Pilot structure with multiplexed unicast and sfn transmissions

“METHOD FOR TRANSMITTING A SET OF PILOT SIGNALS WITH MULTIPLEXED UNIDIFUSION AND MULTI-DIFFUSION TRANSMISSIONS, WIRELESS COMMUNICATION EQUIPMENT THAT FACILITIES TRANSMITTING A MULTIPLEXED PILOT SIGNAL WITH TRANSMISSIONS BY MULTIDIFUSION AND A UNMISSIONABLE MEMORY IN EYE UNMISSIONABLE MEMORIAL IN EFFICIENT MEMORY AND EFFICIENT MEMORY IN DEMANDED DEMANDING.

I. FIELD

[001] The description that follows refers generally to communications systems and more particularly to the provision of a pilot structure in multiplexed, single-frequency and single-broadcast network transmissions. II. Fundamentals [002] Wireless communication systems are widely used to provide various types of communication content, such as voice, data and so on. Typical wireless communication systems can be multiple access systems capable of supporting communication with multiple users by sharing system resources (for example, bandwidth, transmission power, ...). Examples of such multiple access systems may include code division multiple access systems (CDMA), time division multiple access systems (TDMA), frequency division multiple access systems (FDMA), multiple access systems by orthogonal frequency division (OFDMA) and the like.

[003] Generically, multiple access communication systems can simultaneously support communication to multiple mobile devices. Each mobile device can communicate with one or more base stations via forward and reverse link transmissions. The direct link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. In addition, communications between mobile devices and base stations can be established via single-entry and single-exit (SISO) systems, multiple-entry and single-exit (MISO) systems, multiple-entry and multiple-exit systems ( MIMO) and so on.

[004] MIMO systems commonly employ multiple transmit antennas (NT) and multiple receive antennas (NR) for data transmission. A MIMO channel formed by the NT transmission and NR reception antennas can be decomposed into independent NS channels, which can be referred to as spatial channels, where Ns <{Nt, Nr}. Each of the NS independent channels corresponds to a dimension. In addition, MIMO systems can provide improved performance (for example, increased spectral efficiency, higher transmission capacity and / or greater reliability) if the additional dimensions created by the multiple transmit and receive antennas are used.

[005] MIMO systems can support several duplexing techniques to divide direct and reverse link communications through a common physical medium. For example, duplex frequency division (FDD) systems can use different frequency regions for forward or reverse link communications. In addition, in duplex time division (TDD) systems, forward and reverse link communications can employ a common frequency region. However, conventional techniques can provide limited feedback or no feedback related to channel information.

SUMMARY

[006] The following provides a simplified summary of one or more modalities to provide a basic understanding of such modalities. This summary is not an extensive overview of all the modalities considered, and is not intended to identify key or critical elements of all modalities or to outline the scope of all or any modalities. Its sole purpose is to present some concepts of one or more modalities in a simplified form as a prelude to the more detailed description that is presented later.

[007] In one aspect, a method for transmitting a pilot signal with multiplexed multicast and multicast transmissions in the present invention. The method may comprise classifying one or more modes of transmission. In addition, the method may include selecting a cyclic prefix duration for at least one subframe according to one or more classified modes. The method may also comprise multiplexing pilot information and user data in at least one subframe based at least in part on the selected cyclic prefix duration.

[008] Another aspect refers to a Equipment for wireless communication that comprises a memory that holds instructions related to the classification of one or more transmission modes, selecting a longer cyclic prefix duration for at least one subframe according to a or more classified modes and multiplex pilot information and user data in at least one subframe based at least in part on the longest cyclic prefix duration. Wireless communication equipment may also include a memory-attached processor, configured to execute instructions held in memory.

[009] Yet another aspect refers to Equipment for wireless communication that facilitates the transmission of a multiplexed pilot signal with multicast transmissions. The equipment may include means for classifying one or more modes of transmission. In addition, the equipment may include means for selecting a longer cyclic prefix duration for at least one subframe according to one or more classified modes. The equipment may further comprise means for multiplexing pilot information and user data in at least one subframe based at least in part on the longer duration of the cyclic prefix.

[0010] Yet another aspect refers to a machine-readable medium having stored executable instructions per machine to classify one or more modes of transmission. The machine-readable medium may further comprise instructions for selecting a longer duration of cyclic prefix for at least one subframe according to one or more classified modes. In addition, the machine-readable medium may include instructions for multiplexing pilot information and user data in at least one subframe based at least in part on the longest cyclic prefix duration.

[0011] According to another aspect, in a wireless communication system, an equipment can comprise an integrated circuit. The integrated circuit can be configured to classify one or more transmission modes. The integrated circuit can be further configured to select a longer cyclic prefix duration for at least one subframe according to one or more classified modes. In addition, the integrated circuit can be configured to multiplex pilot information and user data in at least one subframe based at least in part on the longest cyclic prefix duration.

[0012] For the realization of the above and related purposes, one or more modalities comprises the characteristics now fully described and particularly indicated in the claims. The following description and attached drawings set out in detail certain illustrative aspects of one or more modalities. These aspects are indicative, however, of just some of the various ways in which the principles of various modalities can be employed and the modalities described are intended to include all of these aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is an illustration of a wireless communication system according to several aspects exposed here.

