ratio in a particular constellation according to an example.

Fig. 4C shows an example of a constellation with binary labels and stream-label mapping.

Fig. 4D illustrates information of a binary input channel as a function of signal-to-noise ratio in a particular constellation according to an example.

Fig. 4E shows an example of a constellation with binary labels and stream-label mapping.

Fig. 4F illustrates information of a binary input channel as a function of signal-to-noise ratio in a particular constellation according to an example.

Fig. 4G illustrates information of a binary input channel as a function of signal-to-noise ratio in a particular constellation according to an example.

Fig. 5A shows a constellation with binary labels and the corresponding set of signals divided according to a particular bit.

Fig. 5B shows a constellation with binary labels and the corresponding set of signals divided according to a particular bit.

Fig. 5C shows a constellation with binary labels and the corresponding set of signals divided according to a particular bit.

Fig. 5D shows a constellation with binary labels and the corresponding set of signals divided according to a particular bit.

FIG. 6 illustrates a dynamic stream-to-tag mapping according to an embodiment.

Fig. 7 is a flow chart illustrating a method of a transmitter according to an embodiment.

Fig. 8 is a block diagram illustrating a transmitter according to an embodiment.

Fig. 9 is a flow chart illustrating a method of a receiver according to an embodiment.

Fig. 10 is a block diagram illustrating a receiver according to an embodiment.

Detailed Description

Embodiments of the invention described herein are defined as a transmitter, a method in a transmitter, a receiver and a method in a receiver, which can be implemented in the embodiments described below. These embodiments may, however, be illustrated and implemented in many different forms and are not limited to the embodiments set forth herein; rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete.

Other objects and features may also become apparent from the following detailed description taken in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the embodiments disclosed herein, for which reference should be made to the appended claims. Furthermore, unless otherwise indicated, the drawings are not necessarily to scale and they are merely intended to conceptually illustrate the structures and procedures described herein.

Fig. 2 is a schematic diagram of a wireless communication system 100 that includes a transmitter 110 in communication with a first receiver 120-1 for a first stream 130-1 and a second receiver 120-2 for a second stream 130-2.

For example, the wireless communication system 100 may be based at least in part on radio access technologies such as 3GPP LTE, LTE-advanced, evolved Universal terrestrial radio Access network (E-UTRAN), Universal Mobile Telecommunications System (UMTS), Global System for Mobile communications (formerly: Mobile expert Group) (GSM)/enhanced data rates for GSM evolution (GSM/EDGE), Wideband Code Division Multiple Access (WCDMA), Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single Carrier FDMA (SC-FDMA) networks, worldwide interoperability for microwave Access (WiMax) or Ultra Mobile Broadband (UMB), High Speed Packet Access (HSPA) evolved Universal terrestrial radio Access (E-UTRA), Universal Terrestrial Radio Access (UTRA), GSM EDGE Radio Access Network (GERAN), and 3GPP2CDMA technologies such as CDMA20001x RTT and High Rate Packet Data (HRPD), only a few options are listed here. Within the technical scope of the present disclosure, the expressions "wireless communication network", "wireless communication system" and/or "cellular communication system" may sometimes also be used interchangeably. Further, the wireless communication network 100 may include a cellular network or a non-cellular network according to various embodiments.

According to various embodiments, wireless communication system 100 may be used for communication in a Frequency Division Duplex (FDD) and/or Time Division Duplex (TDD) environment.

The purpose of the example shown in fig. 2 is to simply summarize the wireless communication system 100 and the involved methods and nodes, e.g., the transmitter 110, the receiver 120 and the involved functions described herein. The method and wireless communication system 100 are subsequently described in a 3GPP LTE/LTE-advanced environment as a non-limiting example, but embodiments of the disclosed method and wireless communication system 100 may be based on another access technology, for example, any of those already listed above. Therefore, although the embodiments of the present invention may be described based on and using the terminology of the 3GPP LTE system, the embodiments are not limited to 3GPP LTE, LTE-advanced, and the like.

According to some embodiments, the transmitter 110 may be used for downlink transmission and may be referred to as: for example, a Transmission Point (TP), a base station, a NodeB, an evolved Node B (eNB or eNodeB), a base transceiver station, an access point base station, a base station router, a Radio Base Station (RBS), a micro base station, a pico base station (pico base station), a femto base station (femto base station), a home eNodeB, a sensor, a beacon device, a relay Node, a relay, or any other network Node for communicating with the receiver 120 over a wireless interface.

According to different embodiments and different lexical expressions, the receiver 120 may be characterized accordingly as: for example, a User Equipment (UE), a wireless communication terminal, a mobile cellular phone, a Personal Digital Assistant (PDA), a wireless platform, a mobile station, a tablet, a portable communication device, a laptop, a computer, a wireless terminal as a relay device, a relay node, a mobile relay device, a user equipment (CPE), a Fixed Wireless Access (FWA) node, or any other type of device for wireless communication with the transmitter 110.

However, according to some embodiments, the situation is likely to be reversed, such that the transmitter 110 may be used for uplink transmission, and according to different embodiments and different lexical expressions, may be referred to as: for example, a User Equipment (UE), a wireless communication terminal, a mobile cellular phone, a Personal Digital Assistant (PDA), a wireless platform, a mobile station, a tablet, a portable communication device, a laptop, a wireless terminal as a relay device, a relay node, a mobile relay device, a user equipment (CPE), a Fixed Wireless Access (FWA) node, or any other type of device for wireless communication with the receiver 120.

Thus, according to some such embodiments, depending on the radio access technology and/or terminology used, the receiver 120 may be characterized accordingly as: for example, a Transmission Point (TP), a base station, a NodeB, an evolved Node Bs (eNB or eNodeB), a base transceiver station, an access point base station, a base station router, a Radio Base Station (RBS), a micro base station, a pico base station (pico base station), a femto base station (femto base station), a home eNodeB, a sensor, a beacon device, a relay Node, a relay, or any other network Node for communicating with the transmitter 110 over a wireless interface.

It should be noted that the exemplary network arrangement consisting of one transmitter 110 characterized by the transmission points shown in fig. 2 and two receivers 120-1, 120-2 characterized by the respective UEs is to be considered only as a non-limiting example of an embodiment. The wireless communication system 100 may include any other number and/or combination of transmitters 110 and/or receivers 120. Thus, multiple receivers 120 and another configuration of the transmitter 110 may be involved in some embodiments.

Thus, "a" or "a" receiver 120 and/or transmitter 110, respectively, refer herein to a plurality of receivers 120 and/or transmitters 110, respectively, that may be involved according to some embodiments.

The methods disclosed herein relate to non-orthogonal Multiple Access schemes, which may be referred to as Constellation-extended Multiple Access (CEMA), where a higher order modulation may be employed to combine Multiple independent data streams (coded or uncoded) on a set of time-frequency resources, thereby achieving a higher aggregate data rate.

