TWI390935B - Enhancements to the positioning pilot channel - Google Patents

Description

Promotion of positioning pilot channels

The present application relates generally to the operation of a communication system and, more particularly, to a method and apparatus for transmitting identification information about a transmitter in a communication system.

This patent application claims Provisional Application No. 61/030,178, filed on February 20, 2008, and Provisional Application No. 61/023,919, filed on January 28, 2008, and filed on January 28, 2008 The priority of Provisional Application No. 61/024, 143, the disclosure of which is hereby incorporated by reference in its entirety in its entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire disclosure

In currently known communication systems, such as content delivery/media decentralized systems (eg, forward link only (FLO) or digital video broadcast (DVB-T/H) systems), instant and non-instant services are typically packaged to Transmission frames (eg, FLO hyperframes) and delivered to devices on the network. Additionally, such communication systems may utilize orthogonal frequency division multiplexing (OFDM) to provide a network server and one or more mobile devices Inter-communication. This communication provides a transmission hyperframe with data slots that are packaged with content that will be delivered as a transmission waveform over a decentralized network.

It is known to perform transmitter identification and position determination for mobile devices in some wireless networks via the use of Positioning Pilot Channels (PPC) in the FLO network. In particular, known transmitter identification involves determining a channel profile based on the pilot symbols of the PPC symbols in each of the individual transmitters to a receiver. Although the transmitter identification code may not be explicitly encoded in the PPC symbol, as long as it knows when the transmitter transmits the schedule of the active PPC symbols, it can determine the identity of the transmitter in a given area, such as multiple times with pseudo-time division. The access (TDMA) mode sorts the active transmitters (e.g., the transmitter follows a known time sequence of transmissions in effect for only one transmitter at a time in the given area). Therefore, it is possible to map the transmitter to the corresponding PPC symbol using the position of the active PPC symbol in a superframe, but additionally use the additional channel in the superframe (for example, the additional information symbol (OIS) ). Under this scheme, the periodicity (ie, scheduling) of the network transmitter in the hyperframe must also be known by the receiver.

According to one aspect, a method for communicating transmitter identification in a communication system is disclosed. The method includes encoding pilot information on a first portion of a plurality of subcarriers in a symbol of an active transmitter, and encoding transmitter identification information on a second portion of the plurality of subcarriers of the symbol.

According to another aspect, an apparatus for communicating transmitter identification information in a network is disclosed. The apparatus includes: a first module configured to encode pilot information on a first portion of a plurality of subcarriers in a symbol of an active transmitter; and a second module configured to Transmitter identification information is encoded on a second portion of the plurality of subcarriers of the symbol.

According to yet another aspect, another apparatus for transmitting transmitter identification information in a communication system is disclosed. The apparatus is characterized by means for encoding pilot information on a first portion of a plurality of subcarriers in a symbol of an active transmitter, and for encoding on a second portion of the plurality of subcarriers of the symbol The component of the transmitter that identifies the information.

According to yet another aspect, a computer program product is disclosed. The computer program product includes a computer readable medium having code for encoding pilot information on a first portion of a plurality of subcarriers in a symbol of an active transmitter, and And causing a computer to encode the code of the transmitter identification information on the second portion of the plurality of subcarriers of the symbol.

In another aspect, at least one processor is disclosed, the at least one processor configured to perform a method for transmitting transmitter identification information in a network. The method includes encoding pilot information on a first portion of a plurality of subcarriers in a symbol of an active transmitter, and encoding transmitter identification information on a second portion of the plurality of subcarriers of the symbol.

In yet another aspect, a method for determining transmitter identification information in a device in a communication system is disclosed. The method includes receiving at least one symbol having a plurality of subcarriers from a transmitter. The method further includes determining a channel estimate and an energy measurement of the at least one symbol using the first portion of the plurality of subcarriers of the at least one symbol, and decoding one of the plurality of subcarriers in the at least one symbol The second part is dedicated to determine the transmitter identification information.

According to still another aspect, an apparatus for determining transmitter identification information in a device in a communication system is disclosed. The apparatus includes means for receiving at least one symbol having a plurality of subcarriers from a transmitter, and for determining a channel estimate of the at least one symbol using a first portion of the plurality of subcarriers in the at least one symbol And an energy measuring component. The apparatus further includes means for decoding a dedicated second portion of the plurality of subcarriers of the at least one symbol to determine the transmitter identification information.

In yet another aspect, a computer program product is disclosed. The computer program product is characterized by a computer readable medium having code for causing a computer to receive at least one symbol having a plurality of subcarriers from a transmitter, and for causing a computer to use the at least one symbol The first portion of the plurality of subcarriers determines a channel estimate of the at least one symbol and an energy measurement code. The medium also includes code for causing a computer to decode a dedicated second portion of the plurality of subcarriers in the at least one symbol to determine the transmitter identification information.

In yet another aspect, it is assumed that the signal is transmitted in the form of a transmitter location coordinate (e.g., GPS location coordinates), and a novel embodiment for presenting and transmitting the transmitter location information is presented herein.

The present disclosure relates to a method and apparatus for transmitting identification information about a transmitter in a communication system. The methods and apparatus provide a solution for transmitter identification and location determination using a PPC channel that does not require that the schedule of the transmitters in the LAN area be known to the receiver. In particular, the disclosed method and apparatus use PPC symbols including transmitter identification information such that the receiver only needs timing information from a hyperframe and the PPC symbol to determine the identification code of the active transmitter. In a particular example, the transmitter identification code can be explicitly encoded in the PPC symbols. By explicitly encoding the transmitter identification code in the PPC symbols, there is no need to know the higher order scheduling information of the network transmitter at the transmitter. However, the transmitter will have to perform additional processing to embed the transmitter identification code information in the PPC symbols in a robust manner, and the receiver will have to process the PPC symbols to extract the transmitter identification code information. However, the transmitter identification information supply receiver identifies the transmitter and the less processing resources needed to use the corresponding channel location of the identified transmitter's channel profile. Additionally, additional information encoded with the identification can be signaled to the receiver regardless of whether a particular transmitter is using other symbols.

For the purposes of this description, reference is made herein to a communication network (such as FLO or DVB-T/H) that utilizes orthogonal frequency division multiplexing (OFDM) to provide communication between a network transmitter and one or more mobile devices. ) to describe the transmitter identification scheme. In one example, the disclosed communication system may use the concept of a single frequency network (SFN) in which signals from multiple transmitters in the network carry the same content and transmit the same waveform. As a result, the waveforms can be considered by the receiver to be signals from the same source but with different propagation delays.

Additionally, it should be noted that the exemplary OFDM systems disclosed herein may, for example, utilize hyperframes. The hyperframes include data symbols for transporting services from the server to the receiving device. According to an example, a data slot can be defined as a predetermined number of data symbols (e.g., 500) occurring within an OFDM symbol time. In addition, one of the OFDM symbol times in the superframe can carry eight data slots (for example only).

According to another example, one of the PPCs in a hyperframe includes PPC symbols for providing transmitter identification information for channel estimates for individual transmitters in the network to be determined. These individual channel estimates can then be used for network optimization (transmitter delay for network optimization and power profile measurement) and position location (via measurement of delays from all nearby transmitters, followed by triangulation) Testing technology).

In an exemplary system, the hyperframe boundaries at all transmitters can be synchronized to a common clock reference. For example, the common clock reference can be obtained from a Global Positioning System (GPS) time reference. A receiving device can then use the PPC symbols to identify a particular transmitter and channel estimates from a group of transmitters in the vicinity of the receiving device.

1 illustrates a communication network 100 in which the presently disclosed methods and apparatus can be used. The illustrated network 100 includes two wide area areas 102 and 104. Each of the wide area regions 102 and 104 typically covers a large geographic area, such as a state, multiple states, a portion of a country, an entire country, or more than one country. Also, the wide area 102 or 104 may include a local area (or sub-area). For example, wide area area 102 includes local area areas 106 and 108, and wide area area 104 includes local area area 110. It should be noted that network 100 illustrates only one network configuration and may cover other network configurations with any number of wide and local areas.

Each of the local area 106, 108, 110 includes one or more transmitters that provide network coverage for mobile devices (e.g., receivers). For example, region 108 includes transmitters 112, 114, and 116 that provide network communications to mobile devices 118 and 120. Similarly, region 106 includes transmitters 122, 124, and 126 that provide network communications to devices 128 and 130, and region 110 is shown as transmitters 132, 134, and 136 that provide network communications to devices 138 and 140.

As illustrated in Figure 1, a receiving device may receive PPC symbols from a transmitter within its local area, from a transmitter in another local area within the same wide area, or from a transmitter in a local area outside its wide area. Hyperframe transmission. For example, as illustrated by arrows 142 and 144, device 118 may receive a hyperframe from a transmitter within its local area 108. As illustrated by arrow 146, device 118 may also receive a hyperframe from a transmitter in another local area 106 within wide area 102. As illustrated at 148, device 118 potentially further receives a hyperframe from a transmitter in local area 110, which is in another wide area 104.