[0014] Figure 2 is an illustration of an example communication equipment for use in a communication system without according to one aspect of the present disclosure.

[0015] Figure 3 is an illustration of a wireless communication system according to one aspect of the present disclosure.

[0016] Figures 4-10 are illustrations of an example of resource mappings according to one aspect of the present disclosure.

[0017] Figure 11 is an illustration of an example methodology that facilitates the provision of a pilot structure in multiplexed multicast and multicast transmissions with longer cyclic prefix durations according to one aspect of the present disclosure.

[0018] Figure 12 is an illustration of an example mobile device that facilitates employing a pilot structure in mixed mode transmissions.

[0019] Figure 13 is an illustration of an example system that facilitates the construction of a pilot pattern according to an aspect of the present disclosure.

[0020] Figure 14 is an illustration of an example wireless network environment, which can be used in combination with the various systems and methods described here.

[0021] Figure 15 is an illustration of an example system that facilitates the construction of a pilot pattern in multiplexed multicast and multicast transmissions.

DETAILED DESCRIPTION

[0022] Various modalities are now described with reference to the drawings, where similar reference numerals are used to refer to similar elements from beginning to end. In the following description, for the sake of explanation, numerous specific details are set out to provide a complete understanding of one or more modalities. It may be evident, however, that such modality (s) can be put into practice without these specific details. In other instances, well-known structures and devices are shown in the form of a block diagram to facilitate the description of one or more modalities.

[0023] As used in this application, the terms "component", "module", "system", and the like are intended to refer to an entity related to computer, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a processor, a process running on a processor, a processor, an object, an executable, a flow of execution, a program and / or a computer. As an illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside in a process and / or flow of execution and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can run from a variety of computer-readable mechanisms having multiple data structures stored in them. Components can communicate via local and / or remote processes as per a signal having one or more data packets (for example, data from one component interacting with another component on a local, distributed system, and / or over a network such as the Internet with other systems using the signal).

[0024] In addition, several modalities are described here with respect to a mobile device. A mobile device can also be called a system, a subscriber unit, subscriber station, mobile station, mobile, remote station, remote terminal, access terminal, user terminal, terminal, wireless communication device, user agent, user device or user equipment (UE). A mobile device can be a cell phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop station (WLL), a personal digital assistant (PDA), a portable device having capacity wireless connection, computing device, or other processing device connected to a wireless modem. In addition, several modalities are described here with respect to a base station. A base station can be used to communicate with a mobile device (s) and can also be referred to as an access point, Node B, or some other terminology.

[0025] In addition, several aspects or features described here can be implemented as a method, equipment, or industrial product using standard programming and / or engineering techniques. The term "industrial product" as used is intended to encompass a computer program accessible from any computer-readable device, carrier or medium. For example, computer-readable mechanisms may include, but are not limited to, magnetic storage devices (eg hard disk, floppy disk, magnetic strips, etc.), optical discs (eg compact disk (CD), digital versatile disk (DVD) etc.), smart cards, and flash memory devices (for example, EPROM, card, joystick, key unit, etc.). In addition, the various storage mechanisms described here may represent one or more devices and / or other machine-readable mechanisms for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other mechanisms capable of storing, containing, and / or loading instruction (s) and / or data.

[0026] With reference now to figure 1, a wireless communication system 100 is illustrated according to the various modalities presented here. System 100 comprises a base station 102 that can include multiple groups of antennas. For example, one antenna group may include antennas 104 and 106, another group may comprise antennas 108 and 110, and an additional group may include antennas 112 and 114. Two antennas are illustrated for each antenna group; however, a greater or lesser number of antennas can be used for each group. Base station 102 may additionally include a transmitting and receiving current, each of which in turn comprises a plurality of components associated with the transmission and reception of signals (for example, processors, modulators, multiplexers, demodulators, demultiplexers , antennas, etc.), as will be recognized by a person skilled in the art.

[0027] Base station 102 can communicate with one or more mobile devices such as mobile device 116 and mobile device 122; however, it should be recognized that base station 102 can communicate substantially with any number of mobile devices similar to mobile devices 116 and 122. Mobile devices 116 and 122 can be, for example, cell phones, smart phones, laptops, portable communication devices, portable computing devices, satellite radios, global positioning systems, PDAs and / or any other device suitable for communication through the wireless communication system 100. As shown, mobile device 116 is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to mobile device 116 via a direct link 118 and receive information from mobile device 116 via a reverse link 120. In addition, mobile device 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to mobile device 122 via a direct link 124 and receive information from mobile device 122 via a reverse link 126 . In a frequency division duplex (FDD) system, direct link 118 may use a different frequency band than that used by reverse link 120, and direct link 124 may employ a different frequency band than that employed by the link reverse 126, for example. In addition, in a duplex time division (TDD) system, forward link 118 and reverse link 120 may use a common frequency band and forward link 124 and reverse link 126 may use a common frequency band.