It would be beneficial if a non-orthogonal scheme could be developed that could achieve higher aggregate spectral efficiency and control the increase in complexity. Layered modulation and superposition modulation may become promising transmission techniques, which form the starting point for developing improved methods.

Embodiments disclosed herein do not exhibit hierarchical behavior. Indeed, according to this method, streams may be grouped based on their CQI values and transmitted with the same level of protection in a given set of time-frequency resources. Thus, in some embodiments, no layering may be established between the streams.

Rather, some embodiments disclosed herein may employ dynamic stream-to-marker mapping, which may achieve equal or similar error protection for all streams while providing robustness features for channels and other hardware impairments.

However, some embodiments disclosed herein may employ higher order constellations in a native form. The binary labels of the constellation can be chosen arbitrarily to improve the performance of the system.

Accordingly, a multiplexing method in a multi-user downlink scenario with channel quality feedback is disclosed herein. In some embodiments, the method may include transmitting Z downlink data streams in parallel, where the method employs a single time-frequency resource element, and the method embodiments may include the steps of: k data streams are selected from a plurality of Z (Z ≧ K) available data streams based on the channel quality feedback information. Further, some method embodiments may include: collecting m from each of said K data streams₀One bit formed to have a length of m₀A complex binary flag of K bits. Furthermore, the method embodiment may further include: in the marks marked by said composite binary mark

Constellation points are selected in a high order extended constellation of individual symbols. Further, in some embodiments, the method may include: and transmitting the selected constellation point in a time-frequency resource element. According to some embodiments, the K data streams are selected such that the selected K data streams are associated with the same or similar channel quality streams, wherein the composite binary signature may be formed in a manner such that the K data streams have similar error protection.

The embodiments disclosed herein may be applied to the downlink of the wireless communication system 100. The disclosed CEMA scheme may include a heavy-duty multiple access scheme, in which multiple independent data streams are combined onto the same time-frequency resource element. The combining may be performed by using higher order modulation. The multiplexed multiple data streams are then transmitted simultaneously on the same time-frequency resource without requiring an extended signal bandwidth. According to some embodiments, overloading is an instance of having multiple data streams multiplexed onto the same time-frequency resource element, resulting in an increase in data rate without requiring signal bandwidth expansion.

According to some embodiments, when transmitting a single data stream 130, it may be assumed that the signal may belong to the constellation χ₀The constellation may include M₀A complex signal. The modulation order of which can be defined as m₀＝log2M₀And it may coincide with the number of bits associated with each modulation symbol. Chi shape₀Each symbol in (a) may be associated with a binary label

And (4) associating. Hereinafter, χ₀Called base constellation 1, m₀May be referred to as base order (base order).

With higher order modulation, the K streams can be combined and sent simultaneously using the same time-frequency resource, thus not requiring longer transmission time or signal bandwidth. In order to make the encoded information of all K streams consistent without increasing the number of time-frequency resources, in some embodiments, the order may be set to m-Km₀A larger constellation of (a). Thus, the size of the new constellation may become:

and it can be considered as the base constellation χ₀The result of expanding into a larger constellation χ (expanded constellation). The signal of x can be represented by a binary vector (b)₁，...，b_m) E {0, 1} m.

In fig. 3A, a basic scheme of a CEMA sender 110 according to an embodiment is shown. The flow selection block may select K packets with the same or similar CQI from all available sets of Z ≧ K packets input using the CQI information provided by the scheduler. Thereafter, each of the K messages may be independently encoded and rate matching applied. The dynamic stream-to-mark mapping block computes the symbol marks of the constellation points as a function of the coded bits. Finally, in the constellation point selection block, a corresponding symbol may be selected from the extended constellation χ with a symbol mark, and a corresponding modulation signal may be generated.

The constellation symbol selection block shown in fig. 3A may generate a series of complex modulation symbols selected from the extended constellation χ according to the symbol labels. The disclosed CEMA scheme does not constitute any limitation.

Binary labeling of constellation points is typically performed according to the Gray rule (Gray rule), resulting in the following properties: the binary label pair associated with the constellation point with the smallest Euclidean distance (Euclidean distance) differs by only one bit.

In fig. 3B, a scheme of an embodiment of a k-th CEMA receiver 120 is shown. The detector block may compute coded bit (soft or hard) estimates and feed them back to the marker-stream demapping block. The demapping block may calculate the coded bit estimates for the kth receiver 120 and may feed them back to the reverse rate matching and channel decoder block, which may ultimately calculate the information bit estimates.

Fig. 4A shows an example of a 16PSK (phase shift keying) constellation scheme 400 and stream-label mapping, the constellation scheme 400 having constellation points 410 associated with respective binary labels 420. In this non-limiting example, the binary flag 420 includes four bits b1, b2, b3, b 4. In other embodiments, any number n of bits may be included in binary flag 420, where 0 < n < ∞. Furthermore, any number K of streams 130-1,130-2 may be involved in some embodiments, where 0 < K ∞.

The illustrated constellation 400 is one example of a static stream-to-tag mapping: the rightmost two bits of the binary flag 420 are allocated to stream 1130-1 (normal) and the leftmost two bits of the binary flag are allocated to stream 2130-2 (raised).

Fig. 4B shows information of a binary input channel obtained by 16PSK decomposition.

A common feature of most modulation schemes (e.g., in 16PSK as shown in fig. 4A) is that different bits b1, b2, b3, b4 convey different amounts of information, thus resulting in different levels of error protection. This effect will be described in further detail in conjunction with fig. 5A-5D.

There are three different levels of protection in the 16PSK modulation scheme 400. This feature is illustrated in fig. 4B, where the amount of information carried by each of the four binary input channels obtained by 16PSK decomposition is a graph against the signal-to-noise ratio (SNR or S/N). This number is referred to herein as the protection level of each bit b1, b2, b3, b4 in binary flag 420.

The signal-to-noise ratio measurement employed herein may be replaced by any similar ratio related to the ratio between the desired signal level and the background noise level, such as signal-to-interference and noise ratio (SINR), signal-to-noise and interference ratio (SNIR), signal-to-interference ratio (SIR), signal-to-noise ratio (SINAD), signal-to-quantization and noise ratio (SQNR), carrier-to-noise ratio (C/N), signal-to-noise ratio (NSR), or any similar measurement.

Fig. 4C shows a binary labeled 16-APSK constellation 400 specified in the DVB-S2 standard.

For example, an Amplitude Phase Shift Keying (APSK) type constellation 400 is employed in the DVB-S2 standard. In these constellations 400, complex symbols (dots) are arranged on a plurality of concentric rings. Where a ring has M equally spaced symbols, this results in M-PSK modulation, such as 16PSK or 32PSK, to name a few.