The disclosure of U.S. Patent Application Serial No. 11/517,119, the entire disclosure of which is hereby incorporated by reference in its entirety in its entirety in The PPC symbols transmitted by the active transmitter are configured differently such that their transmitters are idle or inactive while being transmitted relative to the PPC symbols. During operation, each transmitter uses network provisioning information to determine which transmitter in an area will be the "active transmitter."

For the purposes of this application, it should be noted that the active transmitter is a transmitter that transmits a PPC symbol that includes identification information that uses at least a portion (eg, an interlace) of the subcarriers. Although only one active symbol is assigned to the active transmitter, it is possible to assign any number of active symbols to a transmitter. Thus, each transmitter is associated with an "active symbol" by which the transmitter transmits information including the identification information. When the transmitter is not in an active state, it is transmitted on a defined idle portion (e.g., interlace) of the PPC symbol. The receiving devices in the network can then be configured to not "listen" for information in the idle portion of the PPC symbols. This allows the transmitter to transmit during the idle portion of the PPC symbols to provide power (i.e., energy per symbol) stability to maintain network performance. In another example, the symbols transmitted on the PPC are designed to have a long cycle first code (CP) such that the receiving device can utilize information from the remote transmitter for location determination purposes. This mechanism allows the receiving device to receive identification information from the particular transmitter during the associated symbol in the particular transmitter without interference from other transmitters in the area, since other transmitters are idle in the symbol. Partial (interlaced) transmission.

2 shows an example of a communication system 200 that includes transmission of transmitter identification information (referred to herein as TxID). System 200 includes a plurality of transmitters (e.g., five transmitters T1 through T5) that transmit a hyperframe including pilot positioning channel (PPC) 202 to at least one receiving device 206 via wireless link 204. Transmitters T1-T5 may represent their transmitters in the vicinity of device 206 and may include transmitters within the same local area as device 206, transmitters in different local areas, or transmitters in different wide areas. It should be noted that the transmitters T1-T5 may be part of a communication network that is synchronized to a single time reference (e.g., GPS time) such that the hyperframes transmitted from the transmitters T1-T5 are aligned and synchronized in time. It should be noted that it may be possible to allow the start of the hyperframe to have a fixed offset relative to the single time reference and to account for the offset of the respective transmitters in the determination of the propagation delay. Therefore, the content of the transmitted hyperframe can be the same for transmitters in the same local area, but can be different for transmitters in different local or wide areas, however, since the network is synchronized Thus, the hyperframes are aligned, and the device 206 can receive symbols from nearby transmitters via the PPC 202, and the symbols are also aligned.

As illustrated by the exemplary transmitter block 214, each of the transmitters T1-T5 can include transmitter logic 208, PPC generator logic 210, and network logic 212. As illustrated by the exemplary receiving device 222, the receiving device 206 can include receiver logic 216, PPC decoder logic 218, and transmitter ID decision logic 220.

It should be noted that the transmitter logic 208 can comprise hardware, software, firmware, or any suitable combination thereof. Transmitter logic 208 is operable to transmit audio, video, and network services using a transmission hyperframe. Transmitter logic 208 is also operative to transmit one or more PPC symbols in a superframe. In one example, transmitter logic 208 transmits one or more PPC symbols 234 in a hyperframe via PPC 202 to provide transmitter identification information for use by receiving device 222 to identify a particular transmitter and for Achieve other purposes such as positioning.

PPC generator logic 210 includes hardware, software, or any combination thereof. PPC generator logic 210 operates to incorporate transmitter identification information into symbols 234 transmitted via PPC 202. In one example, each PPC symbol comprises a plurality of subcarriers grouped into a selected number of interlaces. An interlace can be defined as a collection or collection of uniformly spaced subcarriers across the available frequency bands. It should be noted that the interleaving may also consist of a group of subcarriers that are not uniformly spaced apart.

In an example, each of the transmitters T1-T5 is assigned at least one PPC symbol, which is referred to as the active symbol of the transmitter. For example, the transmitter T1 is assigned a PPC symbol 236 in the PPC symbol 234 in the superframe and the transmitter T5 is assigned a PPC symbol 238 in the PPC symbol 234 in the superframe.

The PPC generator logic 210 operates to encode the transmitter identification information into the active symbols of the transmitter. For example, the interlace of each symbol is grouped into two groups called "interactive interleaving" and "idle interleaving". The PPC generator logic 210 operates to interleave the encoded transmitter identification information in a dedicated role of the symbols in the role of the transmitter. For example, the transmitter T1 identification information is transmitted interleaved in the role of the symbol 236, and the transmitter T5 identification information is interleaved for transmission in the dedicated role of the symbol 238. When a transmitter does not transmit its identification on the active symbol, PPC generator logic 210 operates to encode idle information on the idle interlaces of the remaining symbols. For example, if PPC 202 contains ten symbols, then in the SFN network, up to ten transmitters will each be assigned a PPC symbol as their respective active symbol. Each transmitter will interleave the identification information in the role of its respective active symbols and will encode the idle information on the idle interlaces of the remaining symbols. It should be noted that when a transmitter transmits idle information on an idle interlace of a PPC symbol, the transmitter logic 212 operates to adjust the power of the transmitted symbol to maintain a constant energy power level per symbol.

Network logic 212 can be configured by hardware, software, firmware, or any combination thereof. Network logic 212 is operable to receive network provisioning information 224 and system time 226 for use by the system. The supply information 224 is used to determine an active symbol for each of the transmitters T1-T5 during which each transmitter will interleave the identification information in the role of its active symbol. System time 226 is used to synchronize the transmissions so that the receiving device can determine the channel estimates for a particular transmitter, as well as the auxiliary propagation delay measurements.

Receiver logic 218 includes hardware, software, or any combination thereof. Receiver logic 218 operates to receive transmission hyperframes and PPC symbols 234 from nearby transmitters on PPC 202. Receiver logic 218 operates to receive PPC symbols 234 and pass them to PPC decoder logic 220.

PPC decoder logic 220 includes hardware, software, or any combination thereof. PPC decoder logic 220 operates to decode PPC symbols to determine an identification code for a particular transmitter associated with each symbol. For example, decoding logic 220 operates to decode the interleaving of each received PPC symbol to determine the identification code of the particular transmitter associated with the symbol. Once the transmitter identification code is determined, the PPC decoder logic 220 operates to determine the channel estimate for the transmitter. For example, using the time reference associated with the received hyperframe, PPC decoder logic 220 can determine a channel estimate for the active transmitter associated with each received PPC symbol. Accordingly, PPC decoder logic 220 operates to determine a plurality of transmitter identifiers and associated channel estimates. This information is then passed to location decision logic 221.

The location decision logic 221 includes hardware, software, or any combination thereof. The location decision logic 221 operates to calculate the location of the device 206 based on the decoded transmitter identification information and associated channel estimates received from the PPC decoder logic 220. For example, the locations of the transmitters T1-T5 are known to the network entity. These channel estimates are used to determine the distance of the device from its location. The position decision logic 221 then triangulates the position of the device 206 using a triangulation technique.

During operation, each of the transmitters 202 encodes the transmitter identification information on at least one of the active interlaces of the PPC symbols associated with the transmitter. PPC generator logic 210 operates to determine which symbol is the active symbol for a particular transmitter based on network provisioning information 224. When a transmitter does not interleave its identification information in the role of its active symbol, PPC generator logic 210 causes the transmitter to transmit idle information on the idle interlace of the remaining PPC symbols. Because each transmitter transmits energy in each PPC symbol (i.e., interleaved or idle interleaved), the transmitter power does not experience fluctuations that would interfere with network performance.

When device 206 receives PPC symbol 234 from transmitters T1-T5 on PPC 202, it decodes the interlaced transmitter identifier from each of the PPC symbols. Once the transmitter is identified from each PPC symbol, the device is able to determine the channel estimate of the transmitter based on the available system timing. The device continues to determine the channel estimate of its identified transmitter until a channel estimate (i.e., preferably four estimates) for multiple transmitters is obtained. Based on these estimates, position decision logic 221 operates to triangulate position 228 of the device using standard triangulation techniques. In another example, location decision logic 221 operates to transmit the transmitter identifier and associated channel estimate to another network entity that performs triangulation or other positioning algorithms to determine the The location of the device.

In one example, the positioning system includes a computer program having one or more program instructions ("commands") stored on a computer readable medium, the computer program providing the positioning described herein when executed by at least one processor The function of the system. For example, instructions can be loaded into PPC generator logic from a computer readable medium such as a floppy disk, CDROM, memory card, flash memory device, RAM, ROM, or any other type of memory device. 210 and/or PPC decoder logic 218. In another example, the instructions can be downloaded from an external device or network resource. The instructions operate when executed by at least one processor to provide an example of a positioning system as described herein.

Thus, the positioning system operates at the transmitter to determine an active PPC symbol, wherein a particular transmitter interleaves its identification information as a function of its symbol. The positioning system is also operative at the receiving device to determine a channel estimate for the transmitter identified in the received PPC symbol and to perform a triangulation technique to determine a device position.

FIG. 3 shows a transmission hyperframe 300 that can be used in the system of FIG. 1 or 2. As shown, each hyperframe 300 includes a preamble 302, one or more data frames 304 (eg, four data frames in the example of FIG. 3), and a PPC/reserved symbol 306, the preamble 302 including Time division multiplexing (TDM) pilots (eg, TDM1 and TDM2), wide area identification channel (WIC), local area identification channel (LIC), and additional information symbol (OIS) 302.