[0028] The set of antennas and / or the area in which they are designated to communicate can be referred to as a sector of the base station 102. For example, multiple antennas can be designed to communicate with mobile devices in a sector of the covered areas through base station 102. In communication via direct links 118 and 124, the transmission antennas of the base station 102 can use beam formation to improve the signal / noise ratio of direct links 118 and 124 for mobile devices 116 and 122. Also, although base station 102 uses beamforming to transmit to mobile devices 116 and 122 randomly spread across an associated cover, mobile devices in neighboring cells may be subject to less interference compared to a base station that transmits through a single antenna for all your mobile devices.

[0029] According to an example, system 100 can be a multiple input multiple output (MIMO) communication system. In addition, system 100 can use any type of duplexing such as FDD, TDD, etc. In accordance with an illustration, base station 102 can transmit via direct links 118 and 124 to mobile devices 116 and 122. In addition, mobile devices 116 and 122 can estimate respective direct link or downlink channels and generate corresponding feedback that can be provided to base station 102 via reverse links or uplinks 120 and 126.

[0030] Now returning to figure 2, a Communication Equipment 200 for use in a wireless combination environment is illustrated. Communication equipment 200 can be a base station or a portion thereof. In addition, Communication Equipment 200 may be a mobile device or a portion thereof. Communication Equipment 200 can send and receive data transmission to and from other Communication Equipment, base stations, mobile devices, etc. For example, Communication Equipment 200 may include receiver and / or transmitter systems configured for communication in a wireless communication system. Communication equipment 200 may employ wireless communication techniques, but is not limited to OFDMA, CDMA, TDMA, FDMA and the like. Communication equipment 200 includes a transmission type detector 202 that determines a type of transmission to be employed. The broadcast can be a single frequency network (SFN) broadcast (for example, simulcast). In addition, the transmission may be a single-stream transmission. In addition, a single frequency multicast broadcast (MBSFN) network transmission can be employed. Additionally, a combination of broadcast, SFN and / or MBSFN transmissions can be used. For example, single-stream transmissions can be combined or multiplexed with SFN transmissions over the same transmission time interval. In other words, Communication Equipment 200 allows broadcast and SFN transmission to be multiplexed by time division. It should be recognized that additional modes of transmission in addition to those mentioned above can be used with aspects of the present disclosure.

[0031] Communication equipment 200 may include a prefix selector 204 that determines a cyclic prefix for a transmission. Many types of modulation, such as OFDM, can use a cyclic prefix in link building. In accordance with an illustration, the cyclic prefix facilitates improved reception of a transmission under multipath channel conditions. Multipath is a propagation effect in wireless communication that results in a radio signal arriving at antennas over two or more paths. Atmospheric channeling, reflection and / or refraction in the ionosphere, or reflection of buildings in mountains can create multipath channel conditions. The cyclic prefix can allow a multipath to settle before receiving effective transmission data. Typically, receiver systems decode a signal after settling to allow frequencies to achieve orthogonality. According to one aspect, the cyclic prefix can be a repeated portion of an OFDM or other mode symbol. For example, an extreme portion of a symbol can be repeated at the beginning of the symbol. In one embodiment, the length of the cyclic prefix is ​​equal to the protection period or interval.

[0032] Typically, the duration of the cyclic prefix should exceed the longest delay experienced on a multipath channel. Therefore, a variety of cyclic prefix lengths can be employed. The cyclic prefix can be a short cyclic prefix (for example, a duration of 4.7 microseconds), a long cyclic prefix (for example, 16.66 microseconds) or a larger cyclic prefix (for example, a duration of 33.33 microseconds). The larger cyclic prefix (for example, 33.33 microseconds) can be beneficial in SFN scenarios with extensive use of repeaters. The numerology for the larger cyclic prefix can be constructed by reducing the pitch pitch to 7.5 KHz.

[0033] Communication equipment 200 also includes a multiplexor 206 that can combine or multiplex two or more transmissions of different modes or types. In an illustrative instance, multiplexor 206 can multiplex point-to-point transmissions (e.g., unicast) with SFN or MBSFN transmissions. To minimize the loss of cyclic prefix insertion for single-stream, SFN and single-stream transmissions employing a larger cyclic prefix, it must be multiplexed by time division. In other words, certain partitions are dedicated to larger cyclic prefix SFN transmissions. However, to facilitate efficiency in RAN1, single-stranded and multichannel SFN multicast transmission reference symbols must be multiplexed in the same transmission time interval. In one embodiment, the multiplexor 206 alters resource allocation for partitions containing SFN broadcasts with cyclic prefix and single-stream transmissions. According to an illustration, the unicast reference symbols are transmitted in the first and third symbols of a partition. In addition, the frequency or tones allocated to the unicast reference symbols are staggered between the first and third symbols (for example, different frequencies are used in the third symbol than in the first symbol). Typically, unicast reference symbols occupy each sixth tone. According to one aspect of the present disclosure, multiplexor 206 structures the feature in such a way that single-reference reference symbols occupy each twelfth tone in the first and third symbols. The additional spread in the allocation maintains a critical sampling of the single-channel spread to facilitate accurate channel estimation for delay spreading up to 11 microseconds. In addition, by reducing the number of busy tones, the overhead of single-reference reference symbols in the frequency domain is also reduced. However, critical sampling is preserved due to the smaller pitch pitch of 7.5 KHz. The above metric is presented for illustrative purposes and not limitation. It should be recognized that other symbol spacing, frequency spacing, and scaling of single-reference reference symbols can be employed.