As shown in fig. 4D, there are two different levels of protection in the 16APSK constellation 400.

The shape of the APSK modulation scheme 400 shown in fig. 4A and 4C, respectively, may result in a low peak-to-average power ratio (PAPR), which is a good feature for a power-limited wireless communication system 100. This feature is expected to be very significant for future wireless systems 100 deployed with a large number of low power access points.

Fig. 4E shows an embodiment of a 16QAM (quadrature amplitude modulation) constellation 400 with gray labels and an example of stream-label mapping.

The square M-QAM constellation 400 may be particularly significant since it is widely used. The size of the square M-QAM constellation 400 may be M-2^mWhere m is any even positive integer. In general, M-QAM modulation scheme 400 is a complex set of points defined as χ { ± si ± js_Q}. Here, the first and second liquid crystal display panels are,

s_I，s_Qis any odd positive integer less than or equal to M. Fig. 4E shows a 16-QAM constellation 400 with gray marks and a possible stream-to-mark mapping scheme. The rightmost two bits b1, b2 of the binary flag 420 are allocated to the stream 1130-1 (normal), and the leftmost two bits b3, b4 of the binary flag 420 are allocated to the stream 2130-2 (raised).

The order is m ═ log₂There are M/2 different levels of protection in the square M-QAM constellation 400 for M. Fig. 4F shows this feature for 16-QAM and fig. 4G shows this feature for 256-QAM, where the amount of information carried by each of the m binary input channels obtained by QAM decomposition is a plot against SNR. For a fixed SNR value, there are m/2 unequal protection levels.

Fig. 5A-5D show how the 4 bits of the label 420 are characterized in the constellation 400 shown in fig. 4E. In this non-limiting example, constellation 400 comprises a 16QAM constellation. Intuitively, information transmitted through a binary channel corresponding to a bit position of i-1, 2 is different from information transmitted through a bit position of i-3, 4. The performance of the receiver will vary depending on which bit b1, b2, b3, b4 is evaluated, the euclidean distance being different.

For a constellation point 410 with a value 1011 in the binary flag 420, the two left-hand bits b3, b4 have the same value, 1 and 0 respectively, provided that the transmission is distorted and thus the receiver 120 erroneously interprets the constellation point 410 as characterizing a value 1000. However, the two rightmost bits, originally having values of 1 and 1, respectively, are erroneously interpreted as 0 and 0.

Thus, some constellation points 410 are grouped such that minor interference during transmission that causes a constellation point 410 to be misinterpreted as another adjacent constellation point 410 does not affect the understanding of the bits at some locations in the marker 420. However, some bits, such as b2 ═ 1 in fig. 5C and b1 ═ 1 in fig. 5D, are not grouped together in the constellation 400, which is why small interference may cause these bits to be misunderstood at the receiver side.

Fig. 6 illustrates a dynamic stream-to-tag mapping block. To combine all streams 130 and all parameters m₀And K, an equal or approximately equal level of protection, a suitable labeling method can be devised.

The dynamic stream-to-mark mapping block shown in fig. 6 maps m of each stream 130 to Q symbols of a predetermined period according to a mapping that changes from symbol to symbol₀One coded bit is associated with m bits of the symbol mark 420.

The dynamic stream-to-tag mapping may be via a permutation set Π of size m_qQ1., Q (where Q > 1) is specified. In each symbol interval, a different permutation is employed. After Q symbol intervals, the first permutation may be used again, and the order may be repeated.

The following explanation can be used for [1, m ]]The vector of unique integers in (ii) to define the permutation Π_q：i→Π_q，i: the ith input element to the permutation block is moved to position Π at its output_q，i. Then, the entire set of Q permutations may be specified using the m × Q mapping matrix, where the qth column corresponds to permutation Π_q。

To avoid ambiguity, it can be specified that the bits input to the stream-to-tag mapping are fed into the following permutation blocks, see fig. 6: beta is a_μ＝b_i，jWherein, index

And the index j ═ 1+ (μ -1) mod m₀. Here, (. beta.) (beta.)₁，...，β_m) Representing the input vector of the permuted block. Amount of the compound (A).

TABLE 1

Table 1 reveals the stream-to-tag mapping of a 16PSK constellation 400 with two streams 130-1,130-2 as shown in fig. 4A. Thus, the disclosed non-limiting example may correspond to the constellation 400 shown in fig. 4A. The stream-to-tag mapping does not change from symbol to symbol in this case, i.e., it is not dynamic, and thus has a period Q-1. An example of the resulting mapping matrix is shown in table 1. This example describes a stream-to-tag mapping that is not part of the method, as it is not dynamic. In addition, it does not provide similar error protection for all streams 130-1, 130-2. Instead, it illustrates the problems associated with static mapping according to the prior art.

As can be seen in fig. 4B, the 16PSK constellation exhibits three different levels of protection (strong, medium, weak) for a fixed SNR. Two high level protected (strong) bits b3, b4 are allocated to stream 2130-2, while two weaker level protected bits b1, b2 are allocated to stream 1130-1. This static stream-marker assignment is clearly unequal in terms of error protection. It can also be observed that it is not possible to obtain equal stream protection by means of static mapping. Instead, it can be seen that a simple dynamic mapping with a period Q-2 achieves equal protection for both streams 130-1, 130-2. As shown in table 2.

TABLE 2

Table 2 reveals an equal guard stream-to-mark mapping of a 16PSK constellation 400 with two streams 130-1, 130-2.

For the 16APSK modulation scheme 400 as shown in fig. 4C, the protection level is shown in fig. 4D, which is quite different: only two unequal protection levels are present and it is therefore possible to perform equal protection mapping, on both information streams 130-1,130-2 in cycle 1.

Similar considerations apply for the two-stream case for square M-QAM modulation. Fig. 4E shows a 16QAM constellation. As can be seen in fig. 4F, constellation 400 exhibits two different levels of protection.

TABLE 3

Table 3 reveals the stream-to-mark mapping for a 16QAM constellation with two streams 130-1,130-2 as shown in fig. 4E.

This mapping obviously results in unequal protection because all strong bits are allocated to stream 2130-2, while stream 1130-1 gets all weak bits. However, another equal protection mapping may be designed as shown in table 4A and/or table 4B. Each stream 130-1,130-2 may use one strong bit (bit 3 or bit 4) and one weak bit (bit 1 or bit 2) in the illustrated embodiment.

TABLE 4A

Table 4A reveals an equal protection mapping for a 16-QAM constellation with two streams 130-1,130-2 according to an embodiment. This is a non-dynamic embodiment and is not part of the method described herein.

