Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/0001—Arrangements for dividing the transmission path
  • H04L5/0003—Two-dimensional division
  • H04L5/0005—Time-frequency
  • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0037—Inter-user or inter-terminal allocation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L27/00—Modulated-carrier systems
  • H04L27/0006—Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L27/00—Modulated-carrier systems
  • H04L27/26—Systems using multi-frequency codes
  • H04L27/2601—Multicarrier modulation systems
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/04—Protocols for data compression, e.g. ROHC

Definitions

• the invention relates to a multi-carrier compressed sensing multi-user system.
• machine-type communication which finds a form in machine-to-machine communication (also referred to as machine-to-machine communication or M2M for short). This is often described as the Internet of Things.
• FIG. 1 shows a typical scenario in which a plurality of terminals ⁇ 1; UE 2 , UE 3 , ... UE K communicate with a central station BSS via an unspecified transmission medium. That is, the system is a multi-user system.
• a terminal UE ⁇ UE 2 would first secure access to a data transmission medium.
• this can be done, for example, via an Access Reservation via a control channel.
• a Scheduied Access Request may also be used.
• the secure receipt of an Access Reservation is signaled by a Reservation Ack or the granting of an Access Request by an Ack to the respective terminal.
• each available bandwidth B is often only one terminal available.
• FIG. 1 shows an exemplary situation of a communication system in which the invention can be used
• FIG. 7 shows an exemplary schematic division of steps according to embodiments of the invention with respect to base stations according to the invention.
• the invention is described below with respect to 3 rd Generation Partnership Project (3GPP) communication systems, the invention is not limited to these communication systems. In particular, the invention is applicable to all multi-carrier transmission systems having a plurality of users.
• 3GPP 3 rd Generation Partnership Project
• the invention relates to physical access to the transmission medium.
• multi-carrier transmission is also used in other wired systems such as DSL or Powerline, as well as in other wireless systems such as WLAN (eg IEEE 802.1 1 a / g / n), WiMax (eg IEEE 802.16.2-2004) or Bluetooth.
• WLAN eg IEEE 802.1 1 a / g / n
• WiMax eg IEEE 802.16.2-2004
• Bluetooth eg IEEE 802.16.2-2004
• the base station BSS is comparable with respect to the communication of a central station as described above.
• the data to be transmitted is transmitted in the frequency domain rather than in the time domain.
• terminals UE 1; UE 2 , ... simultaneously access the same transmission medium.
• terminals UEi, UE 2 , ... can use the same physical resource (time and frequency).
• FIG. 1 A typical procedure of access of a terminal UEi is shown in FIG.
• the terminal UEi transmits directly, i. without prior allocation of the medium, its data to the base station BSS. If this successful recorded depending on the nature of the connection protocol confirmation Ack be sent back from the base station BSS to the terminal UEi (connection-oriented, confirmed) or such a message can be omitted (connectionless, unconfirmed).
• Such access can also be referred to as direct random access.
• a message can be omitted.
• the terminal UEi is capable, e.g. in a connection-oriented setup, resending the message after waiting to see if a confirmation Ack was received.
• MCM multi-carrier modulation
• terminal UE ⁇ UE 2 use the terminal UE ⁇ UE 2 ; ... at least one subset M 1 each ; M 2 , ... of carriers of the set N of carriers. That is, terminal UEi uses subset M 1; Terminal UE 2 uses subset M 2 , etc.
• the respective subsets always represent only a part of the total amount N of carriers, ie M 1 applies ; M 2 ⁇ N.
• a first terminal DE ⁇ uses a first subset Mi of bearers and a second terminal UE 2 uses a second subset M 2 of bearers, wherein at least one bearer of the first subset I ⁇ is also part of the second subset M 2 ,
• each UE UE would have UE 2 ; ... allocates the full bandwidth and distributes the data to the frequency domain. This is a considerable effort driven in view of the small amount of data, because the resource bandwidth is busy by a single terminal, the bandwidth is actually not needed. Since the full bandwidth is used, the frequency response of the physical channel, that is, the transfer function, must also be determined at the receiver. This is a complex task that requires a lot of effort.
• an MCSM system which requires the bandwidth of a terminal UE ⁇ UE 2 ; ... corresponds, due to the smaller number of carriers M 1; M 2 , ... a significantly lower bandwidth than a system of the prior art.