[0034] In addition, although not shown, it should be recognized that communications equipment 200 may include memory that retains instructions with respect to receiving packet data transmissions, combining packet data transmissions, decoding data transmissions, sending confirmation messages and the like. In addition, the memory can retain previously received data packets for combining before decoding. In addition, Communication Equipment 200 may include a processor that can be used with respect to execution instructions (for example, instructions retained in memory, instructions obtained from a different source, ...).

[0035] Now going back to figure 3, a wireless communication system 300 is illustrated, which employs multiplexed multicast and multicast transmissions. System 300 includes Communication Equipment 302 and 304. Communication Equipment 302 and / or 304 can be a base station or a portion thereof. In addition, Communication Equipment 302 and / or 304 may be a mobile device or a portion thereof. According to an illustration, system 300 can be used for wireless communication between one or more base stations, one or more mobile devices (for example, ad-hoc), or between base stations and mobile devices.

[0036] System 300 includes Communication Equipment 302 that communicates with Communication Equipment 304 (and / or any number of different equipment (not shown)). Communication equipment 302 can transmit data to equipment 304 through a direct link channel; o Equipment for additional communication 302 can receive data from equipment 304 through a reverse link channel. Direct link and reverse link channels can include point-to-point transmission modes (for example, unicast), point-to-multipoint transmission modes (for example, multicast) and / or diffusion transmission modes. In addition, system 300 can be a multiple input, multiple output (MIMO) system.

[0037] Communication equipment 302 includes a transmission type detector 306, a prefix selector 308 and a multiplexor 310. The transmission type detector 306 can determine the type or mode of transmission to be employed in a transmission to the equipment 304. For example, the transmission can be a single-stream transmission, an SFN transmission, an MBSFN transmission and / or a broadcast. The prefix selector 308 can determine a cyclic prefix for a transmission. In an illustrated instance, the cyclic prefix can be short, long, or longer. A short cyclic prefix can be 4.7 microseconds long, a long one can be 16.66 microseconds long and a longer or very long cyclic prefix can be 33.33 microseconds long. The determination can be based on channel conditions, desired overhead limits, transmission mode, etc.

[0038] Multiplexor 310 multiplexes symbols before transmission to equipment 304. Multiplexor 310 can multiplex reference symbols for unidiffusion and SFN transmission using a larger cyclic prefix in the same transmission time interval. In one illustrative instance, partitions containing larger cyclic prefix SFN transmissions and unicast transmissions can be structured by multiplexor 310 in such a way that unicast reference symbols are sent in the first and third symbols of the partition. In addition, frequency allocations for unicast reference symbols can be scaled between the first and third symbols. Additionally, the single-reference reference symbols can occupy every twelfth tone in the first and third symbols. Since the tone spacing is 7.5 KHz, the additional space between occupied tones reduces overhead without affecting critical sampling of the single channel. For partitions that do not contain SFN broadly prefixed transmissions, conventional techniques can be used.

[0039] Communication Equipment 304 may include a prefix detector 312 that determines the cyclic prefix duration employed by Communication Equipment 302 in a transmission or portion thereof. According to an illustration, Communication Equipment 304 may be a mobile device. Typically, a mobile device detects the cyclic prefix duration during an initial cell search procedure. Conventionally, mobile devices had two hypotheses: short cyclic prefix and long cyclic prefix. However, with the introduction of a larger cyclic prefix (for example 33.33 microseconds), a third hypothesis arises. In a transmission that employs larger cyclic prefix numerology, there are three symbols per partition. In a time division multiplexed (TDM) structure for primary synchronization codes (PSC) and secondary synchronization codes (SSC) are transmitted in two separate symbols in a partition. In this way, only one symbol per partition remains for transmission from the common control channel (CCCH) or primary diffusion channel (BCH). Consequently, in a modality, the numeric of larger cyclic prefix is ​​not used in partitions that contain PSC and / or SSC transmissions.

[0040] With reference now to figures 4-10, exemplary resource mappings are represented according to one aspect of the present disclosure. For the sake of simplicity of explanation, the examples illustrate a resource block in the dimensions of frequency and time that is equal in duration to a subframe or two partitions of a transmission (for example, 1 millisecond). Each block along the geometric frequency axis represents a tone where the spacing between tones depends on the duration of the cyclic prefix used. Each block along the geometric time axis represents a symbol where the duration and number of symbols also depend on the cyclic prefix used. It should be recognized that figures 4-10 are for illustrative purposes and that the material disclosed is not limited to the scope of these examples. Those skilled in the art should recognize how resource mappings can be extended to systems that include a different number of antennas, variable pitch spacing, subframe duration, etc.

[0041] In one embodiment, the conventional reference symbol structure is identical for long cyclic prefix duration (for example, 16.66 microseconds) and short cyclic prefix duration (for example, 4.7 microseconds). Using the conventional structure, the channel estimation performed by any mobile device can be aliased if the delay spread (for example, time difference between a first multipath component and a last multipath component) is greater than 13 microseconds. Even with long cyclic prefix duration or longer cyclic prefix duration, numerology cannot be used if single-spread delay spreading exceeds a limit. Figures 4 and 5 represent two unidifusion pilot structures employed with long cyclic prefix duration transmissions that facilitate avoiding the mismatch between prefix duration and channel estimation accuracy.

[0042] In figure 4, a subframe (two partitions) containing unidiffusion pilot symbols is illustrated. Under a long cyclic prefix duration, each partition contains six symbols. The represented structure provides efficient operation in high Doppler scenarios. Pilot symbols are transmitted on the first and fourth symbols of the first partition as well as the first and fourth symbols of the second partition. In the fourth symbols of the two partitions, not all resources are mapped to antennas. In addition, mappings are shifted to provide diversity. Figure 5 represents another pilot pattern that provides lower overhead. This structure illustrates pilot symbols that occupy alternating tones in the first and fourth symbols of the two partitions. This structure reduces overhead in half. Similar to the pattern shown in figure 4, the mappings are shifted to provide diversity.

[0043] Figures 6 and 7 represent multiplexed unicast transmissions and MBSFN according to one aspect of the present disclosure. In an illustrative instance, the examples represented involve single-stream transmissions on the confirmation channel (ACKCH) and the physical downlink control channel (PDCCH). No single-stream data is transmitted. In one embodiment, the PDCCH and ACKCH transmission covers two OFDM symbols. Figure 6 represents multiplexed transmissions based on a pilot pattern similar to that represented in figure 4 whereas figure 7 represents multiplexed transmission based on a pilot pattern similar to that illustrated in figure 5.

[0044] In the illustrated multiplexed resource blocks, unidiffusion reference symbols are shown mapped to specific antennas. In this exemplary scenario, a 4-antenna MIMO system is provided. In addition to the unicast reference symbols, PDCCH and ACKCH unicast transmissions are sent in the first two symbols of the subframe. In addition, SFN data and SFN reference symbols are also sent as symbols in the represented subframe. In figure 6, the structure of single-reference reference symbols is not changed; however overhead remains large. In figure 7, unicast reference symbols are not sent on the second partition of the subframe. Without unidiffusion data, the multiplexed structures in figures 6 and 7 facilitate the reduction of overhead. The accuracy of the channel quality indicator (CQI) is impacted as well as any coherent demodulation in subframes subsequent to the illustrated example.

[0045] Now returning to figures 9 and 10, single-reference reference symbol patterns are illustrated for a single-diffusion pilot structure that employs a longer cyclic prefix duration. For example, the length of the longest cyclic prefix can be 33.33 microseconds and is built by reducing a pitch pitch from 15 KHz to 7.5 KHz. Under the longer cyclic prefix duration, each partition contains 3 symbols as opposed to six. Therefore, a 1 millisecond subframe contains 6 symbols instead of 12. The pattern shown in figure 9 can be used with 4 flow MIMO systems. The pattern shown in figure 10 provides lower overhead in systems that employ 2-stream MIMO with cyclic delay diversity (CDD) from other physical antennas, if available.

[0046] Referring now to Figure 8, a single-spread reference symbol pattern for a multiplexed single-stream transmission with a larger cyclic prefix SFN transmission is illustrated in accordance with an aspect of the present disclosure. Similar to figures 6 and 7, the exemplary subframe illustrated in figure 8 contains unicast reference symbols, SFN reference symbols, PDCCH transmission and ACKCH unicast and SFN data. On partitions containing larger cyclic prefix and single-stream SFN transmissions, the resulting spacing is 7.5 KHz and each partition contains 3 symbols. Unicast reference symbols are sent on the first symbol of the partition. In addition, the frequency is scaled between the reference symbols in the first symbol of the first partition and the first symbol of the second partition in the 1 millisecond subframe. Although scaling is represented as six tones in magnitude, it must be recognized that other amounts of scaling can be used. In addition, the unicast reference symbols occupy every twelfth tone of the first symbol of each partition. For example, antenna 1 can be mapped to a reference symbol in a specific tone. The next mapping of antenna 1 is twelve tones higher or lower than the specific tone. The scattering of reference symbols for each twelfth tone maintains critical sampling of the unidifusion channel for delayed scatters that approach eleven microseconds while also reducing overhead in the frequency domain. For partitions that do not contain SFN transmissions with a longer cyclic frequency, the tone spacing can be 15 KHz and a nominal structure like the one illustrated in figures 6 and 7 can be used.