According to an example, the PPC symbols can be configured such that the cyclic first code length is increased to one-half the number of sub-carriers, such as to 2048 chips in the example of 4096 sub-carrier symbols. For example, the increased loop first code allows the receiving device receiving the hyperframe to more fully account for the variability of channel delay spread. Thus, according to an example, each physical layer (PHY) PPC symbol will have a duration of 6161 chips (a loop of the first code of 2048 chips + a window of 4096 chips + 17 chips). It should be noted that the disclosed example assumes a "4K" (ie, 4096-chip window) Fast Fourier Transform (FFT) mode. Additionally, according to this example, as will be discussed later, the Medium Access Control (MAC) PPC symbol can be defined to be equal to one PHY PPC symbol having a duration of six interlaces with 6161 chips per symbol (ie, PHY PPC for "4K" FFT). However, the PPC symbol structure can be configured such that it is similar to the data symbol structure for the corresponding FFT mode (eg, 1K, 2K, or 8K). Therefore, again assume that the loop first code is equal to one and a half of the FFT window and 17 window chips. For 1K and 2K FFT modes, the number of chips per symbol will be (for example) 1553 chips (1024 chips +) 512 cycles first code + 17 window chips) and 3,089 chips. The number of MAC PPC symbols in a superframe (for example, 8) will still be the same as the 4K mode. It should be noted that this number is provided by way of example only, and those skilled in the art will appreciate that other PPC symbol configurations and durations are possible within the scope of the present disclosure.

As can be seen from the above discussion, the cycle first code of the PPC symbol will be different from the data symbol in all FFT modes. For example, as mentioned above, the loop first code for the 4K FFT mode will be 2048 chips instead of the more typical 512 chips for the data symbols.

4 shows a functional diagram of an interleaved structure of OFDM symbols 400 for PPC symbols transmitted by an active transmitter. According to one example based on the above illustrative numbers, symbol 400 will include 4096 subcarriers divided and grouped into eight interlaces (I ₀ -I ₇ ) as shown, such that each interlace contains 512 subcarriers, such The frequency or carrier frequency of the subcarriers is usually not adjacent. As mentioned previously, it may be desirable to use a receiver. First, a receiving device needs to use the pilot subcarriers in the symbol to determine a channel estimate. Second, a receiving device needs to determine the identifier of the transmitter corresponding to the channel estimate.

The interleaving in the active symbol 400 is used to transmit the pilot carrier tone and the transmitter identification information. In the particular example of FIG. 4, the subcarriers of symbol 400 are labeled with a first portion of reference numerals 402, 404, 406, and 408 (ie, interlaced I ₀ , I ₂ , I ₄ , I ₆ ) and labeled 410. Interlace I ₁ is interleaved for the purpose of transmitting pilot carrier frequency modulation. In the case of interleaving I ₀ , I ₂ , I ₄ , I ₆ , by wide-area scrambler seed (ie, wide-area discriminator bit (WID)) and local scrambler seed (ie, local area) The discriminator bit (LID) disturbs the pilot to ensure maximum interference rejection across the (etc.) network. In addition, interlace I ₁ is used by the active transmitter to transmit pilots that are only scrambled by WID (eg, set the LID to zero) to reduce the number of hypotheses that the receiver must assume, and thus reduce the number of processing In order to jointly determine the WID and LID.

According to a particular example, the wide area identifier WOI ID and the local area identifier LOI ID are available at higher layers and are actually available when decoding OIS symbols. At the physical layer, transmissions across various regions and sub-regions (ie, wide and local) are distinguished by using different scrambler seeds (WID and/or LID). In an example, the WID can be a 4-bit field and used to separate wide-area transmissions, and the LID can be another 4-bit field for separate local transmissions. Since there are only 16 possible WID values and 16 possible LID values, these WID and LID values may not be unique throughout the network deployment. For example, a given combination of one of WID and LID can potentially be mapped to multiple WOI IDs and LOI IDs. Despite this, network planning can be done so that the reuse of WID and LID will be geographically separated. Therefore, it is possible to unambiguously map a given WID and LID to a particular WOI and LOI in a given neighborhood. Thus, at the physical level, the PPC waveform is designed to carry WID and LID information (ie, disturbed with interlaces I ₀ , I ₂ , I ₄ , I ₆ , and I ₁ ).

As noted above, the transmitter in the active state should transmit at least 2048 pilots to enable the receiver to estimate the channel with the required delay spread. This corresponds to the four interlaces of the active transmitter. The four active interlaces (eg, I ₀ , I ₂ , I ₄ , I ₆ ) are then scrambled using the wide and local WIDs and LIDs to which the transmitter belongs. One of the symbols will therefore first extract the WID and LID information from the pilot in the interlace of a PPC symbol, and then use the WID/LID information to obtain the channel estimate from the particular transmitter. The scrambling by WID and LID also provides suppression of interference from transmitters in adjacent local area networks.

However, the corresponding WID/LID identification step at the receiver may become complicated. For example, if each interlace is scrambled using both WID and LID, the receiver will have to jointly detect the WID and LID seeds used to perform the scrambling. There are 16 possibilities for each seed, so that the receiver will have to try 256 hypotheses for common detection. Therefore, receiver detection can be simplified by allowing independent detection of WID and LID seeds. Thus, in the example of the disclosed, the PPC waveform includes only WID values having to disrupt the pilot subcarriers of another group or interleaved (e.g., interleaved labeled with reference numeral _1, I 410), wherein the LID bit values are set It is 0000.

In addition to the above, the apparatus and method of the present invention includes the use of another portion of the subcarrier to transmit specific transmitter identification information contained in the PPC symbol 400. In particular, this second portion of the subcarrier contains another non-zero interlace in a PPC symbol. According to the example illustrated in Figure 4, the interlace is marked with reference numeral 412, I ₃ may comprise a transmitter identification information, but any other free interlace. This self-contained transmitter identification information allows the receiver to process a PPC independently of normal hyperframe processing. In particular, the acquisition of the transmitter identification can only be obtained from the PPC processing, and will only rely on the detection of the TDM1 pilot channel processed by the PPC, which is used for coarse timing detection. In addition, this produces a transmitter-specific PPC channel that can be used to support location-specific applications in the communication network, as each transmitter inherently has a non-interfering channel. Thus, for example, each transmitter can be configured to impart information about a particular application, except for transmitter identification information, via a transmitter specific channel. Therefore, interleaving within other PPC symbols can be utilized to communicate specific application data to the receiving device.

The particular type of information included in the transmitter identification information may first include a transmitter identifier bit that provides a unique identifier for the transmitter. In an example, the number of expected bits can be 18, but any suitable number of bits can be utilized. Also, additional signal transmission information bits may be allocated in the transmitter identification information to indicate more specificity with respect to other information to be transmitted. For example, the signal transmission information can be used to indicate to the receiving device whether the transmitter uses other symbols to transmit other information and how many other symbols will be used. In an example, the signal transmission information includes 3 bits. Therefore, in this example, the payload of the transmitter identification information will be 21 bits (18 bits for the transmitter ID + 3 bits for the signal transmission information), but may cover less or More numbers.

The transmitter identification information may also include an error detection code, such as a cyclic redundancy check (CRC). In an example, the CRC function can be defined by the CRC polynomial g(x) = x ⁷ + x ⁶ + x ⁴ +1, which produces a 7-bit CRC.

Interlace is marked with 412 I ₃ (although any other free interlace) form may comprise one or more transmitter location coordinates (e.g., GPS longitude, latitude and or altitude coordinates) of the form of the transmission identification information. In addition, the slot 3 as a possible transmitter identification indication repository may also include network delay information. It should be noted that interleaving is also referred to herein as a slot when used with transmitter location identification. Accordingly, in one aspect, the groove 3 (i.e., the I interlace ₃₎ can be held transmitter (TX) location information.

In one method (Method 1), regardless of whether the transmitter identification information or other parameters are signaled in the PPC packet, a fixed bit PPC packet length of, for example, 80 bits is used. This provides 10 blocks of 8 bits each, each of which is converted to 100 bits. A longer payload can be achieved compared to a shorter length PPC package. In testing and implementation, a single PPC packet size is beneficial. The packet type (field assignment) is self-contained and allows for scalability to include other parameters such as transmitter power and number of hyperframes. Two methods of implementing how to allocate PPC bits are shown in options 1 and 2 shown on slide 1. Red-Muller coding can be used for both implementations. Other variants include the Reed-Muller code using the same base (64, 7), but truncated to (41, 7). The Transmitter ID is repeated twice in Option 2 instead of 50 bits. Other coding schemes are possible during the generation of 68 bits from the 18-bit transmitter ID.

In another method (Method 2), a 56-bit PPC packet is used regardless of whether the transmitter ID information is signaled in the PPC packet. One bit allocation is illustrated on slide 2. Again, other attributes and benefits of Method 2 are shown on slides 3 and 4.

