# US 2013/0157660 A1 · Communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157660 A1 - Document ID: US20130157660A1 - Status: Published application - Kind: A1 - Application number: 13/818,294 - Filed: 2012-07-25 - Published: 2013-06-20 - Earliest claimed: 2011-07-25 - Assignees: NEC Corporation - Inventors: Yassin Aden Awad; Yasushi Maruta; Toshifumi Sato - Web page: https://patentgrep.com/patent/US20130157660A1 ## CPC - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04L 5/0023: {Time-frequency-space} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W 72/20: Control channels or signalling for resource management - H04W 16/28: using beam steering - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A communication system is presented in which a base station is provided for communicating with a plurality of mobile communication devices in a cellular communication system. The base station operates one of more communication cells and communicates subframes, with each of the plurality of communication devices within the cell(s), each comprising the communication resources of a control region for communicating a control channel and the communication resources of a data region for communicating a respective data channel. The base station communicates a control channel having a first DMRS sequence in a control region of some subframes and a control channel having a second DMRS sequence in a control region of other subframes. The second control channel may be transmitted in a radio beam focussed spatially in a direction of a communication device. The first control channel may be transmitted omnidirectionally throughout the cell(s). ## Claims ### Claim 1 Communication apparatus for communicating with a plurality of mobile communication devices in a cellular communication system said communication apparatus comprising: means for operating at least one communication cell; means for communicating, via a plurality of antenna ports, a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said communicating means is operable to communicate: first control information using a first reference signal pattern and using a first antenna port; and second control information using a second reference signal pattern and using a second antenna port. ### Claim 2 A communication device for communicating with communication apparatus of a cellular communication system said communication device comprising: means for registering said communication device in at least one communication cell operated by said communication apparatus; means for receiving a plurality of sub-frames transmitted from said communication apparatus via a plurality of antenna ports, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said receiving means is operable: first control information communicated using a first reference signal pattern and using a first antenna port by said communication apparatus; and second control information communicated using a second reference signal pattern and using a second antenna port by said communication apparatus; and means for interpreting said control information communicated using said first reference signal pattern, and for interpreting control information communicated using said second reference signal pattern. ### Claim 3 Communication apparatus for communicating with a plurality of mobile communication devices in a cellular communication system said communication apparatus comprising: means for operating at least one communication cell; means for communicating a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said communicating means is operable to communicate: a first control channel having a first reference signal pattern in a control region of a first of said subframes; and a second control channel having a second reference signal pattern in a control region of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern. ### Claim 4 (depends on 3) Communication apparatus according to claim 3 wherein said means for operating at least one communication cell is operable to operate a first cell using a first component carrier and a second cell using a second component carrier, and wherein said first subframe is provided using said first component carrier and said second subframe is provided using said second component carrier. ### Claim 5 (depends on 4) Communication apparatus according to claim 4 wherein said second component carrier is operated as an extension carrier. ### Claim 6 (depends on 4) Communication apparatus according to claim 4 wherein said first component carrier is operated as a stand-alone carrier. ### Claim 7 (depends on 3) Communication apparatus according to claim 3 wherein said communicating means is operable to focus said second control channel spatially in a direction of a specific communication device. ### Claim 8 (depends on 3) Communication apparatus according to claim 3 wherein said communicating means is operable to transmit said first control channel omnidirectionally throughout said at least one cell. ### Claim 9 (depends on 3) Communication apparatus according to claim 3 further comprising means for determining whether a specific communication device should receive a first control channel having said first reference signal pattern, or a second control channel having said second reference signal pattern. ### Claim 10 (depends on 9) Communication apparatus according to claim 9 wherein said determining means is operable to determine whether said specific communication device should receive said first control channel having said first reference signal pattern, or said second control channel having said second reference signal pattern, based on a location of said communication device. ### Claim 11 (depends on 10) Communication apparatus according to claim 10 wherein said determining means is operable to determine whether said specific communication device should receive said first control channel having said first reference signal pattern, or said second control channel having said second reference signal pattern, based on the location of said communication device relative to further communication apparatus. ### Claim 12 (depends on 11) Communication apparatus according to claim 11 wherein said determining means is operable to determine the location of said communication device relative to said further communication apparatus based on a result of a measurement of a parameter representing a distance of said communication device from said further communication apparatus. ### Claim 13 (depends on 12) Communication