[0047] With reference to figure 11, a methodology is illustrated that refers to the facilitation of SFN transmission multiplexing and unidiffusion while preserving the unidiffusion pilot structure with sufficient critical sampling properties. Although for the sake of simplicity of explanation, the methodology is shown and described as a series of acts, it must be understood and recognized that the methodology is not limited by the order of acts, since some acts may, according to one or more modalities, occur in different orders and / or simultaneously with other acts in relation to that shown and described here. For example, those skilled in the art will understand and recognize that a methodology could alternatively be represented as a series of interrelated states or events, as in a state diagram. In addition, not all illustrated acts may be necessary to implement a methodology according to one or more modalities.

[0048] Turning now to Figure 11, an 1100 methodology is illustrated that facilitates the provision of a pilot structure in multiplexed unidifusion transmission with SFN transmissions with longer cyclic prefix durations. The 1100 method can be used, among other things, to build a pilot pattern in a multiplexed situation that offers sufficient critical sampling for channel estimation while reducing overhead. In one embodiment, the 1100 method can be implemented on a mobile device and / or a base station in a wireless communication system. In reference numeral 1102, a type of transmission is observed. The transmission can be a single-stream transmission, an SFN transmission, an MBSFN transmission, a broadcast transmission, etc. In addition, the transmission can be any combination of them. In addition, the transmission may include variable lengths of cyclic prefix. For example, the cyclic prefix duration can be short (for example, 4.7 microseconds), long (16.66 microseconds) or longer (33.33 microseconds). At reference numeral 1104, a determination is made as to whether the transmission includes partitions with SFN transmission that employ a long or longer cyclic prefix duration. If negative, method 1100 proceeds to reference numeral 1106 where the conventional reference symbol structure is used. If an SFN transmission with a larger cyclic prefix is ​​present, method 1100 proceeds to reference numeral 1108. In 1108, a structure is created where unicast reference symbols are sent in the partition symbol. In reference numeral 1110, the space between tones occupied by the unidiffusion reference symbols of the first partition symbol is increased. For example, reference symbols can be spaced to occupy each twelfth tone of the first symbol and broader cyclic prefix transmissions as opposed to each sixth tone typically used in long and / or short cyclic prefix transmissions. In reference numeral 1112, the frequency is scaled between the first symbol of a partition containing unicast reference symbols and the first symbol of a subsequent partition containing unicast reference symbols. When the two partitions are comprised in the same subframe, the frequency is spread between the first and fourth symbols in the subframe.

[0049] It will be recognized that according to one or more aspects described here, inferences can be made regarding which mode of transmission is employed, which cyclic prefix duration is used, whether a special multiplexed pattern should be employed, etc. As used here, the term "infer" or "inference" refers generally to the process of reasoning about or inferring states of the system, environment and / or user from a set of observations as captured through events and / or data. Inference can be used to identify a specific context or action, or it can generate a probability distribution over states, for example. The inference can be probabilistic - that is, the computation of a probability distribution across states of interest based on a consideration of data and events. Inference can also refer to techniques used to compose higher level events from a set of events and / or data. Such inference results in the construction of new events or actions from a set of observed events and / or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or various data sources and events.

[0050] According to an example, one or more of the methods presented above may include making inferences pertinent to determining the mode of transmission. As an additional illustration, an inference can be made regarding the determination of whether a partition contains larger cyclic prefix SFN transmissions and unidiffusion transmission, whether a high Doppler structure should be employed, whether overhead reduction should be the main objective, etc. It will be recognized that the examples above are of an illustrative nature and are not intended to limit the number of inferences that can be made or the way in which such inferences are made in combination with the various modalities and / or methods described here.

[0051] Figure 12 is an illustration of a mobile device 1200 that facilitates the use of transmission containing SFN transmission and multiplexed unicast with lengths of greater cyclic prefix. User device 1200 comprises a receiver 1202 that receives a signal from, for example, a receiving antenna (not shown), and performs typical actions on it (for example, filters, amplifies, downwards converts, etc.) received signal and digitizes the conditioned signal to obtain samples. The receiver 1202 can be, for example, an MMSE receiver, and can comprise a demodulator 1204 that can demodulate received symbols and provide them to a processor 1206 for channel estimation and the like. Processor 1206 can be a processor dedicated to analyzing information received by receiver 1202 and / or generating information for transmission by a transmitter 1216, a processor that controls one or more user device components 1200, and / or a processor that both analyzes information received by receiver 1202, generates information for transmission by transmitter 1216, and controls one or more user device components 1200.

[0052] The mobile device 1200 may additionally comprise memory 1208 which is operatively coupled to the processor 1206 and which can store data to be transmitted, data received, information related to available channels, data associated with the analyzed signal and / or intensity of interference , information related to an assigned channel, power, rate or the like, and any other information appropriate for estimating a channel and communicating through the channel. Memory 1208 can additionally store protocols and / or algorithms associated with estimating and / or using a channel (e.g., performance-based, capacity-based, etc.).

[0053] It will be recognized that the data storage (for example, memory 1208) described here may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. As an illustration, and not a limitation, non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable PROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM), which acts as an external cache memory. As an illustration and not a limitation, RAM is available in many forms such as synchronous RAM (SCRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), DRAM Synchlink (SLDRAM) and RAM Rambus Direct (DRRAM). The memory 1208 of the present systems and methods is intended to be understood, without being limited to these and any other appropriate types of memory.