A third method (method 3) is set forth on the attached slides 5 through 8, and the same format assignment is shown on slide 17. Since each transmitter can be in one of three states (ie, inactive, identified, or reserved) within each PPC MAC time unit, in the case of method 3, the PPC retention state is used. As a transmitter specific channel. In addition to network latency, the information includes transmitter ID information as well as the latitude, longitude and altitude of the transmitter. This method allows turbo loading to be used for larger loads. As shown on slide 6, for a payload of 1000 bits, Turbo coding supplies a more robust encoding than the Reed-Muller encoding. As shown on slide 5, an embodiment includes four pilot slots and three data slots. The PPC Transmitter ID information and the PPC Transmitter Location Information can be placed in any of the data slots. Another embodiment includes five data slots and two pilot slots. Compared with the three data slots, there are more redundancy in the case of the five data slots. As can be further seen in FIG. 4, two interleaved or subcarrier groups (eg, interlaces I ₅ and I ₇ in the example of FIG. 4, which are represented by reference numerals 414 and 416) will be in the active PPC symbol 400. Idle or become zero. Next, the energy in each interlace is (8/6) times the total OFDM symbol energy to ensure an essentially constant power level for each OFDM PPC symbol. However, it should be noted that the power or energy distribution between the interlaces used in the active symbol 400 (e.g., interlace I ₀ -I ₄ and interlace I ₆ ) need not be uniform. Rather, energy can be distributed disparately in different interlaces. For example, the energy of the interlaced I ₃ can be set to 8E/3, and the energy of the interlaced I ₀ , I ₂ , I ₄ , I _{6 and} the energy of the interlaced I ₁ can be set to 2E/3, or in other words, interleaved I ₃ The energy level is four times the energy of each of the five interlaces I ₀ , I ₁ , I ₂ , I ₄ or I ₆ .

Assuming the exemplary hyperframe structure discussed above, using eight available PPC symbols per hyperframe, a hyperframe can support eight transmitters in a local area. However, in some deployments, the number of transmitters in a local area can be higher than eight. In addition, only transmitters in a particular local area are constrained to be orthogonal in time. Thus, network planning can be used to schedule transmitters across different localities such that self-interference in the network is avoided or at least mitigated.

In addition, it is desirable to support more than 8 transmitters per local area. For the purposes of the example, assume that 24 transmitters will be supported in one local area. To support this deployment, the network can be configured such that each transmitter will transmit an active PPC symbol once every three (3) hyperframes. In this case, the network plan and additional parameters can be used to inform the transmitter of when its respective active state will occur and when it will transmit the identification information on the assigned role. Therefore, the periodicity of the three hyperframes can be programmed at the network level so that the system can be fully tuned to support additional transmitters. The periodicity used by the network can be kept constant throughout the network deployment, simplifying network planning and additional information for transmitting information. In one example, periodic information used in the network is broadcast in the higher layers as additional item information to allow for easier programmaticity of this parameter. In addition, in the case where there are 30 available PPC symbols in each local area, the constraints on network planning to ease the interference at the boundary of two different local areas are also relaxed.

5 shows an exemplary PPC symbol transmitted by a passive or inactive transmitter in a network such as the network illustrated in FIGS. 1 and 2. As can be seen, an inactive PPC symbol 500 has become zero the I ₀ to ₁₆ interlace. Interlace I ₇ (mentioned by numeral 502) is the only interlace with non-zero energy in passive transmitter symbol 500. The pilot transmitted in interlace I ₇ does not contain meaningful data or information, and the interlace can be referred to as a "dummy" interlace. In accordance with the disclosed examples, the energy in interlace I ₇ is also scaled to 8 times the energy available for interleaving per OFDM symbol to satisfy constant OFDM symbol energy constraints. The transmission of the passive or inactive PPC symbol 500 ensures that the transmission therein does not interfere with the pilot of the active transmitter, as illustrated in Figure 4, the pilots are interleaved I ₀ , I ₁ , I ₂ , I ₄ and I ₆ transmitted on.

Figure 6 illustrates apparatus 600 for encoding transmitter identification in the interleaving of PPC symbols in effect, such as the interlacing illustrated in Figure 4. Apparatus 600 first includes a module 602 for setting or determining a transmitter identifier (TxID) bit and assigning a bit. As discussed above, the number of bits for the TxID bit and the allocated bit can be set to 18 and 3, respectively. Assuming this embodiment for purposes of illustration, 21 bits are passed from module 602 to module 604, which is configured to convert CRC bits (eg, as described above, seven bits) Add to TxID bit and allocate bit. Module 604 then passes the total bits (which may be collectively referred to as "transmitter identification information") to an interleaver 606 (eg, a block interleaver). Assuming that 28 bits are passed, the block interleaver 606 can be configured as a 4 x 7 matrix in which the bits are written row by row and the bits are read out column by column to achieve interleaving. However, it should be noted that various other types of suitable interleaves that are contemplated for use with the presently disclosed devices and methods are contemplated by those skilled in the art.

The interleaved bits are read out to an encoder 608 to encode the bits according to a predetermined coding scheme. In an example, encoder 608 can encode the equal bits using a Reed-Muller (RM) error correction code, such as a first order (64, 7) RM code. In this example, interleaver 608 passes 28 information bits to encoder 610. With a (64, 7) RM code, the 28 information bits will be encoded to obtain four 64-bit code blocks. However, in a particular example, when 250 encoded bits are needed to fit a particular number, the resulting 256 bits will be too large. Thus, the 2 bits of the (64, 7) RM code can be punctured, resulting in a (62, 7) RM code as illustrated by the culling module 610 in the encoder 608. In a particular example, the bits corresponding to locations 62 and 63 in the Red Muller codeword can be eliminated. Therefore, when encoding the 28 information bits, the result will be 248 encoded bits. As further illustrated by zero insertion module 612 within encoder 608, two zeros can be appended to the four code blocks to achieve 250 encoded bits. A receiver will again assume that the bits are zero during decoding.

FIG. 7 illustrates an exemplary hardware circuit 700 that can be used in an encoder to generate an RM code and, more specifically, in an encoder 608. As illustrated, hardware circuit 700 receives a 7-bit input as illustrated by input 702 that receives input bits m ₀ through m ₆ . Circuitry 700 also includes a k-1 (e.g., 6) bit counter 704 that receives a clock input to increment counter 704. With the respective multiplier 706 to the output of counter 704 is multiplied by each of input bits m ₀ to m ₅ in the. In addition, the most significant bit m _{6 is} multiplied by a constant binary "1" value (block 708). The output of the multiplier is summed by summing block 710 and an RM (64, 7) codeword is output, which is a series of 64 bit values c ₆₃ to c ₀ . It should be noted that in an example, the culled code can be obtained by discarding the values c ₆₂ and c ₆₃ .

Returning to Figure 6, once the transmitter information is encoded by encoder 608, repeater 614 can be used to ensure that the number of bits matches the particular number of the communication system. This repetition supplies an increase in processing gain at the receiver. From the above example, the 250 bits output by encoder 608 can be repeated four times for a total of 1000 bits, which would result in a processing gain of 6 dB at the receiver. After the repeater 614 repeats the bits, the bits are scrambled as illustrated by the scrambler 616. In an example, the bits may be scrambled with a sub-block based on a PPC symbol index (eg, 0 to 7 in this example) and a trough mask that is the same as the interlace index. After the disturbance, the modulator 618 modulates the distracted bits for transmission according to any of a number of modulation schemes. In the example above where 1000 bits are used, the bits can be mapped to QPSK symbols, which results in 500 QPSK symbols. In an OFDM physical layer symbol with eight interleaved 4096 data subcarriers divided into 512 bits each, 500 QPSK symbols will fill an interlace, depending on the PHY layer symbol to have a duration of 6475 chips. The mapping of temporal PPC symbols spans one or more physical layer symbols. It should be noted that the use of repeater 614, scrambler 616, and modulator 618 is only one example of a modulation scheme, and those skilled in the art will appreciate that other suitable modulation schemes can be used with the disclosed methods and apparatus.

Further, in the above example, it is assumed that one of the receiver modes has a 4096 sample (i.e., "4K") fast Fourier transform (FFT) window. It should be noted that other FFT modes (eg, 1K, 2K, or 8K) using the same methods and devices are contemplated.

After being modulated by modulator 618, for example, the modulated symbols can be interleaved by interleaver 620 to mitigate frequency variations that may occur during transmission on the transmission channel. Additionally, the interleaved modulation symbols are mapped to one or more PPC Physical Layer (PHY) symbols depending on the FFT mode. In the above example of 4K FFT mode, 500 modulated symbols are interleaved and mapped to a PHY PPC symbol. In another example of a 2K FFT mode, interlaced symbols can be interleaved, or more interlaced symbols can be interleaved in different interlaces (interlaced).

FIG. 8 shows a method 800 for providing transmitter identification in a wireless system, such as the system illustrated in FIGS. 1 and 2. For example, method 800 is suitable for use by a transmitter in a network to allow a receiving device to identify a transmitter and to determine positioning based on the transmitter identification. In one example, method 800 can be performed by a transmitter configured as illustrated at 214 in FIG.