Thus, in some cases, it is possible to design a static map with equal protection. However, when additional channel impairments are taken into account, for example: since the I/Q independent interleaving can act independently on the fading of the I and Q components, and other propagation phenomena such as beam depolarization and hardware impairments (non-linearity in the analog part and a/D conversion stages, I-Q imbalance, signal offset, etc.), the information characteristics of the modulation scheme under consideration will differ from the ideal characteristics shown in fig. 4B, 4D, 4F and 4G. As a result, such static mapping is likely to become unequal.

For these reasons, replacing the prior art non-dynamic stream-to-label mapping with the general dynamic mapping rules in our method can guarantee protection from the number of streams 130-1,130-2 and constellation 400, providing equal protection, while further increasing robustness against the above impairments.

Table 4B reveals a dynamic equal protection mapping of a 16-QAM constellation with two streams 130-1,130-2 according to an embodiment.

TABLE 4B

The stream-to-marker mappings shown in tables 1, 3, and 4A are not dynamic because they do not change from symbol to symbol. In other words, the period Q is 1. In general, mapping K streams to an extended constellation with P guard levels requires the use of dynamic labels, i.e., labels that change from symbol to symbol with a period of Q > 1. Thus, the static stream-to-tag mappings shown in tables 1, 3, and 4A are only used to illustrate the shortcomings of the prior art mappings.

In contrast, according to embodiments herein, a generic dynamic mapping is disclosed that achieves equal levels of protection on all streams 130-1,130-2 for all values of K and m. According to one embodiment, the period Q of the map is K and is represented in table 5. Here, each bit b1, b 2.., bn of the extended constellation is periodically allocated to K streams. Thus, each stream enjoys a level of error protection provided by each bit in the ratio of 1/K over the total transmission time: the message transmission is averaged and all flows are equally protected.

TABLE 5

Table 5 shows a generic equal protection map.

In some embodiments it may be found that the period Q of the equal protection mapping scheme is less than K. The 16-QAM mapping shown in table 4B is an example and can be summarized as follows: consider the case where two information streams are multiplexed on an M-QAM type spreading constellation. In this case, it can be observed that for a given SNR, bits 2i-1 and 2i (i ═ 1.. m/2) exhibit the same level of error protection, see the example of 256-QAM in fig. 4G. Thus, assigning odd-positioned bits to one stream 130-1 and even-positioned bits to the other stream 130-2 implements equal protection mapping. This mapping is shown in table 6, where the mapping is extended to Q2 symbols for the reasons described above, resulting in a dynamic stream-to-tag mapping.

TABLE 6

After permutation, by fitting the binary vector (u)₁，...，u_m) Converting to integer values to compute the symbol tokens as follows:

furthermore, some embodiments disclosed herein may be applicable to all bit interleaved coded modulation transmission systems, possibly combining OFDM and MIMO transmission.

Fig. 7 is a flow chart illustrating an embodiment of a method 700 of the transmitter 110 in the wireless communication system 100. The method 700 is directed to providing multiplexed data streams 130-1,130-2 in a multiple access environment by providing dynamic stream-to-marker mapping.

In some embodiments, transmitter 110 may include a Transmission Point (TP); data transmitted in the downlink is received by at least one receiver 120 including a User Equipment (UE). However, in some embodiments, the transmitter 110 may comprise a UE, may transmit data in the uplink of the same transmission circuitry, and may receive the transmitted data by at least one receiver 120, including a TP.

In some embodiments, the wireless communication network 100 may be based on the third generation partnership project long term evolution (3gpp lte). In some such embodiments, the transmitter 110 may include an evolved base station (eNodeB). Further, the wireless communication system 100 may be based on FDD or TDD in different embodiments.

In order to properly provide the multiplexed data streams 130-1,130-2, the method 700 may include a plurality of acts 701-708.

It should be noted, however, that any, some or all of the acts 701-708 may be performed in a different temporal order than the illustrated example, and that the acts 701-708 may be performed simultaneously or even in an entirely reverse order, depending on the embodiment. Further, it should be noted that some acts may, in accordance with different embodiments, be performed in a number of alternative ways, which may be performed in only some embodiments, but not necessarily all embodiments. The method 700 may include the following acts:

action 701

Data to be received by at least one receiver 120 is transmitted over multiple data streams 130-1, 130-2. The plurality of data streams 130-1,130-2 may include, for example, Z data streams 130-1,130-2, where 0 < Z < ∞. One or more data streams 130-1,130-2 may be associated with one or more receivers 120.

Act 702

A channel quality estimate is obtained.

In some embodiments, where transmitter 110 operates in a Time Division Duplex (TDD) mode, the channel quality may be estimated by receiving a signal from receiver 120 on the reverse link and estimating the channel quality of the received signal.

In some other embodiments, where the transmitter 110 operates in Frequency Division Duplex (FDD) mode or Time Division Duplex (TDD) mode, the channel quality estimate may include receiving the channel quality estimate from the receiver 120.

The channel quality estimate or Channel Quality Information (CQI) may be related to a channel involving the transmitter 110 and the receiver 120, and may be directed indirectly to the data streams 130-1,130-2 in some embodiments.

Act 703

K data streams 130-1,130-2 are selected based on the channel quality estimates obtained at 702, where K is greater than or equal to 0 and less than or equal to Z.

In some embodiments, the K data streams 130-1,130-2 may be selected when the difference between the channel quality estimates (e.g., CQI) obtained at 702 is less than a threshold. The threshold may be predetermined or configurable.

Act 704

Based on the channel quality estimates obtained at 702, the modulation scheme 400 to be used for the selected data stream 130-1,130-2 may be determined 703.

In different embodiments, the modulation scheme 400 may comprise, for example, an APSK constellation or a QAM constellation.

Act 705

Forming a binary marker 420 capable of containing bits b1, b2,..... ann, bn of all K data streams 130-1,130-2 and mapping each bit in the marker 420 with the selected 703 data stream 130-1, 130-2;

the mapping is performed dynamically such that the number of times each bit b1, b2,... said, bn is mapped to each of the 703 selected K data streams 130-1,130-2 is similar or equal over a period comprising at least two symbol intervals. In some embodiments, the number of symbol intervals n equals the number K of 703 selected data streams 130-1,130-2, the number of times bn is mapped to each of 703 selected K data streams 130-1,130-2 is similar or equal, for each bit b1, b 2.

The mapping may be performed periodically to achieve similar levels of error protection across all streams 130-1,130-2 selected 703, over a period comprising at least two symbol intervals, e.g., in some embodiments, over a period in which the number n of symbol intervals equals the number K of 703 selected data streams 130-1,130-2, e.g., in some embodiments, the number n of symbol intervals equals the number K of selected 703 data streams 130-1, 130-2.