[0054] Processor 1202 is additionally operatively coupled to a prefix detector 1210 that determines the cyclic prefix duration used by the Communication Equipment 302 in a transmission or portion thereof. According to an illustration, Communication Equipment 304 may be a mobile device. Typically, a mobile device detects the cyclic prefix duration during an initial cell search procedure. Conventionally, mobile devices had two hypotheses: short cyclic prefix and long cyclic prefix. However, with the introduction of a larger cyclic prefix (for example, 33.33 microseconds), a third hypothesis emerges. In a transmission that employs larger cyclic prefix numerology, there are three symbols per partition. After detecting the cyclic prefix numerology used, the transmission can be decoded and the reference symbols used for single channel estimation. The mobile device 1200 further comprises a modulator 1214 and a transmitter 1216 that transmits a signal (e.g., confirmation message) to, e.g., a base station, another mobile device, etc. Although represented as being separate from processor 1206, it should be recognized that prefix detector 1210 and / or modulator 1214 may be part of processor 1206 or a number of processors (not shown).

[0055] Figure 13 is an illustration of a 1300 system according to one aspect of the present disclosure. The system 1300 comprises a base station 1302 (e.g., access point, ...) with a receiver 1310 that receives signal (s) from one or more mobile devices 1304 through a plurality of receiving antennas 1306, and a transmitter 1322 which transmits to one or more mobile devices 1304 through a plurality of transmission antennas 1308. In one aspect, transmitter 1322 can transmit a data stream to one or more mobile devices 1304 as a sequence of data packets in such a way that each packet is transmitted, in turn, until confirmed. The receiver 1310 can receive information from receiving antennas 1306 and is operatively associated with a demodulator 1312 that demodulates received information. Demodulated symbols are analyzed by a processor 1314 that can be similar to the processor described above with respect to figure 12, and that is coupled to a memory 1316 that stores information related to the estimation of a signal strength (for example, pilot) and / or intensity of interference, data to be transmitted to or received from 1304 mobile device (s) (or a different base station (not shown)), and / or any other appropriate information related to the execution of the various actions and functions exposed here.

[0056] The processor 1314 can be additionally coupled to a transmission detector 1318 which determines the transmission mode to be employed in a transmission to mobile devices 1304. The transmission mode can be one between a single-mode, an SFN mode, a MBSFN mode, a broadcast mode or a combination thereof. Base station 1302 may further include a prefix selector 1320 that selects a cyclic prefix duration to employ in the transmission or a portion thereof. For example, variable durations of cyclic prefix can be used in different subframes of a transmission. Information to be transmitted can be provided to a modulator. Modulator 1322 can multiplex information for transmission by a transmitter 1326 through antennas 1308 to mobile device (s) 1304. Although represented as being separated from processor 1314, it should be recognized that demodulator 1312, detector 1318, selector 1320 and / or modulator 1322 may be part of processor 1314 or a number of processors (not shown).

[0057] Figure 14 shows an example wireless communication system, 1400. The wireless communication system 1400 represents a base station 1410 and a mobile device 1450 for the sake of brevity. However, it should be recognized that the 1400 system may include more than one base station and / or more than one mobile device, where additional base stations and / or mobile devices may be substantially similar to or different from the example base station 1410 and mobile device 1450 described below. In addition, it should be recognized that the base station 1410 and / or mobile device 1450 can employ the systems (figures 1-3 and 12-13) and / or methods (figure 11) described here to facilitate wireless communication between them.

[0058] At base station 1410, traffic data for a number of data streams is provided from a data source 1412 to a transmission data processor (TX) 1414. According to an example, each data stream can be transmitted via a respective antenna. The TX 1414 data processor formats, encodes, and merges the traffic data stream based on a specific coding scheme selected for that data stream to provide encrypted data.

[0059] The encoded data for each data stream can be multiplexed with pilot data using orthogonal frequency division (OFDM) multiplexing techniques. Additionally or alternatively, the pilot symbols can be multiplexed by frequency division (FDM), multiplexed by time division (TDM), or multiplexed by code division (CDM). Pilot data is typically a known data pattern that is processed in a known manner and can be used on the mobile device 1450 to estimate channel response. The multiplexed encoded and pilot data for each data stream can be modulated (for example, mapped in symbols) based on a specific modulation scheme (for example, binary phase switching (BPSK) manipulation, phase switching manipulation quadrature (QPSK), M-phase switching manipulation (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected for that data stream to provide modulation symbols. The data rate, encoding and modulation for each data stream can be determined by instructions executed or provided by the 1430 processor.

[0060] The modulation symbols for the data streams can be provided for a MIMO TX 1420 processor, which can additionally process the modulation symbols (for example, for OFDM). The MIMO TX 1420 processor then provides NT modulation symbol streams for NT transmitters (TMTR) 1422a through 1422t. In various modalities, the MIMO TX 1420 processor applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

[0061] Each transmitter 1422 receives and processes a respective symbol stream to provide one or more or more analog signals, and further conditions (for example, amplifies, filters and converts upwards) the analog signals to provide a suitable modulated signal for transmission over the MIMO channel. In addition, NT modulated signals from transmitters 1422a through 1422t are transmitted from NT antennas 1424a through 1424t, respectively.