As shown, after the method 800 begins, the process flow proceeds to step 802 where the transmitter identification information is determined. As an example, as illustrated by FIG. 2, this information can be learned from the network provisioning material 224 sent to the transmitter 214. Alternatively, Transmitter Identification (TxID) information may be inherent to the transmitter based on a specified network plan.

After the TxID information is determined or retrieved, as explained by step 804, the transmitter receives information about whether the destination transmitter for the PPC symbol is in an active state or an idle state. As previously explained, the active transmitter is interleaved for transmission in the presence of a particular current PPC symbol, while the currently idle transmitter transmits over an idle or dummy interlace of the current PPC symbol. In one example, network logic (e.g., logic 212) in a transmitter (e.g., transmitter 214 in FIG. 2) receives a current transmission from network provisioning material 224 from a suitable network management entity or device. An indication of the status of the device.

In decision step 806, a determination is made whether the transmitter of the current PPC symbol is in an active mode or an idle mode. As an example, this determination can be made by the PPC generator logic 210 in the transmitter 214 shown in FIG.

If the transmitter for the current PPC symbol is in effect, then the process flow proceeds to step 808, in which the scrambling performed by the pilot to the first portion of subcarriers (e.g., interlace I ₀ with WID and LID seeds, The pilot is encoded on the subcarriers in I ₂ , I ₄ , and I ₆ . Further, as shown in step 810, with only WID seeds scrambling pilots to another in a first portion (e.g., interlace ₁ I of subcarriers) subcarrier encoding the part of the pilot. It should be noted that the designation of the "first part" of the subcarrier means the portion of the plurality of available subcarriers for transmitting the pilot carrier tone, such as the subcarriers of the interlaces I ₀ , I ₂ , I ₄ , I ₆ . and their interleaving I ₁ of subcarriers. As an example, the encoding of the pilots as illustrated by steps 808 and 810 can be performed by transmitter logic 208 and PPC generator logic 210 illustrated in FIG.

As illustrated by step 812, one of a second portion of subcarriers (e.g., subcarriers in interlace ₃ in the I) encoding transmitter identification (the TxID) information. As discussed previously in connection with the examples of Figures 4, 6, and 7, the encoding of the TxID information is done in accordance with a predetermined coding scheme. As an example, the encoding of the TxID as shown by step 812 can be performed by the transmitter logic 208 and the PPC generator logic 210 illustrated in FIG.

After encoding the TxID, as explained by step 814, the PPC symbols are transmitted. The process stream may then return to step 804 to encode a PPC symbol below the same or the next hyperframe. As an example, the transmission of the symbol can be performed by a transmitter logic, such as logic 208.

If, as determined at decision step 806, the current PPC symbol is not an active symbol, then as illustrated in FIG. 8, the processing flow instead proceeds to step 816. In this case, as shown by step 816, the current PPC symbol group of the plurality of available subcarriers available subcarriers designated (e.g., interlace I ₇₎ is encoded with idle information. As an example, this encoding can be performed by PPC generator logic 210 and transmitter logic 208. After encoding in step 816, the process flow proceeds to step 814 to transmit the PPC symbol.

Additionally, it should be noted that the power level of the PPC symbol can also be performed as part of the transmission of the PPC symbol at step 814. As discussed previously, this ensures a constant symbol power of the SFN system. As an example, power adjustment can be performed by transmitter logic 208.

Method 800 thus operates to provide a system to provide transmitter identification via PPC symbols from a transmitter. It should be noted that the method 800 is merely illustrative of one embodiment, and variations, additions, deletions, combinations, or other modifications of the method 800 are possible within the scope of the present disclosure. Although the method of FIG. 8 is shown and described as a series or multiple acts for purposes of ease of explanation, it should be understood that the processes described herein are not limited by the order of actions, as some actions may differ from those shown herein. And the order in which the order is described occurs and/or occurs concurrently with other acts. For example, those skilled in the art will appreciate that a method can be either represented as a series of related states or events, such as in the form of a state diagram. Moreover, in accordance with the present exemplary methods disclosed, not all illustrated acts may be required to implement a method.

Figure 9 illustrates an apparatus for transmitting PPC symbols having transmitter identification information. Device 900 can be implemented as a transmitter (such as transmitter 214 in Figure 2) or as a component of a transmitter. Apparatus 900 includes a module 902 configured to receive network provisioning data (e.g., transmission status information). Module 902 can receive information such as the provisioning material 224 disclosed in FIG. 2, or any other suitable information about the status of the transmitter, such as whether the transmitter is active or idle for PPC transmission, or transmitter identification information. (TxID). As an example of an embodiment of module 902, one or more of transmitter logic 208, PPC generator logic 210, and network logic 212 may be utilized.

Apparatus 900 further includes a module 904 for encoding pilot information on a first portion of a plurality of subcarriers in a symbol of one of the active transmitters using the seed WID. As examples of this embodiment of the function module, the plurality of sub-carriers of the first portion may be staggered is divided to I and treated with ₁ WID seed (e.g., the LID set to 0000) to disrupt their subcarrier. Another module 906 for encoding transmitter identification information on another portion of the first portion of the plurality of subcarriers of the symbol using the WID and LID seed is illustrated in FIG. In a particular embodiment, module 906 can be configured to encode pilot information using the subcarriers of interlaces I ₀ , I ₂ , I _{4 ,} and I ₆ .

Although the module 904 and the display 906 is divided into two parts in the example of FIG. 9 but these modules may be configured for a subcarrier belonging to the first portion of the plurality of sub-carriers (i.e., interlace I _0, A single module that encodes pilot information on I ₁ , I ₂ , I _{4 ,} and I ₆ ). It should be noted that as an example of an embodiment of modules 904 and 906, one or more of transmitter logic 208, PPC generator logic 210, and network logic 212 may be utilized.

900 further comprises a means (e.g., interlace ₃ in the subcarriers I) up identification code transmission (the TxID) information module in accordance with the plurality of subcarriers of the second portion 908 a predetermined coding scheme. It should be noted that as an example of an embodiment of module 908, one or more of transmitter logic 208, PPC generator logic 210, and network logic 212 may be utilized.

Apparatus 900 also includes a module 910 configured to transmit a PPC symbol, the PPC symbol including an encoded pilot on a first portion of the plurality of subcarriers and a TxID on the second portion. Embodiments of module 910 can use transmitter logic 208 or PPC generator logic 210, or a combination thereof.

It should be noted that modules 902, 904, 906, 908, 910, and 912 can be configured to execute program instructions or code to provide at least one aspect of a system including transmitter identification and positioning as described herein. The processor is implemented. Additionally, a memory device 914 or equivalent computer readable medium can be provided in conjunction with the at least one processor for storing the program instructions or code.

Figure 10 shows a method 1000 for receiving a symbol including transmitter identification information. For example, method 1000 is suitable for use by a receiving device in a network to receive and decode PPC symbols transmitted by a currently active transmitter, such as for transmitter identification and position determination. In one example, method 1000 can be performed by a receiver configured as illustrated at 222 in FIG. In addition, method 1000 is used.

As shown, once the method is started for the received symbols, the process flow proceeds to step 1002. At step 1002, at least one PPC symbol is received by the receiver. In a particular example of a receiver in 4K mode, receipt of the at least one PPC symbol involves collecting 4096 samples of the input signal. As shown, step 1002 can also include measuring energy in one or more interlaces, such as a scaling factor for setting the FFT and for determining a threshold energy value for determining WID and LID values, as will be discussed below. . In a particular example, the energy in interlace I ₁ can be measured from a time domain interleaved sample of a first received PPC PHY symbol. Further, also measuring the unused interlace (e.g., interlace I ₅₎ to determine the total energy of the interference (e.g., by the introduction of heat and / or signals) is measured on the PPC channel. It should be noted that in another example, a hardware in a receiver (such as receiver 222) can be configured to interrupt a processor, such as a digital signal processor (DSP), so that the programming will be performed by the hardware. The FFT scale factor used and the thresholds. As an example, the FFT scaling factor is set to improve the quantization noise floor of the signal from the weak transmitter.

Then the processing flow proceeds to step 1004, from a group of subcarriers comprising only disturb the pilot to determine WID WID; i.e., as previously discussed the interleaving I _1. In an example, this determination can be made by receiver logic 216 and PPC decoder logic as illustrated in FIG. In another example of the 4K mode, it should be noted that a 512 point FFT can be utilized which produces frequency domain samples. In an exemplary system, WID detection will include repeating descrambling sequences (repeated 16 times in an exemplary system using 16 WID seeds), inverse FFT to generate time domain samples, and the samples The energy threshold is compared (based on the energy measurement for the interlace) and the energy values of the samples above the threshold are accumulated to determine which hypothetical WID value produces the maximum energy. The WID that produces the maximum energy will correspond to the WID value.

After determining the WID value, as explained by step 1006, the LID value is next determined. Specifically, the LID is determined from a group of subcarriers containing pilots scrambled with WID and LID; that is, interlaced I ₀ . In an example, this determination can be made by receiver logic 216 and PPC decoder logic as illustrated in FIG. In another example of the 4K mode, it should be noted that a 512 point FFT can be utilized to generate frequency domain samples. In an exemplary system, LID detection will include repetitively repetitive sequences using the WID detected from step 1002 (repeated 16 times in an exemplary system using 16 WID seeds and 16 LID seeds), An inverse FFT is performed to generate time domain samples, and their samples are compared to an energy threshold (based on energy measurements such as interleaving _one of the interlaces I ₁ ) to determine which hypothetical LID value produces the maximum energy. The LID that produces the maximum energy will correspond to the LID value.