• the signals are perceived as sparse (engl, sparse).
• This characteristic of the signals - the "sparse" nature of the signals - is caused by a low level of activity of the terminals UE 1, UE 2 , eg of sensors, so that at a certain time only a small amount of the entire terminals UE 2 , UE 2 , ... is active, as can be seen for example in Fig.1.
• the base station BSS by means of Compressed Sensing Multiuser Detection (CS-MUD) a transmission of the terminal UE ⁇ UE 2 ; ... detect from the plurality of received quantities N of carriers.
• CS-MUD Compressed Sensing Multiuser Detection
• the number of carriers of subsets M 1; M2, ... does not necessarily have to be identical.
• the number of carriers may also take into account considerations of the amount of data to be transmitted, the data rate, the transmission security, etc., higher layer requirements in the ISO / OSI model, etc.
• the principle of Compressed Sensing Multiuser Detection is not limited to subsets M 1; M 2 , ... ⁇ N, but the principle can equally be applied to M, M 2 , ... ⁇ N.
• the carriers can at least one of the subset M 1; M2, ... to be adjacent.
• FIG. 6 shows an exemplary use of the bandwidth B in FIG Comparison to the prior art with respect to a time-frequency grid in an exemplary CDMA system.
• terminal l) E- ⁇ could use the bandwidth component Bi corresponding to a multicarrier Compressed Sensing Multi-User System MCSMi, while another Terminal UE 2 here uses the bandwidth portion B 2 corresponding to a multi-carrier Compressed Sensing Multi-User System MCSM 2 , that is, the respective terminal UE ⁇ UE 2 ; ... can record parallel to the base station BSS at the same time.
• the terminals UE 1; UE 2 the same subcarriers and thus the same bandwidth, ie the terminal UE 1; UE 2 use the same physical resource (time-frequency resource). Since both terminal UE 1; UE 2 are in a system, is saved by the over-the-prior art multiple allocation of resources bandwidth. This allows a significant increase in granularity with low complexity and more efficient bandwidth utilization.
• An exemplary base station receiver BSS-RX for such a multi-carrier Compressed Sensing Multi-User System is accordingly set up, as shown by way of example in FIG. 7, for receiving the set N of carriers.
• This reception does not differ from conventional systems and may be designed in accordance with a typical multi-carrier processing in the MT processing block and e.g. provide a conversion of the data from the time domain into the frequency domain.
• the subset M 1; M 2 , ... are processed by carriers of the set N of carriers by means of compressed sensing multiuser detection in the block CS-MUD.
• the processing is possible in any way, ie it can be a parallel processing of different partial transmission systems MCSM 1; MCSM 2 , ... corresponding to the terminals UE ⁇ UE 2 ; ... or a serial processing or mixed forms thereof.
• the base station BSS by means of Compressed Sensing Multiuser Detection (CS-MUD) a transmission of the terminal UE ⁇ UE 2 ; ... detect from the plurality of received quantities N of carriers.
• CS-MUD Compressed Sensing Multiuser Detection
• the characteristic of typical machine communication is used that a typical terminal is only sporadically active, so that usually even with a high number of terminals only a (small) fraction sends data at a given time.
• Such sporadic use can also be understood as sparsely populated multiuser signals (English, sparse multiuser signals) at the base station BSS.
• a set N of carriers are received. Subsequently, from at least one subset M 1; M 2 , ... the amount N of carriers by means of Compressed Sensing Multiuser Detection (CS-MUD) a transmission of a terminal UE ⁇ UE 2 ; ... detected from the plurality of received quantities N of carriers.
• CS-MUD Compressed Sensing Multiuser Detection
• the detection step can readily provide both activity detection and data estimation from a sparsely populated multi-user signal.
• an activity detection may first be carried out, eg MCSM 3 is active, and subsequently the carrier N, the compressed sensing (CS), will be applied at least to the subset M 3 affected thereby.
• Compressed sensing is a method of signal processing that allows to efficiently obtain and reconstruct a signal by finding solutions to an underdetermined linear system. In doing so, it is exploited that by optimization in terms of sparseity it is sufficient to evaluate considerably fewer samples than would otherwise be expected from the Shannon-Nyquist sampling theorem.
• the reception can now be performed as shown in FIG. 3 by sending an acknowledgment ACK to the terminal UE 1, UE 2 ; ... are reported and thus indicated that the sending was successful.