[0062] In the mobile device 1450, the transmitted modulated signals are received by antennas NR 1452a through 1452r and the signal received from each antenna 1452 is supplied to a respective receiver (RCVR) 1454a through 1454r. Each 1454 receiver conditions (e.g., filters, amplifies, and downwardly converts) a respective signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

[0063] An RX 1460 data processor can receive and process the received Nr symbol streams from Nr 1454 receivers based on a specific receiver processing technique to provide "detected" Nt symbol streams. The RX 1460 data processor can demodulate, deinterleave and decode each detected symbol stream to retrieve traffic data for the data stream. Processing by the RX 1460 data processor is complementary to that performed by the MIMO TX 1420 processor and TX 1414 data processor at the base station 1410.

[0064] A 1470 processor can periodically determine which pre-coding matrix to use as discussed above. In addition, processor 1470 can formulate a reverse link message comprising a matrix index portion and a rating value portion.

[0065] The reverse link message can comprise various types of information regarding the communication link and / or data flow received. The reverse link message can be processed by a TX 1438 data processor, which also receives traffic data for a number of data streams from a data source 1436, modulated by a modulator 1480, conditioned by transmitters 1454a through 1454r , and transmitted back to base station 1410.

[0066] At base station 1410, signals modulated from mobile device 1450 are received by antennas 1424, conditioned by receivers 1422, demodulated by a demodulator 1440, and processed by an RX 1442 data processor to extract the reverse link message transmitted by mobile device 1450. In addition, processor 1430 can process the extracted message to determine which pre-coding matrix to use to determine the beam formation weights.

[0067] Processors 1430 and 1470 can direct (for example, control, coordinate, manage, etc.) operation on base station 1410 and mobile device 1450, respectively. The respective processors 1430 and 1470 can be associated with memory 1432 and 1472 which store program codes and data. Processors 1430 and 1470 can also perform computations to derive pulse and frequency response estimates for the uplink and downlink, respectively.

[0068] It should be understood that the modalities described here can be implemented in hardware, software, firmware, middleware, microcode or any combination thereof. For a hardware implementation, processing units can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPS), digital signal processing devices (DSPDs), programmable logic devices (PLDs) ), field programmable port arrangements (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described here, or a combination thereof.

[0069] When the modalities are implemented in software, firmware, middleware or microcode, program code or code segments, they can be stored in a machine-readable medium, as a storage component. A code segment can represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or statements of program. A code segment can be coupled to another code segment or a hardwire circuit passing and / or receiving information, data, arguments, parameters, or memory content. Information, arguments, parameters, data, etc., can be passed, sent, or transmitted using any appropriate means including sharing memory, message passing, token passing, network transmission, etc.

[0070] For a software implementation, the techniques described here can be implemented with modules (for example, procedures, functions and so on) that perform the functions described here. Software codes can be stored in memory units and executed by processors. The memory unit can be implemented in the processor or external to the processor, in which case it can be communicatively coupled to the processor through various means as known in the art.

[0071] With reference to figure 15, a system 1500 is illustrated that transmits multiplexed pilot signals with multicast transmissions. For example, the 1500 system can reside at least partially on a mobile device and / or base station. It should be recognized that the 1500 system is represented as including function blocks, which can be function blocks that represent functions implemented by a processor, software, or combination thereof (for example, firmware). System 1500 includes a logical grouping 1502 of electrical components that can act in combination. For example, logical grouping 1502 can include an electrical component to classify a transmission mode 1504. The mode can be a point-to-point transmission (for example, unicast), a point-to-multipoint transmission (for example, multicast), a dissemination or a combination thereof. In addition, logical grouping 1502 may comprise an electrical component for selecting a cyclic prefix duration 1506. For example, the mode of transmission, channel conditions or efficiency concerns may influence the cyclic prefix duration used. In addition, logical grouping 1502 can include an electrical component to multiplex pilot information into a subframe 1506. For example, in a subframe containing larger cyclic prefix SFN transmissions, unidiffusion pilot information can be sent on the first and fourth symbols of the subframe. In addition, the frequency used can be spread between the first and fourth symbols. In addition, the 1500 system may include a 1510 memory that holds instructions for performing functions associated with electrical components 1504, 1506 and 1508. Although shown to be external to memory 1510, it should be understood that one or more of the electrical components 1504, 1506 and 1508 may exist within memory 1510.

[0072] What has been described above includes examples of one or more modalities. It is, of course, not possible to describe every conceivable combination of components or methodologies for the purpose of describing the aforementioned modalities, but a person of ordinary skill in the art may recognize that many additional combinations and permutations of various modalities are possible. Therefore, the modalities described are intended to cover all such changes, modifications and variations that are included in the spirit and scope of the attached claims. In addition, to the extent that the term "includes" is used in the detailed description or claims, it is intended to be inclusive in a similar way to the term "comprising" as "comprising" is interpreted when used as a transitional word in a claim.

CLAIMS