apparatus according to claim 12 wherein said parameter representing a distance of said communication device from said further communication apparatus comprises a reference signal received power (RSRP) of a signal transmitted by said further communication apparatus. ### Claim 14 (depends on 9) Communication apparatus according to claim 9 wherein said determining means is operable to determine that said specific communication device should receive said first control channel having said first reference signal pattern if a predefined message has been received from the specific communication device. ### Claim 15 (depends on 9) Communication apparatus according to claim 9 wherein said determining means is operable to determine that said specific communication device should receive said second control channel having said second reference signal pattern if a further predefined message has been received from the specific communication device. ### Claim 16 (depends on 9) Communication apparatus according to claim 9 wherein said determining means is operable to determine whether said specific communication device should receive a said first control channel having said first reference signal pattern, or said second control channel having said second reference signal pattern, in dependence on a measurement report received from the specific communication device. ### Claim 17 (depends on 3) Communication apparatus according to claim 3 wherein said communication apparatus comprises a plurality of distributed antennas. ### Claim 18 (depends on 17) Communication apparatus according to claim 17 wherein said communicating means is operable to communicate said first control channel having a first reference signal pattern using any of said plurality of antennas. ### Claim 19 (depends on 17) Communication apparatus according to claim 17 wherein said communicating means is operable to communicate said second control channel having a second reference signal pattern using a subset comprising at least one, but not all, of said plurality of antennas. ### Claim 20 (depends on 17) Communication apparatus according to claim 17 wherein said communicating means is operable to communicate a control channel having a third reference signal pattern in a third of said subframes using a subset comprising at least one, but not all, of said plurality of antennas, wherein said third reference signal pattern is different from first reference signal pattern and said second reference signal pattern. ### Claim 21 (depends on 3) Communication apparatus according to claim 3 wherein said communicating means is operable to communicate radio frames comprising a plurality of subfames, each subframe having a different respective subframe location, and wherein said communicating means is operable: to communicate said first control channel having a first reference signal pattern in a subframe at a subframe location, within a radio frame, selected from a first set of subframe location(s) comprising at least one subframe location; and to communicate said second control channel having a second reference signal pattern in a subframe at a subframe location, within a radio frame, selected from a second set of subframe location(s) comprising at least one subframe location; wherein said first set of subframe location(s) does not comprise the same subframe location(s) as said second set of subframe location(s). ### Claim 22 (depends on 3) Communication apparatus according to claim 3 wherein said first control channel having a first reference signal pattern is not communicated in a subframe at a subframe location of a multi-media broadcast over a single frequency network (MBSFN) subframe and/or is not communicated in a subframe at a subframe location of an almost blank subframe (ABS). ### Claim 23 (depends on 3) Communication apparatus according to claim 3 wherein said second control channel having a second reference signal pattern is communicated in a subframe at a subframe location of a multi-media broadcast over a single frequency network (MBSFN). ### Claim 24 (depends on 3) Communication apparatus according to claim 3 wherein said second control channel having a second reference signal pattern is communicated in a subframe of an almost blank subframe (ABS). ### Claim 25 (depends on 3) Communication apparatus according to claim 3 wherein control information communicated using said first and/or said second represents a resource allocation for a communication device. ### Claim 26 (depends on 3) Communication apparatus according to claim 3 wherein each said reference signal pattern comprises a demodulation reference signal pattern ‘DMRS’. ### Claim 27 A communication device for communicating with communication apparatus of a cellular communication system said communication device comprising: means for registering said communication device in at least one communication cell operated by said communication apparatus; means for receiving a plurality of sub-frames from said communication apparatus, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said receiving means is operable: to receive a first control channel having a first reference signal pattern in a control region of a first of said subframes; and to receive a second control channel having a second reference signal pattern in a in a control region of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern; and means for interpreting control information communicated in said first control channel having a first reference signal pattern, and for interpreting control information communicated in said second control channel having a second reference signal pattern. ### Claim 28 (depends on 27) A communication device according to claim 27 wherein said receiving means is operable to receive said first subframe on a first component carrier of a first frequency band and said second subframe on a said second component carrier of a second frequency band. ### Claim 29 (depends on 28) A communication device according to claim 28 wherein said second component carrier is operated as an extension carrier. ### Claim 30 (depends on 28) A communication device according to claim 28 wherein said first component carrier is operated as a stand-alone carrier. ### Claim 31 (depends on 27) A communication device according to claim 27 wherein said receiving means is operable to receive said second control channel in a radio beam focussed spatially in a direction of said communication device. ### Claim 32 (depends on 27) A communication device according to claim 27 wherein said receiving means is operable to receive said first control channel in a radio communication transmitted omnidirectionally throughout said at least one cell. ### Claim 33 (depends on 27) A communication device according to claim 27 further comprising means for measuring a parameter representing a distance of said communication device from further communication apparatus. ### Claim 34 (depends on 33) A communication device according to claim 33 wherein said parameter representing a distance of said communication device from said further communication apparatus comprises a reference signal received power (RSRP) of a signal transmitted by said further communication apparatus. ### Claim 35 (depends on 33) A communication device according to claim 33 further comprising means for transmitting a predefined message to said communication apparatus operating said cell in dependence on a result of said measurement of said parameter representing a distance of said communication device from said further communication apparatus. ### Claim 36 (depends on 35) A communication device according to claim 35 wherein said predefined message comprises a measurement report including said result of said measurement. ### Claim 37 (depends on 35) A communication device according to claim 35 wherein said predefined message comprises information representing an identity of said further communication apparatus and/or of a cell operated by said further communication apparatus. ### Claim 38 (depends on 35) A communication device according to claim 35 further comprising means for comparing said parameter against a predetermined threshold value. ### Claim 39 (depends on 38) A communication device according to claim 38 wherein said transmitting means is operable to transmit said predefined message if said comparison indicates that said parameter has risen above said threshold value. ### Claim 40 (depends on 38) A communication device according to claim 38 wherein said transmitting means is operable to transmit a further predefined message if said comparison indicates that said parameter has fallen below said threshold value. ### Claim 41 (depends on 23) A communication device according to claim 23 wherein said receiving means is operable to receive radio frames comprising a plurality of subfames, each subframe having a different respective subframe location within the radio frame, and wherein said receiving means is operable: to receive a first control channel having a first reference signal pattern in a subframe at a subframe location, within a radio frame, selected from a first set of subframe location(s) comprising at least one subframe location; and to receive a second control channel having a second reference signal pattern in a subframe at a subframe location, within a radio frame, selected from a second set of subframe location(s) comprising at least one subframe location; wherein said first set of subframe location(s) does not comprise the same subframe location(s) as said second set of subframe location(s). ### Claim 42 (depends on 27) A communication device according to claim 27 wherein said first control channel having a first reference signal pattern is not received in a subframe at a subframe location of a multi-media broadcast over a single frequency network (MBSFN) and/or is not received in a subframe at a subframe location of an almost blank subframe (ABS). ### Claim 43 (depends on 27) A communication device according to claim 27 wherein said second control channel having a second reference signal pattern is received in a subframe at a subframe location of a multi-media broadcast over a single frequency network (MBSFN). ### Claim 44 (depends on 27) A communication device according to claim 27 wherein said second control channel having a second reference signal pattern is received in a subframe of an almost blank subframe (ABS). ### Claim 45 (depends on 27) A communication device according to claim 27 wherein said control information communicated using said first and/or said second represents a resource allocation for the communication device. ### Claim 46 (depends on 27) A communication device according to claim 27 wherein each said reference signal pattern comprises a demodulation reference signal pattern ‘DMRS’. ### Claim 47 A method, performed by communication apparatus, for communicating with a plurality of mobile communication devices in a cellular communication system, the method comprising: operating at least one communication cell; communicating, via a plurality of antenna ports, a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; communicating first control information using a first reference signal pattern and using a first antenna port; and communicating second control information using a second reference signal pattern and using a second antenna port. ### Claim 48 A method, performed by a communication device for communicating with communication apparatus of a cellular communication system, the method comprising: registering said communication device in at least one communication cell operated by said communication apparatus; receiving a plurality of sub-frames transmitted from said communication apparatus via a plurality of antenna ports, wherein each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; receiving first control information communicated using a first reference signal pattern and using a first antenna port by said communication apparatus; interpreting said control information communicated using said first reference signal pattern; receiving second control information communicated using a second reference signal pattern and using a second antenna port by said communication apparatus; and interpreting control information communicated using said second reference signal pattern. ### Claim 49 A method, performed by communication apparatus, of communicating with a plurality of mobile communication devices in a cellular communication system said method comprising: operating at least one communication cell; communicating a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; communicating control information using a first control channel having a first reference signal pattern in a control region of a first of said subframes; and communicating control information using a second control channel having a second reference signal pattern in a control region of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern. ### Claim 50 A method, performed by a communication device, of communicating with communication apparatus of a cellular communication system said method: registering said communication device in at least one communication cell operated by said communication apparatus; receiving a plurality of sub-frames from said communication apparatus, wherein each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; receiving a first control channel having a first reference signal pattern in a control region of a first of said subframes; interpreting control information communicated in said first control channel having a first reference signal pattern; receiving a second control channel having a second reference signal pattern in a in a control region of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern; and interpreting control information communicated in said second control channel having a second reference signal pattern. ### Claim 51 (depends on 3) A computer program product comprising instructions operable to program a programmable processor to implement communication apparatus according to claim 3. ### Claim 52 Communication apparatus for communicating with a plurality of mobile communication devices in a cellular communication system said communication apparatus comprising: means for operating at least one communication cell; means for communicating a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said communicating means is operable to communicate: control information using a first control channel having a first reference signal pattern in a control region of a first of said subframes; and control information using a second control channel having a second reference signal pattern in one of said control and data regions of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern. ### Claim 53 A communication device for communicating with communication apparatus of a cellular communication system said communication device comprising: means for registering said communication device in at least one communication cell operated by said communication apparatus; means for receiving a plurality of sub-frames from said communication apparatus, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said receiving means is operable: to receive a first control channel having a first reference signal pattern in a control region of a first of said subframes; and to receive a second control channel having a second reference signal pattern in at least one of a control region and a data region of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern; and means for interpreting control information communicated in said first control channel having a first reference signal pattern, and for interpreting control information communicated in said second control channel having a second reference signal pattern. ### Claim 54 Communication apparatus for communicating with a plurality of mobile communication devices in a cellular communication system said communication apparatus comprising: means for operating at least one communication cell; means for communicating a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein: said communicating means is operable to communicate: control information using a first control channel omnidirectionally throughout said cell; and control information using a second control channel in a direction spatially focussed towards a communication device for which the control information is intended. ### Claim 55 A communication device for communicating with communication apparatus of a cellular communication system said communication device comprising: means for registering said communication device in at least one communication cell operated by said communication apparatus; means for receiving a plurality of sub-frames from said communication apparatus, wherein: said receiving means is operable: to receive a first control channel omnidirectionally by the communication apparatus throughout said cell; and to receive a second control channel transmitted in a direction spatially focussed towards said communication device; and means for interpreting control information communicated in said first control channel, and for interpreting control information communicated in said second control channel. ### Claim 56 Communication apparatus for communicating with a plurality of mobile communication devices in a cellular communication system said communication apparatus comprising: a cell controller adapted to operate at least one communication cell; a transceiver operable to communicate a plurality of subframes with each of a plurality of communication devices within said at least one cell, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said transceiver is further operable to communicate: control information using a first control channel having a first reference signal pattern in a control region of a first of said subframes; and control information using a second control channel having a second reference signal pattern in at least one of said control and data regions of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern. ### Claim 57 A communication device for communicating with communication apparatus of a cellular communication system said communication device comprising: a cell registration module operable to register said communication device in at least one communication cell operated by said communication apparatus; a transceiver operable to receive a plurality of sub-frames from said communication apparatus, wherein: each sub-frame comprises a plurality of communication resources defining a control region for communicating a respective control channel and a plurality of communication resources defining a data region for communicating a respective data channel; and said transceiver is further operable: to receive a first control channel having a first reference signal pattern in a control region of a first of said subframes; and to receive a second control channel having a second reference signal pattern in at least one of said control region and said data region of a second of said subframes, wherein said second reference signal pattern is different from said first reference signal pattern; and a processor operable to interpret control information communicated in said first control channel having a first reference signal pattern, and to interpret control information communicated in said second control channel having a second reference signal pattern. ### Claim 58 (depends on 27) A computer program product comprising instructions operable to program a programmable processor to implement a communication device according to claim 27.