Act 706

The value of the formed binary flag 420 is determined 705 by collecting n bits b1, b 2.. once.bn from all K data streams 130-1,130-2 according to the performed mapping. Thus, the number n of bits b1, b 2.. the number bn may be equal to the number K of 703 selected data streams 130-1,130-2, i.e., n ═ m0K.

Act 707

In the modulation scheme 400 determined 704, constellation points 410 marked according to the binary markers 420 determined 706 are selected.

Act 708

Data characterizing 707 the selected constellation point 410 is transmitted in a time-frequency resource element.

According to some embodiments, 703 may select the first data stream 130-1 and the second data stream 130-2. The modulation scheme 400 determined 704 may exhibit a plurality of unequal error protection levels for different bits b1, b 2.. said, bn of the binary marker 420, wherein each unequal error protection level may comprise an even number of bits b1, b 2.. said, bn within the binary marker 420 formed 705. Further, in each odd symbol interval, for each guard level: a first half-number of bits b1, a. -, b (n-1) may be mapped with the first data stream 130-1, a second half-number of bits b2, a. -., bn may be mapped with the second data stream 130-2, and in each even symbol interval, the first half-number of bits b1, a. -, b (n-1) may be mapped with the second data stream 130-2, and the second half-number of bits b2, a. -, bn may be mapped with the first data stream 130-1.

However, in some embodiments 703 may select K data streams 130-1,130-2 of the plurality of available data streams 130-1,130-2 for which Z ≧ K. M may be collected by each of the K data streams 130-1,130-2 selected from 703₀Bits b1, b2₀) To form 705 said binary flag 420. Thus, a length of m can be formed₀A binary flag 420 of K bits b1, b 2.., b (m 0K). 704 may include determining a modulation scheme 400 having

A high order extended constellation of symbols. Further, in some embodiments, the binary flag 420 formed by 705 may be formed in a manner such that the K data streams 130-1,130-2 have similar or equal levels of error protection.

Fig. 8 shows an embodiment of a transmitter 110 comprised in the wireless communication system 100. The sender 110 is configured to perform at least part of the aforementioned method actions 701-708 for multiplexing the data streams 130-1,130-2 in a multiple access environment by providing a dynamic stream-marker mapping.

The wireless communication network 100 may be based on the third generation partnership project long term evolution (3GPP LTE). In some embodiments, the transmitter 110 may include, for example: a Transmission Point (TP) or a radio network node such as an evolved base station (eNodeB). Further, the wireless communication system 100 may be based on FDD or TDD in different embodiments. In some embodiments, receiver 120 may comprise a User Equipment (UE), wherein data transmission is in the downlink.

However, in some embodiments, the situation may be reversed, i.e. the transmitter 110 comprises a UE, wherein the transmission of data takes place in the uplink and is received by at least one receiver 120, which may comprise a TP or a radio network node such as an eNodeB.

Accordingly, the sender 110 is configured to perform the method 700 based at least in part on the actions 701 and 708. For greater clarity, any internal electronics or other components of the transmitter 110 that are not essential to an understanding of the embodiments described herein have been omitted from fig. 8.

The transmitter 110 comprises a transmitting circuit 830 for transmitting data to be received by at least one receiver 120 over a plurality of data streams 130-1,130-2 and for further transmitting data characterizing the constellation points 410 in time-frequency resource elements.

In some embodiments, the transmitter 110 may include a receiving circuit 810, the receiving circuit 810 configured to obtain a channel quality estimate, e.g., a CQI, from at least one receiver 120.

According to some embodiments, the receiving circuitry 810 in the transmitter 110 may be used to receive any wireless signal from the receiver 120 or any other arbitrary entity that communicates wirelessly over a wireless interface.

The channel quality estimate received from the at least one receiver 120 may be channel dependent and thus, in some embodiments, directed indirectly to the data streams 130-1, 130-2.

Further, the transmitter 110 further includes: a processor 820 configured to select K data streams 130-1,130-2 based on the obtained channel quality estimates. For example, data streams 130-1,130-2 associated with received channel quality estimates that exceed a first threshold but do not exceed a second threshold, where the second threshold is higher than the first threshold, may be selected. Further, the processor 820 is configured to determine the modulation scheme 400 to be used for the selected data stream 130-1,130-2 based on the received channel quality estimates associated with the selected K data streams 130-1, 130-2. The processor 820 is further configured to form a binary marker 420 that can contain n bits b1, b2, b3, a.... times, bn of all K data streams 130-1,130-2, and map each bit in the marker 420 with a selected data stream 130-1, 130-2. In addition, the processor 820 is further configured to determine a value of the formed binary flag 420 by collecting n bits b1, b2, a. The processor 820 is further configured to select, in the determined modulation scheme 400, the constellation point 410 labeled according to the determined binary label 420.

The processor 820 may be further configured to dynamically perform the mapping such that the number of times bn is mapped to each selected data stream 130-1,130-2 is similar for each bit b1, b 2. In some embodiments, the number of symbol intervals may be equal to the number K of selected data streams 130-1, 130-2.

In some embodiments, the processor 820 may be further configured to perform the mapping periodically to achieve a similar level of error protection on the selected K data streams 130-1,130-2 over a period comprising at least two symbol intervals. In some embodiments, the number of symbol intervals, n, may be equal to the number, K, of selected data streams 130-1,130-2, such that n-K. In some such embodiments, the input indices of the bits b1, b 2.

The processor 820 may be further configured to select the data streams 130-1,130-2, for example, when a difference between the received channel quality estimates is less than a threshold. The threshold may be predetermined or configurable in different embodiments.

The processor 820 may be further configured to select the first data stream 130-1 and the second data stream 130-2. Further, the processor 820 may be configured to determine a modulation scheme 400, the modulation scheme 400 providing a plurality of different error protection levels for different bits b1, b 2...... times, bn of the binary flag 420, wherein each different error protection level comprises an even number of bits b1, b 2.. times, bn within the binary flag 420, wherein in each odd symbol interval, for each protection level: a first half-number of bits b1, a. -, b (n-1) may be mapped with the first data stream 130-1, a second half-number of bits b2, a. -., bn may be mapped with the second data stream 130-2, and in each even symbol interval, the first half-number of bits b1, a. -, b (n-1) may be mapped with the second data stream 130-2, and the second half-number of bits b2, a. -, bn may be mapped with the first data stream 130-1.

The processor 820 may include one or more examples of processing circuitry, such as a Central Processing Unit (CPU), processing unit, processing circuit, processor, Application Specific Integrated Circuit (ASIC), microprocessor, or other processing logic that may interpret and execute instructions. Thus, the expression "processor" as used herein may refer to a processing circuit including, for example, any, some or all of the various processing circuits listed above.