In step 1008, a plurality of subcarriers encoded with pilots are then used to determine a channel estimate. In particular, the channel estimates can be obtained using the interlaces I ₀ , I ₂ , I _{4 ,} and I ₆ . In an example of a 4K mode receiver, a 512 sample FFT can be performed on each of the four interlaces to obtain a frequency domain sample. The samples are then descrambled using the previously obtained WID and LID seeds. The descrambled pilot in the frequency domain can then be input to a 2048 (2K) sample IFFT to obtain a time domain channel estimate. Once the time domain channel estimate is determined, the energy of each tap to be read by a processor, such as a DSP, is calculated and stored. Further energy can be based on the unused interlace (e.g., interlace I ₅₎ of the previously measured amount of the calculated energy is compared with a threshold to determine signal power in the current role of the transmitter. It should be noted that as an example, the process of step 1008 can be performed by receiver logic 216 and PPC decoder logic as illustrated in FIG.

In yet another example of a procedure for determining channel estimation, assuming the above example, it should be noted that the 2K time domain channel estimate may be frequency-staggered back to the original 512 time domain point or sample. An example of a frequency stack pattern is given by the following relationship:

among them For time domain channel estimation, s is data interleaved and q is a channel frequency group index, where in this particular example each channel frequency group contains 512 channel taps. Therefore, as an example, if the related data interleaving (s) is equal to 3, then the above equation (1) becomes:

Determine the channel estimate as given in equation (2) A phase ramp can then be applied to the time domain estimate as given by:

For the purposes of decoding interleaving (interleaved data interleaving with transmitter identification information), the above example assumes that interlace s = 3, or in other words, the interlace I ₃ given in the example of Figure 4, which contains the TxID. Then right A 512 sample FFT is performed to obtain channel estimates from the frequency domain samples.

After step 1008, the process flow proceeds to step 1010 where a dedicated material interleave with transmitter identification information (TxID) is decoded. Illustrated in Figure 4, this dedicated interlace may be interlace I _3. As a specific example of a process for decoding in a receiver in a 4K FFT mode, as mentioned above, may be dedicated stack of interleaved data frequency (I ₃₎ 512 performs FFT samples to produce frequency domain samples. The processing of step 1008 may further include using the corresponding channel estimates having the QPSK modulation interlace I ₃ bits 1000 generated logarithm likelihood ratio (LLR). The LLRs can then be deinterlaced similar to the deinterlacing of data symbols. The LLRs of 1000 bits can then be averaged over four cycles to achieve an OLR of 250 bits. For example, this averaging can be done based on the following relationships:

among them It represents an average LLR for a k ^th value. After averaging the LLRs to produce 250-bit LLRs, they can be processed by a processor, such as a DSP. It should be noted that in an example, the averaging can be performed by hardware implemented by, for example, receiver logic 216 and/or PPC decoder logic 218. Additionally, the processor may be comprised by the illustrated receiver logic 216 and/or PPC decoder logic 218 illustrated in FIG. 2, which is not necessarily meant to include only hardware logic devices.

After delivering the 250 bit LLR to the processor, Red Muller decoding can be performed. For example, a 64-dimensional fast Hadamard transform (FHT) of LLR can be computed for each code block, assuming that the previously discussed exemplary encoding uses RM (64, 7) encoding. In addition, since only 62 of the 64 bits containing the (64, 7) RM code are transmitted by culling in the exemplary encoding discussed, the receiver can replace zero for decoding purposes. The bit that was removed. Therefore, the transform F is equal to H × L , where H is a 64×64 Hadamard matrix, and L represents a block corresponding to an RM code (ie, 7 bits, assuming that the above exemplary code uses 28 bits) Four code blocks) LLR. After the transformation F has been calculated, the position of the entry of the maximum magnitude within the transformation F is determined. Due to the characteristics of the FHT, the binary representation of the location of the maximum magnitude entry will provide six of the seven message bits in the RM code block. The sign of the maximum magnitude entry provides a seventh message bit, where the message bit is 0 when the sign is positive and 1 when the sign is negative.

After decoding all RM code blocks containing transmitter identification information (i.e., four RM code blocks in this example), a Cyclic Redundancy Check (CRC) can be checked to ensure that the received message bit is ( High probability) no error. In the case of CRC matching, the transmitter identification information can then be used by the receiver, and the WID, LID and power measurements can also be used by the receiver.

The transmitter data within the transmitter identification information can then be used by the receiving device to identify the transmitter that issued the active PPC symbol (as indicated by step 1012). Since the PPC symbol includes self-contained transmitter identification information, the receiving device does not need to perform additional processing to identify the transmitter, thus providing fast and active transmitter identification. Additionally, it should be noted that this information can be used with one or more of channel estimation, WID, LID, and power measurement information to determine location information about the receiving device relative to the (etc.) transmitter, such as via triangulation. Or any other suitable technology.

After the process of step 1012, the process flow proceeds to decision step 1014. A determination is made whether to indicate additional or other PPC symbols from the signal transmission information within the transmitter identification information. If no additional symbols are indicated, then process 1000 ends. Alternatively, if additional symbols are indicated, then process flow proceeds from step 1014 to step 1016 to further decode the additional symbols. It should be noted that this process can be accomplished in a manner similar to that discussed above in connection with one or more of steps 1002 through 1008.

It should be noted that the process for decoding symbols for other FFT modes at the receiving device is also covered. For example, assuming a 2K FFT mode, a receiving device collects 2K samples from each symbol. A 256 point FFT can then be performed for each time domain interlaced sample in the symbol. The frequency domain interlaced samples from the 256-point FFT can then be concatenated with samples from across two symbols (eg, PHY symbols). As an example, if the set of 256 interlaced samples from a first symbol is represented as Y ₀ = {y _{0 , 0} , y ₁ , ₀ , y _{2, ο} , ..., y _{255 , 0} } and from a The set of 256 interlaced samples of the two symbols are represented as Y ₁ ={ y _0,1 , y _1,1 , y _2,1 ,...,y _255,1 } , and the resulting series of the two sets of samples can be connected in series Expressed as Y={ y _0,0, y _1,0 ,y _2,0 ,...,y _255,o ,y _0,1 ,y _1,1 ,y _2,1 ,...,y _{255 , 1} } . After 512 samples from multiple PHY symbols are concatenated, as discussed above in connection with one or more of steps 1002 through 1016, WID and LID detection, channel estimation, and LLR generation may be similar to the 4K FFT mode of operation. deal with.

In another example of a 1K FFT mode, a 128 point FFT is performed on time domain interleaved samples from each PHY PPC symbol. Similar to the above example, the resulting frequency domain samples from the 4 PHY PPC symbols are concatenated to form an interlace. In yet another example of an 8K FFT mode, it should be noted that one interlace contains 1000 subcarriers. Therefore, the processing by the receiving device will perform channel estimation using 1K FFT/IFFT processing and 4K IFFT processing.

The method 1000 thus operates for receiving and processing symbols including transmitter identification information at the receiving device. It should be noted that the method 1000 is merely illustrative of one embodiment, and that variations, additions, deletions, combinations, or other modifications of the method 1000 are possible within the scope of the present disclosure. Although the method of FIG. 10 is shown and described as a series or multiple acts for purposes of ease of explanation, it should be understood that the processes described herein are not limited by the order of actions, as some actions may differ from those shown herein. And the order in which the order is described occurs and/or occurs concurrently with other acts. For example, those skilled in the art will appreciate that a method can be either represented as a series of related states or events, such as in the form of a state diagram. Moreover, in accordance with the present exemplary methods disclosed, not all illustrated acts may be required to implement a method.

11 shows another example of a receiver device or alternatively a device 1100 for use in a receiver in a system having transmitter identification information. Apparatus 1100 includes a module 1102 for receiving at least one PPC symbol and determining energy in one or more interlaces, such as interleaved (eg, I ₁ ) and unused interlaces (eg, I ₅ ). This energy determination can then be shared with other modules within device 1100 as illustrated by the connection to communication bus 1104. It should be noted that this busbar architecture is merely exemplary and is intended to illustrate that various communications can be made between modules within device 1100.

Since 1100 also includes means for interleaving a predetermined (e.g., interlace I ₁₎ determination module 1106 WID seed. As explained earlier, the determination of the WID can include determining the threshold based on the previously measured energy (such as by the module 1102). Transmitting the WID determined by module 1106 to module 1108 for use WID from a predetermined interlace (e.g., interlace I ₀₎ is determined LID. Moreover, the measured energy is used by the module 1108 to detect the LID, and the measured energy is determined by the module 1102.