• At least a subset M 1; M 2 , ... are chosen from carriers of the set N of carriers, where M 1; M2 ⁇ N is.
• the selection can be made by a higher one Layer (in the ISO / OSI model) previously determined or negotiated and is not necessary for the further understanding of the invention.
• the data to be sent by the terminal can be modulated in a block mod to a plurality of (logical) carriers in a block spread and split them by means of a block map to the subset M 1; M 2 , ... are distributed by (physical) carriers of the set N of carriers.
• a block mod to a plurality of (logical) carriers in a block spread and split them by means of a block map to the subset M 1; M 2 , ... are distributed by (physical) carriers of the set N of carriers.
• the thus modulated and distributed data can be sent to the base station BSS.
• the received reception can now be reported by the base station BSS as shown in FIG. 3 by receiving an acknowledgment ACK and thus indicating that the transmission was successful.
• the terminal UE 1; UE 2 before sending first tries to detect activity on one or more carriers of the set N of carriers.
• This can be used, for example, the channel quality in the corresponding bandwidth B 1; B 2 , ... B k , and / or the selection of a subset M 1; M 2 , ... or in general to receive the permission to send in case of inactivity on the appropriate bandwidth.
• the invention can be used particularly advantageously if the bandwidth of the subset M 1; M 2 , ... of carriers of the set N of carriers is less than or equal to the coherence bandwidth B c of the (sub-) channel.
• the coherence bandwidth B c (in hertz) can be expressed by B c «-! -
• r max is the time difference between the beginning and the end of the channel impulse response. This is also known as the delay spread.
• the system also allows the subset M to be varied, ie to use a subset M - 1 for a first broadcast and a different subset M 2. For a second subset. In this way reference to the time diversity can be obtained.
• the invention can be applied to a wide variety of wireless or wired systems. However, it is particularly suitable for use in a wireless communication system, and in particular for use in a UMTS, LTE, 5th Generation mobile radio system, WiFi, or iDEN communication system.
• the invention can be used in any multi-carrier scheme, in particular orthogonal multi-carrier schemes in combination with CDMA, also referred to as MC / OFDM-CDMA, may serve as the basis.
• the invention may find application as follows. From the typically present N carriers for a normal bandwidth B, a subset M is formed. The modulated data is then mapped onto M subcarriers by means of a spreading sequence. For example, in a CDMA (Code Division Multiple Access) system, the CDMA sequences in the frequency domain (transmitter side) are applied to only the subset M. The receiver side uses Compressed Sensing - Multi User Detection, exploiting the characteristic that the signal appears sparse.
• CDMA Code Division Multiple Access
• the modulation scheme actually used for this carrier can now be chosen non-coherently, since the bandwidth of the subset used is smaller or smaller equal to the coherence bandwidth B c can be selected. This can dramatically simplify or eliminate channel estimation.
• the channel estimation may even be omitted.
• the available bandwidth is used better than in the conventional system, since a multiplicity of terminals UE 1, UE 2 ; ... with a base station BSS corresponding sub-systems MCSM ⁇ MCSM 2 ; ... and thus make better use of the entire bandwidth B, since they can now communicate in parallel with the base station.
• a CDMA system for example, also makes it possible to dynamically allocate the time-frequency grid.
• the system according to the invention is also designed as a random access system as shown in FIG. 3, the message overhead (control signaling) decreases, thereby also enabling improved bandwidth utilization.

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• Engineering & Computer Science (AREA)
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• Computer Networks & Wireless Communication (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Computer Security & Cryptography (AREA)
• Mobile Radio Communication Systems (AREA)

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• 2015
  • 2015-05-06 LU LU92709A patent/LU92709B1/en active
• 2016
  • 2016-05-04 WO PCT/EP2016/060064 patent/WO2016177815A1/de active Application Filing
  • 2016-05-04 EP EP16724322.9A patent/EP3292649A1/de not_active Withdrawn
  • 2016-05-04 US US15/571,905 patent/US20180139019A1/en not_active Abandoned
  • 2016-05-04 CN CN201680031259.XA patent/CN107690767A/zh active Pending

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