The processor 820 may also be used in some embodiments to select K data streams 130-1,130-2 from among Z ≧ K number of available data streams 130-1, 130-2. Further, the processor 820 may be further configured to select K data streams 130-1 and 130-2 by collecting n-m₀K bits b1, b2, b3₀K bits b1, b 2., a binary flag 420 for bn. Further, the processor 820 may be configured to determine whether to include having

A modulation scheme 400 of a high order spread constellation of symbols. The processor 820 may also be configured to form the binary flag 420 in a manner such that the K data streams 130-1,130-2 have similar or equal levels of error protection.

Further, according to some embodiments, the transmitter 110 may also include at least one memory 825 in the transmitter 110 in some embodiments. Optional memory 825 may comprise a physical device for temporarily or permanently storing data or programs, such as sequences of instructions. According to some embodiments, the memory 825 may comprise an integrated circuit comprising silicon-based transistors. Further, the memory 825 may be volatile or nonvolatile.

The actions 701-708 to be performed in the sender 110 may be implemented by one or more processors 820 in the sender 110 together with a computer program comprising program code for performing the method 700 according to the actions 701-708 described above for multiplexing data streams 130-1,130-2 in a multiple access environment when the computer program is loaded into the processor 820 of the sender 110.

According to some embodiments, the actions 701-708 to be performed in the transmitter 110 may also be implemented by one or more processors 820 in the transmitter 110 in conjunction with a computer program product comprising a computer readable storage medium having program code stored thereon for multiplexing data streams 130-1,130-2 in a multiple access environment in a wireless communication system 100, the program code comprising instructions for performing the method 700 comprising: 701, transmitting data to be received by at least one receiver 120 on a plurality of data streams 130-1, 130-2; 702, obtaining a channel quality estimate; 703 selecting K data streams 130-1,130-2 based on said obtained 702 channel quality estimate; 704, determining a modulation scheme 400 to be used for said selected 703K data streams 130-1,130-2 based on said obtained 702 channel quality estimate; 705 forming a binary marker 420 capable of containing bits b1, b2,...... ann, bn of all K data streams 130-1,130-2 and mapping each bit in the marker 420 with 703 selected data streams 130-1, 130-2; according to the mapping by collecting n bits b1, b2 from each of the K data streams 130-1, 130-2; 706, determining 705 the value of the formed binary flag 420; 707, in the modulation scheme 400 determined 704, selecting constellation points 410 marked according to the binary markers 420 determined 706; and 708, transmitting data characterizing 707 the selected constellation point 410 in the time-frequency resource elements.

The above mentioned computer program product may be provided in the form of a data carrier carrying computer program code for performing a part of the actions 701 and 708 according to some embodiments when the computer program code is loaded into the processor 820. The data carrier may be, for example, a hard disk, a read-only optical disk, a memory stick, an optical storage device, a magnetic storage device, or any other suitable medium, such as a magnetic disk or tape, that may hold machine-readable data in a non-transitory manner. The computer program product may further be provided as computer program code on a server and downloaded to the sender 110, e.g. over an internet or an intranet connection.

Fig. 9 is a flow chart illustrating an embodiment of a method 900 for the receiver 120 in the wireless communication system 100. The method 900 is directed to receiving at least one multiplexed data stream 130-1,130-2 in a multiple access environment by providing feedback in the form of channel quality estimates to the transmitter 110.

The wireless communication network 100 may be based on 3GPP LTE in some embodiments. In some embodiments the receiver 120 may comprise a UE, wherein the receiver 120 receives data transmitted by the transmitter 110, which may comprise a TP or a radio network node such as an eNodeB, in the downlink. Further, the wireless communication system 100 may be based on FDD or TDD in different embodiments.

However, in some embodiments, the situation may be reversed, i.e. the receiver 120 may comprise a TP or a radio network node such as an eNodeB, where data transmission is performed in the uplink by the transmitter 110, which may comprise a UE.

In order to properly receive at least one multiplexed data stream 130-1,130-2, the method 900 may include acts 901 and 906.

It should be noted that any, some or all of the acts 901 and 906 may be performed in a different temporal order than the illustrated example, and that the acts 901 and 906 may be performed simultaneously or even in an entirely reverse order, depending on the embodiment. Further, it should be noted that some acts may, in accordance with different embodiments, be performed in a number of alternative ways, which may be performed in only some embodiments, but not necessarily all embodiments. The method 900 may include the following acts:

act 901

Data transmitted by the transmitter 110 is received 901 on at least one data stream 130-1, 130-2.

Act 902

This action may be performed in some embodiments, but not in all embodiments.

A channel quality associated with a channel associated with the received 901 data streams 130-1,130-2 may be estimated. In some embodiments, the channel estimate may include a CQI for a channel associated with the received 901 data stream 130-1, 130-2.

Act 903

This action may be performed in some embodiments, but not in all embodiments.

The estimated 902 channel quality is transmitted for reception by the transmitter 110. The channel quality may be associated with the received 901 data streams 130-1,130-2 and/or the receiver 120 to enable the transmitter 110 to detect to which data stream 130-1,130-2 the received channel quality estimate belongs.

Act 904

The modulation scheme 400 to be used for the received data stream 130-1,130-2 is determined 901 based on the estimated channel quality or transmission parameter signalling information received from said transmitter 110.

Act 905

Data characterizing the constellation point 410 is received 905 in the time-frequency resource elements. The data may be received in the form of time-frequency resource elements.

Act 906

The received data is demapped 905 by determining which bits b1, b2, b n are associated with 901 the received data streams 130-1,130-2 corresponding to the binary markers 420 of the constellation points 410.

Fig. 10 illustrates an embodiment of a receiver 120 included in the wireless communication system 100. The receiver 120 is configured to perform at least part of the aforementioned method actions 901-906 for receiving at least one multiplexed data stream 130-1,130-2 in a multiple access environment in some embodiments by providing feedback in the form of channel quality estimates to the transmitter 110.

The wireless communication network 100 may be based on 3GPP LTE in some embodiments. In some embodiments the receiver 120 may comprise a UE, wherein the receiver 120 receives data transmitted by the transmitter 110, which may comprise a TP or a radio network node such as an eNodeB, in the downlink. Further, the wireless communication system 100 may be based on FDD or TDD in different embodiments.

However, in some embodiments, the situation may be reversed, i.e. the receiver 120 may comprise a TP or a radio network node such as an eNodeB, where data transmission is performed in the uplink by the transmitter 110, which may comprise a UE.

Accordingly, the receiver 120 is configured to perform the method 900 according to at least part of the actions 901 and 906. For greater clarity, any internal electronics or other components of receiver 120 that are not essential to an understanding of the embodiments described herein have been omitted from fig. 10.

The receiver 120 includes: a receiving circuit 1010 configured to receive data transmitted by the transmitter 110 on at least one data stream 130-1,130-2, and further configured to receive data characterizing the constellation point 410 in time-frequency resource elements.