Further comprising means for self-acting 1100 interleaved (e.g., interleaved I _0, I _2, I ₄ and I ₆₎ determining a channel estimation module 1110. As previously explained, for example, the determination of the channel estimate can include comparing the energy calculation of the tap to an energy threshold, such as the energy threshold determined by module 1102. Also includes means for decoding dedicated interlace (e.g., I ₃₎ to determine the transmitter identification information (the TxID) modules 1112. As an example, module 1112 can perform a decoding process as described in detail above in connection with step 1010 of FIG. Additionally, a module 1114 for determining a transmitter identification code based on TxID (and receiving device positioning based on transmitter ID, channel estimation, and energy measurements) is provided in device 1100. Module 1114 can include functionality to perform a cyclic redundancy check to ensure that received message bits are error free, and if there are no errors, trigger for a processor such as processor 1116 (which can be DSP or other suitable processing) The transmitter identification, WID, LID, and measured power used are used to fill the transmitter ID table in the receiving device 1100. The transmitter ID table can be included in the memory device 1118 in communication with the processor 1116 and/or the modules in the device 1100.

It should be noted that modules 1102, 1106, 1108, 1110, 1112, and 1114 can be implemented by at least one processor configured to execute program instructions to provide an example of a system including transmitter identification and positioning as described herein. In an example, modules 1102, 1106, 1108, 1110, and 1112 can be implemented by receiver logic 216 and/or PPC decoder logic 218. In an example, module 1114 is implemented by position determination logic 221. Additionally, a memory device 1118 or equivalent computer readable medium can be provided in conjunction with the at least one processor for storing program instructions or code.

It should be noted that general purpose processors, digital signal processors (DSPs), special application integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable designs designed to perform the functions described herein may be used. Logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof, implement or perform the various illustrative logic, logic blocks, modules, and circuits described in connection with the disclosed examples. A general purpose processor may be a microprocessor, but in an alternative embodiment, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more of a DSP core, or any other such configuration.

The steps or processes of the methods or algorithms described in connection with the examples disclosed herein may be directly implemented in a hardware, a software module executed by a processor, or a combination of both. The software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, scratchpad, hard disk, removable disk, CD-ROM or known in the art. Any other form of storage media. An exemplary storage medium can be coupled to the processor such that the processor can read information from the storage medium and write the information to the storage medium. In an alternate embodiment, the storage medium can be integrated into the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In an alternate embodiment, the processor and the storage medium may reside as discrete components in the user terminal.

The description of the disclosed examples is provided to enable any person skilled in the art to make or use the presently disclosed methods and apparatus. Various modifications to the disclosed examples can be readily appreciated by those skilled in the art, and the general principles defined herein may be applied to other examples without departing from the spirit or scope of the disclosure (eg, in Instant messaging service or any general wireless data communication application). Therefore, the present disclosure is not intended to be limited to the examples shown herein, but should be accorded to the broadest scope of the principles and novel features disclosed herein. The word "exemplary" is used exclusively in this article to mean

"Use as an example, example or description." Any example described herein as "exemplary" is not necessarily to be construed as preferred or advantageous.

Accordingly, while an example of a communication system having a transmitter identification has been illustrated and described herein, it will be appreciated that various changes may be made to the examples without departing from the spirit or essential characteristics thereof.

Novel method 1

‧TxID or other parameters are signaled in the PPC packet

‧With an 80-bit PPC packet

Slide 1

Novel method 2: splitting parameters across PPC symbols

‧TxID or other parameters are signaled in the PPC packet

‧With a 56-bit PPC packet

Slide 2

Novel Method 2: Encoding

‧ Longer payload by reducing duplication and increasing the number of code blocks from 4 to 8

‧R-M code is identical to QC design

Slide 3

Note: Novel Method 2 (56-bit packet)

+ Only code block & repeat number change, R-M code is the same

+The performance of the current embodiment is not degraded

+ For implementation/testing, the two options are simple with a single package size

+ Packet type makes it self-contained and allows for scalability to include other parameters such as transmitter power and number of frames

Slide 4

Novel Method 3: Use PPC to retain state

‧PPC retention status is intended to be a transmitter specific channel

‧Slot 7 is not assigned because it is used by a non-active transmitter

‧ Assign the remaining slots to the pilot or data and use WID/LID to disrupt

‧ WID/LID for available transmitters from identification status

‧Show two possible slot assignments for pilot/data

1.2 pilot slots (and 3 data slots), the channel estimation is the same as in the identification status

2. Increase the data slot to 5, and the path location information from the recognition state is combined with only 2 pilot slots.

Slide 5

Novel Method 3: Encoding

‧Use 3 or 5 data slots to allow reuse of turbo coding structures from data and OIS channels

‧When using 3 data slots, use QPSK R 1/3 (modulo 0) to send a physical layer packet (PLP)

‧When using 5 data slots, use QPSK R 1/5 (modulo 5) to send a PLP

Slide 6

Method 3: Packet Format

‧ Large payload that can be used to send transmitter IDs and other parameters

‧The sample format can be as shown below

Slide 7

Note: Novel Method 3 (976 bit packet)

+ Large packet size provides great flexibility in defining the packet format

+ can send other parameters, such as transmitter power & number of frames

+ can also send the location of adjacent transmitters and other parameters

+ Multiple symbols can be used in a hyperframe or can define multiple packet types and send the multiple packet types across the hyperframe to further increase the payload size

+ can also avoid sending locations only by not assigning transmitter-specific channels in the recognition state

+The same encoding/decoding structure as the data/OIS channel

Slide 8

100. . . Communication network

102. . . Wide area

104. . . Wide area

106. . . Local area

108. . . Local area

110. . . Local area

112. . . Transmitter

114. . . Transmitter

116. . . Transmitter

118. . . Mobile device

120. . . Mobile device

122. . . Transmitter

124. . . Transmitter

126. . . Transmitter

128. . . Device

130. . . Device

132. . . Transmitter

134. . . Transmitter

136. . . Transmitter

138. . . Device

140. . . Device

142. . . arrow

144. . . arrow

146. . . arrow

200. . . Communication Systems

202. . . Pilot positioning channel

204. . . Wireless link

206. . . Receiving device

208. . . Transmitter logic

210. . . PPC generator logic

212. . . Network logic

214. . . Transmitter step

216. . . Receiver logic

218. . . PPC decoder logic

220. . . Transmitter ID decision logic

221. . . Location decision logic

222. . . Receiving device

224. . . Network supply information

226. . . system time

234. . . PPC symbol

236. . . PPC symbol

238. . . PPC symbol

300. . . Transmission hyperframe

302. . . Preamble information

304. . . Data frame

400. . . OFDM symbol/active PPC symbol

402. . . Interlaced I ₀

404. . . Interlaced I ₂

406. . . Interlaced I ₄

408. . . Interlaced I ₆

410. . . Interlaced I ₁

412. . . Interlaced I ₃

414. . . Interlaced I ₅

416. . . Interlaced I ₇

500. . . Inactive PPC symbol

502. . . Interlaced I ₇

600. . . Means for encoding transmitter identification in interleaving of PPC symbols in action (such as the interlacing illustrated in Figure 4)

602. . . Module for setting or determining a transmitter identifier (TxID) bit and assigning a bit

604. . . Module for adding CRC bits to TxID bits and allocating bits

606. . . Interleaver

608. . . Encoder

610. . . Encoder

612. . . Zero insertion module

614. . . Repeater

616. . . Scrambler

618. . . Modulator

620. . . Interleaver

700. . . Hardware circuit

702. . . Input

704. . . counter

706. . . Multiplier

708. . . Block

710. . . Summation block

900. . . Device for transmitting PPC symbols with transmitter identification information

902. . . Module configured to receive network provisioning data (eg, transmission status information)

904. . . Module for encoding pilot information on a first portion of a plurality of subcarriers in a symbol of one of the active transmitters using a seed WID

906. . . Membrane for encoding transmitter identification information on another portion of the first portion of the plurality of subcarriers of the symbol using the WID and LID seed

908. . . According to a predetermined coding scheme module information in a second portion of the plurality of subcarriers (e.g., subcarriers in interlace ₃ in the I) up identification code transmission (the TxID)

910. . . Module configured to transmit PPC symbols

912. . . Module

914. . . Memory device

1100. . . Device for use in a receiver in a system with transmitter identification information

1102. . . Module for receiving at least one PPC symbol and determining energy in one or more interlaces

1104. . . Communication bus

1106. . . Module for determining WID seeds from a predetermined interleaving (eg, interleaving I ₁ )

1108. . . Module for determining LID from a predetermined interleave (eg, interlaced I ₀ ) using WID

1110. . . Module for determining a channel estimate for self-acting interleaving (eg, interleaving I ₀ , I ₂ , I _{4 ,} and I ₆ )

1112. . . Module for decoding dedicated interlaces (eg, I ₃ ) to determine transmitter identification information (TxID)

1114. . . Module for determining transmitter identification code based on TxID (and receiving device positioning based on transmitter ID, channel estimation and energy measurement)

1116. . . processor

1118. . . Memory device

T1-T5. . . Transmitter

Figure 1 illustrates a communication network that can be used with the disclosed transmitter identification scheme;

2 illustrates an example of a communication system characterized by transmission of transmitter identification information;

Figure 3 shows a transmission hyperframe that can be used in the system of Figure 1 or Figure 2;

4 shows a functional diagram of an interleaved structure of OFDM symbols for PPC symbols transmitted by an active transmitter;

5 shows a functional diagram of an interleaved structure of OFDM symbols for PPC symbols transmitted by a passive or inactive transmitter;

Figure 6 illustrates means for encoding transmitter identification in interleaving of PPC symbols in effect, such as the interlacing illustrated in Figure 4;

Figure 7 illustrates an exemplary hardware circuit that can be used to generate an RM code in a transmitter;

8 shows a method for providing transmitter identification in a wireless system, such as the system illustrated in FIGS. 1 and 2.