The receiver 120 further includes: a processor 1020 for determining a modulation scheme 400 to be used for the received data streams 130-1, 130-2. The processor 1020 is also configured to demap the received data by determining which bits b1, b2,. a.. b, n of the binary marker 420 corresponding to a constellation point are associated with the data stream 130-1, 130-2.

In some embodiments, the processor is configured to estimate a channel quality associated with a channel associated with the received data stream 130-1, 130-2.

Processor 1020 may include one or more examples of processing circuitry, such as a Central Processing Unit (CPU), processing unit, processing circuit, processor, Application Specific Integrated Circuit (ASIC), microprocessor, or other processing logic that may interpret and execute instructions. Thus, the expression "processor" as used herein may refer to a processing circuit including, for example, any, some or all of the various processing circuits listed above.

Further, the receiver 120 comprises a transmitting circuit 1030 for transmitting said estimated channel quality to be received by said transmitter 110.

In some optional embodiments, the receiver 120 and/or the processor 1020 may include: an estimation unit for estimating a channel quality related to a channel associated with the received data stream 130-1, 130-2. Further, the receiver 120 and/or the processor 1020 may further include: a determining unit for determining a modulation scheme 400 to be used for the received data stream 130-1,130-2 based on the estimated channel quality or transmission parameter signalling information received from the transmitter 110. Further, the receiver 120 and/or the processor 1020 may further include: a demapping unit for demapping the received data by determining which bits b1, b2,.. b, bn are associated with the data streams 130-1,130-2 in the binary marker 420 corresponding to the constellation point 410.

Further, in some embodiments, the receiver 120 may also include at least one memory 1025 in the receiver 120. Optional memory 1025 may include a physical device for temporarily or permanently storing data or programs such as sequences of instructions. According to some embodiments, memory 1025 may comprise an integrated circuit that includes silicon-based transistors. Further, memory 1025 may be volatile or non-volatile.

The actions 901 and 906 to be performed in the receiver 120 may be implemented by one or more processors 1020 in the receiver 120 together with a computer program product for performing the functions of the actions 901 and 906.

The computer program therefore comprises program code for performing the method 900 according to any of the actions 901 and 906 for receiving at least one multiplexed data stream 130-1,130-2 in a multiple access environment when the computer program is loaded into the processor 1020 of the receiver 120.

According to some embodiments, a computer program product may include a computer readable storage medium having program code stored thereon for receiving at least one multiplexed data stream 130-1,130-2 in a multiple access environment in a wireless communication system 100, the program code including instructions for performing a method 900 comprising: determining 904 a modulation scheme 400 to be used for the received data stream 130-1,130-2 based on the estimated channel quality or the transmission parameter signaling information received from the transmitter 110; receiving 905 data characterizing a constellation point 410 in a time-frequency resource element; the received 905 data is demapped 906 by determining which bits b1, b2, a.

The above mentioned computer program product may be provided in the form of a data carrier carrying computer program code for performing at least part of said actions 901 and 906 when the computer program code is loaded into the processor 1020 according to some embodiments. The data carrier may be, for example, a hard disk, a read-only optical disk, a memory stick, an optical storage device, a magnetic storage device, or any other suitable medium, such as a magnetic disk or tape, that may hold machine-readable data in a non-transitory manner. The computer program product may further be provided as computer program code on a server and downloaded to the receiver 120, e.g. over an internet or an intranet connection.

The terminology used in the description of the embodiments illustrated in the figures is not intended to limit the described methods 700, 900; a transmitter 110 and/or a receiver 120. Various changes, substitutions and/or alterations may be made herein without departing from the invention as defined by the appended claims.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Furthermore, the singular forms "a", "an" and "the" are to be construed as "at least one" and thus may include plural entities of the same kind unless otherwise specified. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, actions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, elements, components, and/or groups thereof. A single unit, such as a processor, may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/provided on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be provided in other forms, such as via the internet or other wired or wireless telecommunication systems.

Claims (28)

1. A method (700) of a transmitter (110) in a wireless communication network (100) for multiplexing data streams (130-:

transmitting (701) data on a plurality of data streams (130-1,130-2), said data to be received by at least one receiver (120);

obtaining (702) a channel quality estimate, wherein the channel quality estimate is channel quality information, CQI;

selecting (703) K data streams (130- < 1 >, 130-2) based on said obtained (702) channel quality estimate;

determining (704) a modulation scheme (400) to be used for the selected (703) K data streams (130-;

forming (705) a binary marker (420) capable of containing bits (b1, b 2...... times, bn) of all K data streams (130-;

determining (706) a value of the formed (705) binary marker (420) by collecting n bits (b1, b 2...... ann, bn) from all K data streams (130- & 1,130-2) according to the mapping;

selecting (707), in the determined (704) modulation scheme (400), constellation points (410) marked according to the determined (706) binary marker (420); and

transmitting (708) data characterizing the selected (707) constellation point (410) in a time-frequency resource element.

2. The method (700) according to claim 1, wherein the mapping is performed dynamically such that the number of times each bit (b1, b 2.. said.. bn) in the formed (705) binary flag (420) is mapped to each selected (703) data stream (130-1,130-2) is similar over a period comprising at least two symbol intervals.

3. The method (700) according to claim 1 or claim 2, wherein the mapping is performed periodically to achieve a similar level of error protection on all selected (703) data streams (130-1,130-2) over a period comprising at least two symbol intervals.

4. The method (700) according to claim 1 or claim 2, wherein the obtained (702) channel quality estimate relates to a channel indirectly pointing to the data stream (130-, "1, 130-2); and selecting (703) the data stream (130- < 1,130-2) when the difference between the obtained (702) channel quality estimates is less than a threshold.

5. The method (700) according to claim 1 or claim 2, wherein K data streams (130-1,130-2) of the plurality of available data streams (130-1,130-2) of Z ≧ K are selected (703); by collecting m from each of said selected (703) K data streams (130-₀One bit (b1, b 2.., bm)₀) Forming (705) the binary mark (420), the formed binary mark (420) having a length m₀K bits (b1, b 2.., bm)₀) (ii) a The determined (704) modulation scheme (400) comprises having

A high order extended constellation of symbols.

6. The method (700) according to claim 1 or claim 2, wherein the transmitter (110) comprises a transmission point, TP, in which the transmission of data (701,708) is in downlink and is to be received by at least one receiver (120) comprising a user equipment, UE.

7. The method (700) according to claim 1 or claim 2, wherein the transmitter (110) comprises a user equipment, UE, wherein the transmission (701,708) of data is in the uplink of the same transmission circuitry (830) and is to be received by at least one receiver (120) comprising a transmission point, TP.

8. The method (700) according to claim 1 or claim 2, wherein the transmitter (110) operates in a time division duplex, TDD, mode, and the act of obtaining (702) a channel quality estimate comprises receiving a signal from the receiver (120) on a reverse link and estimating a channel quality of the received signal.

9. The method (700) according to claim 1 or claim 2, wherein the transmitter (110) operates in a frequency division duplex, FDD, mode or a TDD mode, and the act of obtaining (702) a channel quality estimate comprises receiving a channel quality estimate from the receiver (120).

10. A transmitter (110) in a wireless communication network (100), the transmitter (110) being configured for multiplexing data streams (130-1,130-2) in a multiple access environment, the transmitter (110) comprising:

-a transmitting circuit (830) for transmitting data on a plurality of data streams (130-1,130-2), said data to be received by at least one receiver (120), and for further transmitting data characterizing constellation points (410) in time-frequency resource elements;

-receiving circuitry (810) for obtaining a channel quality estimate, wherein the channel quality estimate is channel quality information, CQI; and

a processor (820) for selecting K data streams (130- < 1 >, 130-2) based on said obtained channel quality estimates; further for determining a modulation scheme (400) to be used for the selected K data streams (130-; further for forming a binary marker (420) capable of containing bits (b1, b 2.. said.. times, bn) of all K data streams (130-; further for determining a value of said formed binary marker (420) by collecting n bits (b1, b 2...... ann, bn) from all K data streams (130-; further for selecting, in the determined modulation scheme (400), constellation points (410) marked according to the determined binary marker (420).

11. The transmitter (110) of claim 10, wherein the processor (820) is further configured to dynamically perform the mapping such that each bit (b1, b 2.... ann.. bn) in the formed binary marker (420) is mapped to each selected data stream (130- "1, 130-2) a similar number of times over a period comprising at least two symbol intervals.

12. The transmitter (110) of claim 10 or claim 11, wherein the processor (820) is further configured to perform the mapping periodically to achieve a similar level of error protection across the selected K data streams (130-1,130-2) over a period comprising at least two symbol intervals.

13. The transmitter (110) according to claim 10 or claim 11, wherein the obtained channel quality estimate relates to a channel that is indirectly directed to the data stream (130-1, 130-2); and the processor (820) is further configured to select K data streams (130- < 1 >, 130-2) when the difference between the received channel quality estimates is less than a threshold.

14. The transmitter (110) according to claim 10 or claim 11, wherein the processor (820) is further configured to select K data streams (130- "1, 130-" 2 ") of the plurality of available data streams (130-" 1,130- "2") of Z ≧ K; the processor (820) is further configured to collect m from each of the selected K data streams (130- < 1 >, 130-2)₀One bit (b1, b 2.., bm)₀) Forming the binary mark (420), the formed binary mark (420) having a length of m₀K bits (b1, b 2.., bm)₀) (ii) a The processor (820) is configured to determine whether to include having

A modulation scheme (400) of a high order spread constellation of symbols.

15. The transmitter (110) according to claim 10 or claim 11, wherein the transmitter (110) comprises a transmission point, TP, wherein the transmission of data is in downlink and is to be received by at least one receiver (120) comprising a user equipment, UE.

16. The transmitter (110) according to claim 10 or claim 11, wherein the transmitter (110) comprises a user equipment, UE, wherein the transmission of data is in uplink and is to be received by at least one receiver (120) comprising a transmission point, TP.

17. The transmitter (110) of claim 10 or claim 11, wherein the transmitter (110) operates in a TDD mode and is configured to receive a signal from the receiver (120) on a reverse link and to estimate a channel quality of the received signal.

18. The transmitter (110) according to claim 10 or claim 11, wherein the transmitter (110) operates in FDD mode or TDD mode and is configured to receive the channel quality estimate from the receiver (120).

19. A method (900) of a receiver (120) in a wireless communication network (100) for receiving at least one multiplexed data stream (130-, "130-2") in a multiple access environment, the method (900) comprising:

receiving (901) data transmitted by a transmitter (110) on at least one data stream (130-1, 130-2);

determining (904) a modulation scheme (400) to be used for the received (901) data stream (130- < 1 >, < 130-2) based on an estimated channel quality, being a channel quality information, CQI, or transmission parameter signalling information received from the transmitter (110);

receiving (905) data characterizing a constellation point (410) in a time-frequency resource element;

demapping (906) the received (905) data by determining which bits (b1, b 2.. once.bn) of a binary flag (420) corresponding to the constellation point (410) are associated with the data streams (130-1,130-2), wherein each bit of the binary flag (420) is mapped with the data streams (130-1,130-2) such that the data streams (130-1,130-2) have similar error protection levels.

20. The method (900) of claim 19, wherein the receiver (120) operates in a TDD mode.

21. The method (900) according to claim 19 or claim 20, wherein the receiver (120) operates in FDD mode or TDD mode, wherein the method (900) further comprises:

estimating (902) a channel quality related to a channel associated with said received (901) data stream (130-;

-transmitting (903) the estimated (902) channel quality, which estimated (902) channel quality is to be received by the transmitter (110).

22. The method (900) according to claim 19 or claim 20, wherein the receiver (120) comprises a UE; the receiving (901) is performed in downlink with data transmitted by a transmitter (110) comprising a TP.

23. The method (900) according to claim 19 or claim 20, wherein the receiver (120) comprises a TP; the receiving (901) is performed in uplink by data transmitted by a transmitter (110) comprising the UE.

24. A receiver (120) in a wireless communication network (100) for receiving at least one multiplexed data stream (130-1,130-2) in a multiple access environment, the receiver (120) comprising:

-receiving circuitry (1010) for receiving data characterizing constellation points (410) in time-frequency resource elements; the receiving circuit (1010) is further configured to receive data transmitted by the transmitter (110) over at least one data stream (130- < 1 >, 130-2);

a processor (1020) for determining a modulation scheme (400) to be used for the received data stream (130-.

25. The receiver (120) according to claim 24, wherein the receiver (120) is configured to operate in a TDD mode.

26. The receiver (120) according to claim 24 or claim 25, wherein the receiver (120) is configured to operate in FDD mode or TDD mode, and wherein the processor (1020) is further configured to estimate a channel quality related to a channel associated with the received data stream (130-1, 130-2); the receiver (120) further comprises a transmitting circuit (1030) for transmitting the estimated channel quality to be received by the transmitter (110).

27. The receiver (120) according to claim 24 or claim 25, wherein the receiver (120) comprises a UE; the receiving is performed in downlink with data transmitted by a transmitter (110) comprising the TP.

28. The receiver (120) according to claim 24 or claim 25, wherein the receiver (120) comprises a TP; the receiving is performed in uplink by data transmitted by a transmitter (110) comprising the UE.

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