Figure 9 illustrates an apparatus for transmitting PPC symbols having transmitter identification information;

10 shows a method for receiving a symbol including transmitter identification information; and

Figure 11 shows another example of a receiver device or alternatively a device for use in a receiver in a system having transmitter identification information.

200. . . Communication Systems

202. . . Pilot positioning channel

204. . . Wireless link

206. . . Receiving device

208. . . Transmitter logic

210. . . PPC generator logic

212. . . Network logic

214. . . Transmitter block/transmitter

216. . . Receiver logic

218. . . PPC decoder logic

220. . . Transmitter ID decision logic

221. . . Location decision logic

222. . . Receiving device

224. . . Network supply information

226. . . system time

234. . . PPC symbol

236. . . PPC symbol

238. . . symbol

T1-T5. . . Transmitter

Claims (43)

A method for using a Pilot Channel for Positioning (PPC) to convey transmitter identification in an interlaced structure of a communication network system, the method comprising: a) locating a pilot channel for one of the transmitters in operation Precoding the pilot information on a first portion of the plurality of subcarriers in the symbol; and b) explicitly encoding the self-contained transmitter identification information on a dedicated second portion of the plurality of subcarriers of the symbol; wherein the plurality of The first portion of the subcarrier includes at least first and second interlaces, and the second portion of the plurality of subcarriers includes at least one third interlace; and the pilot information is identified by a wide area in the first interlace The symbol is disturbed and is scrambled by the wide area identifier and a local area identifier in the at least second interlace. The method of claim 1, wherein the transmitter identification information is exclusively encoded in the at least third interlace. The method of claim 2, wherein the interlaced structure is grouped into eight interlaces. The method of claim 3, wherein the dedicated second portion of the plurality of subcarriers comprises the transmitter identification information in the form of one or more transmitter position coordinates in an idle interlace. The method of claim 4, wherein the transmitter position coordinates comprise longitude, latitude, or altitude coordinates. The method of claim 5, wherein the at least third interlace also includes network delay information. The method of claim 6, wherein the transmitter identifies the information at a length of 80 One of the bits of the fixed bit PPC packet is signaled, and the fixed bit PPC packet includes 10 blocks of 8 bits each. The method of claim 7, wherein the 80-bit PPC packet is assigned the following options: The method of claim 7, wherein the 80-bit PPC packet is assigned the following options: The method of claim 1, wherein the transmitter identification information comprises an allocation field configured to communicate that one or more subsequent symbols are assigned to a transmitter specific channel for communicating further information. The method of claim 10, further comprising transmitting information about the particular application via the transmitter specific channel. The method of claim 1, wherein the encoding of the transmitter identification information comprises: interleaving the information bits of the transmitter identification information; Encoding the bits using a predetermined coding scheme; manipulating the coded bits to ensure that the number of bits matches a predetermined modulation scheme; modulating the bits according to the predetermined modulation scheme; and The modulated bit is mapped to a subcarrier in the second portion of the plurality of subcarriers of the symbol. The method of claim 12, wherein the predetermined coding scheme comprises a Reed-Muller code. The method of claim 12, wherein manipulating the encoded bits comprises culling one or more encoded bits and replacing the culled encoded bits with a zero value. The method of claim 12, wherein the predetermined modulation scheme comprises QPSK modulation. The method of claim 1, wherein the communication system comprises an OFDM communication system. A device for communicating transmitter identification in a staggered configuration in a communication network system using a positioning pilot channel (PPC), the device comprising: a) a first module configured to One of the transmitters is operative to encode pilot information on a first portion of the plurality of subcarriers in the pilot channel symbol; and b) a second module configured to have a plurality of subcarriers at the symbol One of the dedicated second parts explicitly encodes the self-contained transmitter identification information; The first portion of the plurality of subcarriers includes at least first and second interlaces, and the second portion of the plurality of subcarriers includes at least one third interlace; and the pilot information is used in the first interlace A wide area identifier is used to scramble and the wide area identifier and a local area identifier are used to scramble in the at least second interlace. The apparatus of claim 17, wherein the dedicated second portion of the plurality of subcarriers comprises the transmitter identification information in the form of one or more transmitter position coordinates in an idle interlace. The apparatus of claim 17, wherein the interleaved structure is grouped into eight interlaces. The device of claim 18, wherein the transmitter location coordinates comprise longitude, latitude, or altitude coordinates. The device of claim 20, wherein the at least third interlace also includes network delay information. The apparatus of claim 21, wherein the transmitter identification information is signaled within a fixed bit PPC packet having a length of 80 bits, the fixed bit PPC packet comprising 10 blocks of 8 bits each. The device of claim 22, wherein the 80-bit PPC packet is allocated as follows . The device of claim 22, wherein the 80-bit PPC packet is assigned the following options: A computer program product comprising: a computer readable medium, comprising: encoding a pilot on a first portion of a plurality of subcarriers in a pilot channel symbol for positioning a computer in an active transmitter a code of information; and a code for causing a computer to explicitly encode the identification information of the self-contained transmitter on a dedicated second portion of the plurality of subcarriers of the symbol; wherein the first portion of the plurality of subcarriers Including at least first and second interlaces, and the second portion of the plurality of subcarriers includes at least one third interlace; the pilot information includes means for causing a computer to perform a wide area identifier in the first interlace a scrambled code and a code for causing a computer to scramble with the wide area identifier and a local area identifier in the at least second interlace; and wherein the dedicated second part of the plurality of subcarriers comprises For causing a computer to encode one or more transmitter position coordinates in an idle interlace The code in the form of the transmitter identifying the information. The computer program product of claim 25, wherein the transmitter identification information is exclusively encoded in the at least third interlace. The computer program product of claim 25, wherein the transmitter identification information comprises at least one of a transmitter identification field, a transmitter allocation field, and a cyclic redundancy check bit. The computer product of claim 27, wherein the transmitter allocation field is configured to communicate whether a subsequent symbol including further material is to be transmitted. The computer program product of claim 25, wherein the computer readable medium further comprises code for causing a computer to transmit a transmitter allocation data within the transmitter identification information, the allocation data indicating assignment of one or more subsequent symbols Give a transmitter specific channel for further information. The computer program product of claim 25, wherein the computer readable medium further comprises: a code for interleaving the information bits of the transmitter identification information; a program for encoding the bits using a predetermined encoding scheme a code for manipulating the encoded bits to ensure that the number of bits matches a predetermined modulation scheme; a code for modulating the bits according to the predetermined modulation scheme; The isomorphic bit maps to the code of the subcarrier in the second portion of the plurality of subcarriers of the symbol. The computer program product of claim 30, wherein the predetermined encoding scheme comprises a Reed-Muller code. The computer program product of claim 30, wherein the code for manipulating the encoded bits further comprises a program for culling one or more encoded bits and replacing the culled coding bits with a zero value code. The computer program product of claim 30, wherein the predetermined modulation scheme comprises a QPSK modulation. The computer program product of claim 25, wherein the active transmitter comprises an active transmitter in an OFDM communication system. A computer readable medium embodying a method for communicating transmitter identification in a staggered structure in a communication network system using a positioning pilot channel (PPC), the method comprising: a) an active transmitter One of the plurality of subcarriers in the positioning pilot channel symbol encodes pilot information on a first portion; and b) explicitly encodes the self-contained transmitter on a dedicated second portion of one of the plurality of subcarriers of the symbol Identifying information; wherein the first portion of the plurality of subcarriers includes at least first and second interlaces, and the second portion of the plurality of subcarriers includes at least one third interlace; and the pilot information is in the first interlace The medium is scrambled with a wide area identifier and is scrambled by the wide area identifier and a local area identifier in the at least second interlace. The computer readable medium of claim 35, wherein the transmitter identification information is exclusively encoded in the at least third interlace. The computer readable medium of claim 35, wherein the interlaced structure is grouped into eight interlaces. The computer readable medium of claim 37, wherein the dedicated second portion of the plurality of subcarriers comprises the transmitter identification information in the form of one or more transmitter position coordinates in an idle interlace. The computer readable medium of claim 38, wherein the transmitter location coordinates comprise longitude, latitude, or altitude coordinates. The computer readable medium of claim 39, wherein the at least third interlace also includes network delay information. The computer readable medium of claim 40, wherein the transmitter identification information is signaled in a fixed bit PPC packet having a length of 80 bits, the fixed bit PPC packet comprising 10 respective 8 bits. Block. The computer readable medium of claim 35, wherein the transmitter identification information is exclusively encoded on the dedicated second portion of the plurality of subcarriers. The computer readable medium of claim 41, wherein the 80 bit PPC packet is assigned the following options: