CN1898887B - Local and wide-area transmissions in a wireless broadcast network - Google Patents

Abstract

To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

Description

Local in the wireless broadcast network and wide-area transmission

The application requires to enjoy U.S. Provisional Application No.60/514 that submit to, that be entitled as " Method forTransmitting Local and Wide-Area Content over a Wireless MulticastNetwork " on October 24th, 2003,152 priority.

Technical field

The present invention relates generally to communication, relate in particular to the transfer of data in the cordless communication network.

Background technology

In order to provide miscellaneous service to large quantities of users, widespread deployment wireless and wired broadcasting network.Common wired broadcasting network is the cable network that transmits content of multimedia to a large amount of families.Usually, cable network comprises front end and distribution node.Each front end is from various information source program receivings, is that each program produces independent modulation signal, the modulation signal of all programs is multiplexed on the output signal, and its output signal is sent to described distribution node.Each program can be a wide geographic area (as, whole state) or less geographic area (as, city) in distribute.In wide geographic area, each specific zone of distribution node covering (as, a community).Each distribution node termination is in the past received output signal, and the modulation signal of the program that will distribute in its overlay area is multiplexed on the different channels, then, its output signal is sent to family in its overlay area.Usually, the output signal of each distribution node carries (national) of the overall situation and the program of this locality simultaneously, and these programs are everlasting to be multiplexed on the modulation signal on the described output signal and are sent.

Wireless broadcast network sends data with wireless mode to the wireless device that is positioned at this network's coverage area.Wireless broadcast network is different in several importances and cable network.At first, in wireless broadcast network, if the signal that different base station sends is inequality, then these signals can interfere with each other.By contrast, the output signal of each distribution node sends on private cable, therefore, can not be subjected to the interference of other nodes.The second, each base station in the wireless broadcast network is launched injection modulation signal frequently usually, and described signal carries the data of all programs of its base station broadcast.By contrast, each distribution node in the wired broadcasting network can be multiplexed into different programs modulation signal separately on the different frequency range.Because these differences are used for not being suitable for wireless broadcast network usually in the technology of wired broadcasting network distribution program.

Therefore, need a kind of wireless broadcast network that plurality of kinds of contents with distinct coverage region can be broadcasted in this area.

Summary of the invention

The application disclose be used for the dissimilar transmission of wireless broadcast network broadcasting (as, local and wide-area transmission) technology.In this article, " broadcasting " refers in one group of user of any size sends perhaps data, also can be called as " multicast " or other terms.Wide-area transmission is meant can be by the transmission of whole in this network or most of transmitter broadcasts.The local transmission is meant can be by the transmission of a transmitter subclass broadcasting that is used for given wide-area transmission.Different local transmission can be by the different transmitters subclass broadcasting that is used for given wide-area transmission.Different wide-area transmission also can be broadcasted by emission units different in the described network.One of given transmitter subclass who is used for the transmission of given local can broadcast field domain (venue) transmission than smaller subset.Wide-area transmission, local transmission and field domain transmission can be regarded the dissimilar transmission with different coverings time (tiers) as, and wherein the overlay area of every kind of transmission is by all transmitter decisions of this transmission of broadcasting.Different contents is carried in wide area, local and place transmission usually, but these transmission also can be carried identical content.

In each base station of wireless broadcast network (or, transmitter) in, wide area transmission data is to handle according to first coding and the modulation scheme (or " pattern ") selected for this wide-area transmission, thereby generates the data symbol of this wide-area transmission.The data that are used for the local transmission are to handle according to second coding and the modulation scheme selected for this local transmission, thereby generate the data symbol of this local transmission.At described wide area and local transmission, first and second coding and modulation scheme can be selected based on the expectation coverage of this base station respectively.Generation is used to recover the Time Division Multiplexing frequency pilot sign and/or frequency division multiplexing (FDM) frequency pilot sign of local and wide-area transmission.Equally, also determine Overhead, described Overhead indicates the time and/or the frequency location of each data channel that sends in local and wide-area transmission.Data channel is carried at content of multimedia and/or other data that send in local and the wide-area transmission.

The data of local and wide-area transmission, frequency pilot sign and Overhead can be undertaken multiplexing by variety of way.For example, the data symbol of wide-area transmission can be multiplexed on " transmission span (span) " that distributes to this wide-area transmission, the data symbol of local transmission is multiplexed on the transmission span of distributing to this local transmission, the TDM and/or the FDM frequency pilot sign of wide-area transmission are multiplexed on the transmission span of distributing to these frequency pilot signs, and TDM and/or FDM frequency pilot sign that local is transmitted are multiplexed on the transmission span of distributing to these frequency pilot signs.The Overhead of local and wide-area transmission can be multiplexed on one or more given transmission spans.Different transmission spans can be corresponding to the set of (1) different frequency subband, if described wireless broadcast network uses FDM; (2) different time period is if use TDM; Or (3) be positioned at the different sub-band group of different time sections, if use FDM and TDM simultaneously.Various multiplex modes are below described.The two or more dissimilar transmission that also can handle, multiplexing and broadcasting has two or more different coverings time.

Wireless device in the wireless broadcast network is carried out complementary the processing, thereby recovers local and wide area transmission data.Various aspects of the present invention and embodiment are described below in further detail.

Description of drawings

By the detailed description below in conjunction with accompanying drawing, it is more apparent that characteristic of the present invention and essence will become, and in institute's drawings attached, identical mark is represented identical parts, wherein:

Fig. 1 shows wireless broadcast network;

Fig. 2 A shows the overlay area of wide-area transmission;

Fig. 2 B shows the overlay area of different local transmission;

Fig. 3 A shows the FDM structure that is used to broadcast local and wide-area transmission;

Fig. 3 B shows the broadcast transmitted of the FDM structure of utilizing among Fig. 3 A;

Fig. 4 A shows the TDM structure that is used to broadcast local and wide-area transmission;

Fig. 4 B shows the broadcast transmitted of the TDM structure of utilizing among Fig. 4 A;

Fig. 5 shows the structure of the super frame that is used to broadcast local and wide-area transmission;

Fig. 6 shows data subband is divided in three disjoint subsets;

Fig. 7 shows the TDM frequency pilot sign of local and wide-area transmission;

Fig. 8 shows the process of broadcasting local and wide-area transmission;

Fig. 9 shows the process that receives local and wide-area transmission; And

Figure 10 shows the block diagram of base station and wireless device.

Embodiment

" exemplary " used herein speech means " as example, illustration or explanation ".Here being described to any embodiment of " exemplary " or design should not be interpreted as than other embodiment or design more preferably or have more advantage.

Fig. 1 shows wireless broadcast network 100, and described network can be broadcasted dissimilar transmission, as, wide-area transmission and local transmission.Can broadcast each wide-area transmission by a collection of base stations in the described network, this collection of base stations can comprise in the described network all or most base station.Usually, each wide-area transmission of broadcasting in a big geographic area.A subclass that is used for the given collection of base stations of given wide-area transmission is broadcasted each local transmission.Usually, each local transmission of broadcasting in a less geographic area.For the sake of simplicity, the big geographic area of wide-area transmission is also referred to as broad overlay area or abbreviates " wide area " as, and the less geographic area of local transmission is also referred to as local coverage area or abbreviates " local " as.Network 100 can have broad overlay area, as one of the whole U.S., the U.S. big zone (as, western state), whole state etc.For example, an independent wide-area transmission can be broadcasted in whole California, and the transmission of different locals can be broadcasted in different cities, as Los Angeles and Santiago.

For the sake of simplicity, Fig. 1 shows network 100, and it has covered wide area 110a and 110b, and wherein wide area 110a comprises three local 120a, 120b and 120c.Usually, network 100 can comprise a wide area and any the local with different locals transmission with different wide-area transmission arbitrarily.Each local can be adjacent with another local, maybe can isolate.Network 100 also can be broadcasted any dissimilar transmission, and described transmission is specified in arbitrarily and receives in the different big or small geographic area.For example, network 100 can be broadcasted the field domain transmission, and described transmission is specified in the less geographic area and receives, and described zone can be the part of given local.For the sake of simplicity, in following most of the description,, suppose that network 100 covers an independent wide area and a plurality of local for two kinds of different transport-types.

Fig. 2 A shows the wide-area transmission overlay area in the network 100.The identical wide-area transmission of all base station broadcasts in the given wide area is so this network is called as unifrequency network (SFN).If the identical wide-area transmission of all base station broadcasts in this wide area, so, wireless device can improve performance in conjunction with the signal of receiving from different base stations.On physical layer, the major defect of Data Receiving is thermal noise and decreased performance among the SFN, this be owing to wireless channel the time become and excessive deferral is expanded (delay spread) and caused.Postponing expansion is arriving signal example (or multipath) and the time difference between the arriving signal example the earliest the latest at the wireless device place.

Fig. 2 B shows the distinct coverage region of different local transmission in the network 100.Base station in the different locals sends different local transmission, so this network is called as multi-frequency network (MFN)." SFN " and " MFN " is the broadcasting term, be generally used for describing network characteristic, and MFN might not mean that different base station transmits on different radio frequency.Although the local transmission that the base station broadcast in the different locals is different,, the wireless device in the given local may can be subjected to the interference of base station in the adjacent local hardly, because its distance to base station, interference side is longer relatively.For the wireless device of these inside, the local transmission has the character of SFN in essence.

Wireless device near the local edge may observe tangible adjacent local channel disturbance (ALCI), and this is that signal by base station in the adjacent local causes.For example, wireless device 2 in the local A may be experienced the obvious ALCI from adjacent local B and C, wireless device 3 in the local B may be experienced from adjacent local A and the tangible ALCI of C, and the wireless device 5 in the local C may be experienced the obvious ALCI from adjacent local A and B.For these peripheral wireless devices, network is MFN in nature substantially.For SFN, ALCI causes extra decreased performance.For SFN and MFN, if data are handled in the same way and transmitted, so, under the MFN situation, the ALCI that ancillary equipment observes has reduced the signal quality that these wireless devices receive, and has reduced the coverage of adjacent local boundary.

Usually, every kind of transport-type (as, wide area and local) coverage can be complementary with the user demand of this kind transport-type.Have more extensive adaptive transmission and can send to wireless device in the bigger geographic area.On the contrary, have more limited adaptive transmission and can send to wireless device in the less geographic area.

Can planned network 100 provide good performance for local and wide-area transmission simultaneously.This can obtain by carrying out following several method:

■ carries out local and wide-area transmission multiplexing in time domain, frequency domain and/or sign indicating number territory, thereby reduces by two kinds of interference between the transport-type;

■ launches local and wide-area transmission (also having their corresponding frequency pilot signs) respectively based on the heterogeneity of MFN and SFN; And

■ provides flexibility aspect resource allocation, thereby satisfies multiple (source) rate requirement of local and wide-area transmission.

Based on the character of MFN, send the local transmission, thereby provide better covering for the wireless device that is positioned at this local edge.Boundary between different wide areas, its wide-area transmission also is MFN in nature, and, also can use technology described herein to send.More than three aspects will be discussed in more detail below respectively.

1. local and wide-area transmission is multiplexing

Fig. 3 A shows FDM structure 300, and it is used in the multicarrier network by given system bandwidth broadcasting local and wide-area transmission.By be tuned to the receiver of single radio frequency, FDM structure 300 is supported the reception of local and wide-area transmission simultaneously, and is different from the scheme of using different radio frequency to send local and wide-area transmission.By multi-carrier modulation technology, as OFDM (OFDM) or other technologies, the whole system bandwidth is divided into the frequency band of several (N) quadratures.These subbands are also referred to as voiced band, carrier wave, subcarrier, frequency band and frequency channels.Utilize OFDM, each subband is associated with separately subcarrier, described subcarrier data available is modulated.In N subband altogether, U subband can be used for the transmission of data and pilot signal, so be called as " available " subband, wherein U≤N.Remaining G subband is not used and is called as " protection " subband, wherein W=U+G.In a concrete example, network can use a kind of OFDM structure, and described structure has N=4096 subband, a U=4000 available subband and G=96 protection subband altogether.Usually, N, G and U can be arbitrary values.For the sake of simplicity, following description supposes that all N subband all can be used for transmission, i.e. U=N and G=0, thus do not protect subband.

In each symbol period of transfer of data, P subband in the individual available subband of N can be used for the FDM frequency pilot sign, so be called as " pilot tone " subband, wherein P＜N.Frequency pilot sign is made up of known modulation symbol usually, and it is handled and send with a kind of known mode.D available subband of residue can be used for transfer of data, so be called as " data " subband, wherein D=N-P.The TDM frequency pilot sign also can send by all N available subbands in some symbol period.

For embodiment as shown in Figure 3A, the FDM frequency pilot sign sends on P pilot subbands, and these subbands are distributed in the whole system bandwidth, thereby better spectral sample is provided.Can be with this D data allocation of subbands to local transmission, wide-area transmission, Overhead etc.Can be with L _SbThe local transmission is distributed in a set of individual subband, with W _SbWide-area transmission is distributed in a set of individual subband, wherein W _Sb+ L _Sb≤ D.As shown in Figure 3A, the W that is used for wide-area transmission _SbIndividual subband and the L that is used for the local transmission _SbIndividual subband can be distributed in the whole system bandwidth, improves frequency diversity.W _SbIndividual subband carries the data (or abbreviating wide-area data as) of wide-area transmission, and L _SbIndividual subband carries the data (or abbreviating local area data as) of local transmission.

Fig. 3 B shows the different local area data transmission that utilize FDM structure 300.In order to reduce the interference between local and the wide-area transmission, W can be used in all interior base stations of given wide area _SbThe incompatible broadcasting wide-area transmission of the same set of individual subband.Base station in the different locals can be transmitted in different locals the L that distributes to these local transmission _SbBroadcast in the set of individual subband.Based on resource requirement, can change into the number of sub-bands that local and wide-area transmission are distributed.For example, W _SbAnd L _SbCan followingly change: (1) dynamically changes from the symbol to the symbol or from the time slot to the time slot; (2) based on the time of every day, weekly the sky etc.; (3) based on predefined pattern; (4) based on the combination in any of above condition.For example, W _SbAnd L _SbCan in a period of time of every workday, dynamically change, immobilize, be provided with based on preassigned pattern at weekend in the remaining time of every workday.

In order to simplify resource allocation and to improve frequency diversity, this N available subband can be arranged as M " interlace (interlace) " or disjoint sets of subbands.Non-intersect being embodied in of this M interlace, each in the individual available subband of this N only belongs to an interlace.Each interlace comprises P available subband, wherein N=MP.The P of each an interlace subband can be evenly distributed in N the available subband, and like this, the continuous subband of each interlace is separated by M subband.For exemplary OFDM structure described above, can form M=8 interlace, each interlace comprises P=512 available subband, and these available subbands are kept apart equably by 8 subbands.Thus, the P of the P of each interlace available subband and other a M-1 interlace available subband is staggered.

An exemplary OFDM structure and an interlace scheme has more than been described.Other OFDM structures and allocation of subbands scheme also can be used for supporting the FDM of local and wide-area transmission.

Fig. 4 A shows TDM structure 400, and it also is used in broadcasting local and wide-area transmission in single carrier and the multicarrier network.The transmitting time axle is divided into several frames 410, and each frame all has predetermined perdurabgility.Frame duration can be selected based on multiple factor, as, the time diversity amount that transfer of data is required.Each frame comprises: field 412 is used to carry frequency pilot sign and Overhead; Section 414 is used to carry wide-area data; Section 416 is used to carry local area data.Each frame also can comprise other fields that are used for other information.

Fig. 4 B shows the different local area data transmission that utilize TDM structure 400.In order to reduce the interference between local and the wide-area transmission, the wide area section 414 that is used for all base stations in the given wide area can be carried out time alignment, so that make these base stations can broadcast wide-area transmission simultaneously.Different local transmission can be broadcasted in base station in the different locals in section 416. Section 414 and 416 can dynamically change, or changes according to predetermined way based on resource requirement.

For the TDM structure 400 shown in the FDM structure 300 shown in Fig. 3 A and Fig. 4 A, local and wide-area transmission respectively frequency and carry out on the time multiplexing so that minimize overlapping between these two kinds of transport-types.Two kinds of interference between the transport-type are avoided and minimized to this aligning (alignment).But, do not need to strictly observe the not overlapping of different transport-types.In addition, different locals can have different frequencies or time to distribute.Usually, can use multiple multiplexing structure, broadcasting has the dissimilar transmission of distinct coverage region.A concrete multiplexing structure is described below, and it is applicable to the wireless broadcast network based on OFDM.

Fig. 5 shows exemplary super frame structure 500, and it can be used to broadcasting local and wide-area transmission in based on the wireless broadcast network of OFDM.Transfer of data is that unit takes place with super frame 510.Each super frame is crossed over predetermined time duration, and the described duration can be selected based on multiple factor, as, be broadcasted the required time diversity amount of expection statistic multiplexing, the data flow of data flow, the acquisition time of data flow, the buffer requirement of wireless device etc.The super frame of about one second size can obtain compromise between above-mentioned multiple factor.Yet, also can use other super frame size.

For the embodiment shown in Fig. 5, each super frame 510 comprises frame 530a to 530d and end segment 540 of 520,4 identical sizes of a head sections, and these sections do not show in Fig. 5 in proportion.Table 1 has been enumerated the section of being used for 520 and 540 and the various field that is used for each frame 530.

Table 1

Field	Describe
		The TDM frequency pilot sign	The TDM frequency pilot sign is used for input, frame synchronization, frequency error estimation and time synchronized.
The transition pilot symbol	This frequency pilot sign is used for channel estimating and possible time synchronized, and sends at the boundary of wide area and local fields/transmissions.
		WIC	Wide area sign channel (WIC)-the carry identifier of distributing to the wide area of serving.
LIC	Local sign channel (WIC)-the carry identifier of distributing to the local of serving.
		Wide area OIS	The Overhead of wide area overhead information symbol (OIS)-be carried at each data channel that sends in the wide-area data field (as, frequency/time location and distribution).
Local OIS	Local OIS-is carried at the Overhead of each data channel that sends in local data's field.
		Wide-area data	Carry the data channel that is used for wide-area transmission
Local area data	Carry the data channel that is used for the local transmission

For the embodiment shown in Fig. 5, different frequency pilot signs is used for different purposes.The TDM frequency pilot sign is to be positioned at or the original position that approaches each super frame sends, and can be used for the purposes shown in the table 1.The transition pilot symbol is to send at the boundary of wide area and local fields/transmissions, realizes the seamless transitions of wide area and local fields/transmissions, and method generates as described below.

Local and wide-area transmission can be used for content of multimedia, as video, audio frequency, teletext, data, video/audio clip etc., and send in different data flow.For example, multimedia (as, TV) program can be respectively applied for video at three, sends in the different data streams of audio frequency and data.Data flow sends on data channel.The one or more data flow of each data channel portability.The data channel that carries local area transmission data stream is also referred to as " local channel ", and the data channel that carries wide area transmission data stream is also referred to as " wide-area channel ".In super frame, the local channel sends in the local area data field, and wide-area channel sends in the wide-area data field.

In each super frame, can be the interlace of the fixing or variable number of each data channel " distribution ", this depends on the availability of interlace in the load, super frame of this data channel and other possible factors.In any given super frame, each data channel can be activity or inactive.Also can be concrete interlace in each active data channels " distribution " super frame according to a kind of allocative decision, this allocative decision is attempted: (1) is as far as possible efficiently with all active data channels packages; (2) reduce transmission time of each data channel; (3) provide the time enough diversity for each data channel; (4) signaling amount that will be used to refer to the interlace of distributing to each data channel minimizes.For each movable data channel, 4 frames of super frame can use identical interlace allocative decision.

Local OIS indicates the time/Frequency Distribution of each movable local channel of current super frame automatically.Wide area OIS field is represented the time/Frequency Distribution of each active wide-area channel of current super frame.Original position in each super frame sends local OIS and wide area OIS, so that wireless device can be determined the T/F position of each associated data channel in the super frame.

Various field in the super frame can send in proper order by as shown in Figure 5 order or other.Usually, in super frame, preferably send TDM frequency pilot sign and Overhead as early as possible, so that can use TDM frequency pilot sign and Overhead to be received in the data that send after a while in this super frame.Wide-area transmission can send before the local transmission, as Fig. 4 A and shown in Figure 5, perhaps sent after the local transmission.

Fig. 5 shows a concrete super frame structure.Usually, super frame can be crossed over the duration arbitrarily, also can comprise section, frame and the field of any amount and any type.Yet,, have the useful scope of a super frame duration usually according to the acquisition time and the circulation timei of receiver electronic device.Also can utilize other super frame and frame structure to broadcast dissimilar transmission, but this also fall into protection scope of the present invention.

As shown in Figure 5, by local and wide-area transmission are carried out time division multiplexing, wide-area transmission can be enjoyed the advantage of OFDM under the SFN situation, and is not subjected to the interference of local transmission.Owing to only send local or wide-area transmission with TDM at any given time, therefore, local and wide-area transmission can utilize can independent optimization different transmission parameter broadcast, thereby, obtain the superperformance of local and wide-area transmission respectively, as described below.

2. transfer of data

Can be with the wide-area channel broadcasted in each super frame package as far as possible efficiently.In four wide-area data territories of each super frame, the identical wide-area transmission of all base station broadcasts in the given wide area.Wireless device can make up the wide-area transmission of receiving from any a plurality of base stations, improves the performance of Data Receiving.

Different local transmission can be broadcasted in base station in the different locals in four local area data territories of each super frame.The peripheral wireless device that is positioned at adjacent local boundary vicinity will observe adjacent local channel disturbance (ALCI), and this interference has reduced the quality of described equipment place received signal.The quality of received signal can quantize by signal and noise plus interference ratio (SINR) or other standard of measurement values.Because the influence that ALCI causes, peripheral wireless device will obtain lower SINR.At the place, base station, a kind of coding and modulation scheme are adopted in the processing of local area transmission data, and this scheme needs specific SINR to reach correct reception.Owing to there is ALCI, given wireless device can reach required SINR in less zone, and therefore, ACLI has the effect of reduction local.

Can use multiple technologies to improve the coverage of local transmission.Usually, for the coverage at extended boundary place, these Technology Needs are made some sacrifices at the aspect of performance of local inside.These technology comprise that part loads (partial loading) and coded/modulated is selected.

Utilize part to load (being also referred to as frequency reuse), in fact not all available subband that can be used for transfer of data all is used to transmit data.In addition, can be adjacent local allocated subbands, so that their local transmission is interfered with each other as few as possible.This can load by quadrature component loading or random partial and realize.

Utilize quadrature component to load, can be adjacent local and distribute non-intersect or nonoverlapping sets of subbands.Next, broadcasting local transmission on the sets of subbands of this local is being distributed in the base station in each local.Because sets of subbands is non-intersect, the wireless device in each local can not observe the ALCI from base station in the adjacent local.

It is S to label that Fig. 6 shows exemplary D the data subband of cutting apart ₁, S ₂, S ₃Three disjoint subclass in.Usually, each set can comprise any a plurality of data subband and can comprise in this D the data subband any one.The subband of each set also dynamically or according to preassigned pattern changes.In order to realize frequency diversity, each set can comprise the subband of choosing out from whole D data subbands.Subband in each set can be evenly or is distributed in unevenly in whole D the data subbands.

Get back among Fig. 2 B, can be with sets of subbands S ₁Distribute to local A, can be with sets of subbands S ₂Distribute to local B, and, can be with sets of subbands S ₃Distribute to local C.So the base station in the local A is at sets of subbands S ₁The local transmission of last broadcasting local A, the base station in the local B is at sets of subbands S ₂The local transmission of last broadcasting local B, the base station in the local C is at sets of subbands S ₃The local transmission of last broadcasting local C.

Fig. 2 B and Fig. 6 show the situation of three locals.Quadrature component loads can expand to any a plurality of local.For Q adjacent local, can form Q disjoint sets of subbands, wherein Q＞1.This Q set can comprise the subband of identical or different number.For above-mentioned interlace scheme, M-1 the available interlace that is used for transfer of data can be distributed to this Q set.Each set can comprise any a plurality of interlace.Each intersection of sets wrong fount can dynamically or based on preassigned pattern change.For each local distributes corresponding interlace set, to be used for the local transmission.Can in whole network, carry out frequency planning, to guarantee distributing disjoint set for adjacent local.

The employing random partial loads, and is that each local distributes K data subband, K≤D wherein, and the base station in this local is broadcasted corresponding local and is transmitted on K subband with the pseudo-random fashion selection from D data subband.For each local, in each symbol period, can use Pseudo-random number generator to select a different sets with K subband.Different locals can use different PN makers, so that the subband that each local uses is pseudorandom with respect to the subband that its adjacent local uses.In fact, the transmission of the local of each local is crossed over D data subband and is jumped.When conflict takes place and when adjacent local uses identical subband in same symbol period, will observe ALCI.Yet, because in each symbol period, the K of each a local subband is selected with pseudo-random fashion, so ALCI has been randomized.Wireless device is known the jump that carry out the base station, recovers this local transmission so carry out the complementary jumping (de-hoping) of separating.

Load for random partial, along with the reduction of K, collision probability and ALCI amount also decrease.But for given coding and modulation scheme, K is more little, and total throughout is just low more.Therefore, the selection of K can be based on trading off between overlay area and the total throughout.

Load for the part of any type, under the situation that does not increase total transmitting power, can increase the transmitting power of each subband that is used to carry out transfer of data.Total transmitting power can be distributed in K subband that is used for carrying out the local transmission in each symbol period, so be also referred to as " activity " subband.If K subband is used for the local transmission and D subband is used for wide-area transmission, K＜D under the part load condition wherein, so, the transmitting power of each movable subband that local transmits is than wide-area transmission height.Therefore, use part to load, the quality of the received signal of each active channels is higher, this just improved the receiver virgin with signal to noise ratio.

For having only data subband, have only pilot subbands or comprising data and pilot subbands simultaneously, can carry out quadrature and random partial and load.To reduce total throughout is cost, and quadrature and random partial load can improve coverage.This be because, under the situation that part loads, the subband that is used for transfer of data is few more, the information bit that sends in each symbol period of these less subbands is also just few more thereupon.Based on trading off between coverage that increases and the total throughout, select to be used to carry out the number of sub-bands of local transmission.

Network can be supported multiple transmission mode, or abbreviation " pattern ".Every kind of pattern is corresponding to specific encoding scheme or code rate, specific modulation scheme, specific spectrum efficiency and specific minimum required SINR, so that reach the performance rate of an appointment, as, concerning non-decline awgn channel, be 1% packet error probability (PER).Spectrum efficiency can be that the unit is represented by the information bit in each modulation symbol, and determines based on code rate and modulating mode.Usually, the pattern that has than low frequency spectrum efficient needs lower SINR.For each pattern, can obtain required SINR based on concrete system design (as code check, interleaving scheme and be used for the modulation scheme of this pattern) and specific channel general status.Required SINR can determine by computer simulation, experience measurement etc.

By selecting to be used for the appropriate mode of local transmission, can adjust the overlay area of this local transmission.Pattern with low SINR demand can be used for the local transmission, thereby expansion is in the coverage of adjacent local boundary vicinity.The AD HOC that is used for the local transmission can be selected based on trading off between coverage and the spectrum efficiency.Similarly, by selecting to be used for the appropriate mode of wide-area transmission, also can adjust the coverage of this wide-area transmission.Usually, local and wide-area transmission can adopt identical or different pattern.

The coverage of local transmission can improve by part loading and/or model selection.Have pattern by utilizing than low frequency spectrum efficient than the available subband of small scale and/or selection, can extended coverage range.Information bit rate (R) can be expressed as: R=η * K, and wherein η is the spectrum efficiency of institute's lectotype, K is the number of movable subband.Obtaining of given information bit rate can be by using: a subclass of (1) all data subbands and have the pattern of high spectral efficiency; Perhaps (2) all data subbands and have pattern than low frequency spectrum efficient.For specific operation scene (load and do not have an Interference Estimation) as, random partial, compare with option one, option 2 can provide more performance (as, for the wideer coverage of given PER).

3. pilot transmission

Fig. 7 shows pilot transmission schemes, and it can support local and wide-area transmission simultaneously.For the sake of simplicity, Fig. 7 shows the pilot transmission of a frame in the super frame.Each base station sends the transition pilot symbol between local and wide-area fields/transmissions.In each symbol period of transfer of data, each base station also sends the FDM frequency pilot sign on an interlace.For embodiment as shown in Figure 7, in each symbol period, 8 available interlace are arranged, and, in the even-numbered symbol period, on interlace 3, send the FDM frequency pilot sign, in the odd-numbered symbol period, on interlace 7, send the FDM frequency pilot sign, this can be expressed as 3, the 7} interleaving mode.Also available other interleaving modes of FDM frequency pilot sign send, as 1,2,3,4,5,6,7, the 8} pattern and 1,4,7,2,5,8,3, the 6} pattern.

As shown in Figure 7, the FDM frequency pilot sign not only sends during wide-area transmission, and sends between the local transmission period.The FDM frequency pilot sign can be used for obtaining: the channel estimating of (1) wide-area transmission is also referred to as wide-area channel and estimates; (2) the local channel transmitted is estimated, is also referred to as the local channel estimating.The channel estimating of local and wide-area transmission can be respectively applied for the Data Detection and the decoding of local and wide-area transmission.

The FDM frequency pilot sign that sends during wide-area transmission is called as wide area FDM frequency pilot sign, its design can be used for making things convenient for wide-area channel to estimate.In whole wide area, can send identical wide area FDM frequency pilot sign.The FDM frequency pilot sign that sends between the local transmission period is called as local FDM frequency pilot sign, its design can be used for making things convenient for the local channel estimating.In different locals, can send different local FDM frequency pilot signs, so that wireless device can obtain to be used for the local channel estimating of different locals.At the boundary of adjacent local, different local FDM frequency pilot signs interfere with each other, and this point is similar to the ALCI of different local transmission.Can design local FDM frequency pilot sign, so that under the situation that exists adjacent local frequency pilot sign to disturb, can obtain good local channel estimating.This can carry out orthogonalization in frequency domain, time domain and/or sign indicating number territory by the local FDM frequency pilot sign with different locals or randomization realizes, and is as described below.

Fig. 7 also shows the embodiment of local FDM frequency pilot sign.For this local FDM frequency pilot sign, the set of P modulation symbol is used for P pilot subbands.P modulation symbol can multiply by the first complex values sequence and/or multiply by the second complex values sequence in the time in frequency, thereby generated the frequency pilot sign of this local FDM pilot tone.First sequence table is shown { S (K) }, and wherein S (K) is the complex values of subband K.Second sequence table is shown { C (n) }, and wherein C (n) is the complex values of symbol period n.By using the first and second dissimilar sequences, can obtain the different qualities of local FDM pilot tone.

The PN maker can be used to generate the first complex values sequence.The PN maker can be a linear feedback shift register (LFSR), and it has realized a selectivity generator polynomial, as, g (x)=x ¹⁵+ x ¹⁴+ 1.When each symbol period begins, this PN maker is initialized as a specific seed (or, initial condition), and generates PRBS pseudo-random bit sequence.These bits are used for forming the complex values of first sequence.

For the local FDM pilot tone of a given local, its frequency pilot sign can be expressed as:

P (k, n)=S (k) C (n), formula (1)

Wherein, P (k, n) frequency pilot sign of subband k among the is-symbol cycle n.Formula (1) supposes that the modulation symbol that is used for described local FDM pilot tone has value 1+j0.

The frequency pilot sign that wireless device receives can be expressed as:

Y (k, n)=H (k, n) P (k, n)+H _I(k, n) P _IW (k, n)+w (k, n), formula (2)

Wherein, (k n) is the frequency pilot sign that is sent by a base station that is positioned at the expection local (that is expection base station) to P on subband k in symbol period n;

(k n) is the real channel response of expection base station to H;

H _I(k is by a frequency pilot sign that interference base station sends on subband k in symbol period n in the adjacent local n);

(k n) is the frequency pilot sign of the subband k that receives to Y in symbol period n; And

(k n) is the noise of subband k in symbol period n to w.For the sake of simplicity, formula (2) supposes to exist an expection base station and an interference base station subscript of representing with subscript I.

By sending local FDM pilot tone in different symbol periods and/or subband, these FDM pilot tones that are used for different locals are orthogonalization on time and/or frequency respectively.But for the local FDM pilot tone of each local sends less frequency pilot sign, therefore, less patterns available symbol can be used for the local channel estimating.

Can be with the local FDM pilot tone that is used for different locals in sign indicating number territory orthogonalization and/or randomization, this can be by using different quadratures and/or pseudo random sequence to realize respectively to these locals FDM pilot tone.For local FDM pilot tone, can use various orthogonalization/randomized techniques, comprise quadrature scrambling, scrambling and quadrature and scrambling at random at random.

For the quadrature scrambling, the local FDM pilot tone that is used for different locals multiply by the interior orthogonal sequence of symbol period.Therefore, the frequency pilot sign of expection and interference local can followingly be represented:

P (k, n)=S (k) C (n) and P _I(k, n)=S (k) C _I(n), formula (3)

Wherein { C (n) } and { C _I(n) } quadrature.As shown in Equation (3), use identical PN sequence to come for expecting and disturbing local to generate the first complex values sequence { S (k) }.Yet,, use different orthogonal sequence { C (n) } and { C for expection and interference local _I(n) }.

The complex channel gain of each pilot subbands by at first obtaining to be used for local FDM pilot tone estimates that wireless device can obtain the local channel estimating, and is as follows:

${\hat{H}}_p\left(k\right)=P(k,n)/S\left(k\right).$ Formula (4)

Formula (4) has been eliminated the influence of PN sequence in whole pilot subbands, this is also referred to as descrambling.Wireless device obtains P evenly P channel gain estimation of distribution pilot subbands.Next, wireless device is estimated to carry out P point discrete Fourier inverse transformation (IDFT) to P channel gain, obtains P tap least square impulse response and estimates, can be expressed as:

${\hat{h}}_{\mathrm{os}}(l,n)=h\left(l\right)\·C\left(n\right)+h_I\left(l\right)\·C_I\left(n\right)+w(l,n),$ Formula (5)

Wherein l is the label of the individual channel tap of P ' of impulse response estimation;

H (l) is the actual impulse response of expection base station;

h _I(l) be the actual impulse response of interference base station; Be that the least square impulse response of symbol period n is estimated, wherein subscript " os " expression quadrature scrambling; And

W (l, n) noise among the is-symbol cycle n.

Formula (5) supposes that in the relevant duration, the actual channel impulse response of each base station remains unchanged, so h (l) and h _I(l) function of is-symbol cycle n not.

Then, the impulse response of expection local is estimated

Can estimate to obtain by the least square impulse response that filters the distinct symbols cycle, as follows:

${\tilde{h}}_{\mathrm{os}}\left(l\right)=\frac{1}{L}\·\underset{n=-(L-1)/2}{\overset{(L-1)/2}{\mathrm{\Σ}}}{\hat{h}}_{\mathrm{os}}(l,n)\·C\left(n\right),$

$=\frac{1}{L}\·\underset{n=-(L-1)/2}{\overset{(L-1)/2}{\mathrm{\Σ}}}h\left(l\right)\·C\left(n\right)\·C^{*}\left(n\right)+h_I\left(l\right)\·C_I\left(n\right)\·C^{*}\left(n\right)+w(l,n)\·C^{*}\left(n\right),$

$h\left(l\right)+\tilde{w}(l,n),$ Formula (6)

Wherein $\underset{n=-(L-1)/2}{\overset{(L-1)/2}{\mathrm{\Σ}}}{C}_I\left(n\right)\·C^{*}\left(n\right)=0,$ This is because C (n) and C _I(n) be orthogonal sequence;

It is noise through reprocessing; And

L be orthogonal sequence length (as, L=3).

Summation index (index of summation) is an odd number value corresponding to L in the formula (6), and is then different when L is even number value.Be positioned at the wireless device that disturbs local, by inciting somebody to action

With C _I ^*(n) multiply each other and carry out integration in the length of orthogonal sequence, the impulse response that obtains this local is estimated As shown in Equation (6), the quadrature scrambling can be eliminated the Pilot Interference that adjacent local causes.But, becoming during owing to channel, this orthogonality can multilated.

Orthogonal sequence can define with multiple mode.In one embodiment, orthogonal sequence is as giving a definition:

C (n)=1 and C _I(n)=e ^{J2 π n/L}, n=0 wherein ... (L-1).Formula (7)

For scrambling at random, the frequency pilot sign of expection local is pseudorandom with the frequency pilot sign that disturbs local relatively.Can think, frequency pilot sign in time, frequency and local be independent identically distributed (i, i, d).By come the PN maker of the different locals of initialization with different seeds, can obtain the pseudorandom frequency pilot sign, wherein seed depends on the identifier of symbol period n and this local.

For scrambling at random, obtain the least square impulse response and estimate Can realize by carrying out the following step: (1) is descrambling as shown in formula (4), to remove the PN sequence of this expection local; (2) reprocessing is estimated to obtain P channel gain; (3) the P channel gain is estimated to carry out IDFT, as mentioned above.The least square impulse response is estimated and can be expressed as:

${\hat{h}}_{\mathrm{rs}}\left(l\right)=h\left(l\right)+g_I(l,n)+w(l,n),$ Formula (8)

Wherein, g _I(l is right n)

The interference of l tap, subscript " rs " is represented scrambling at random.Disturb g _I(l is because the channel impulse response h of this interference local n) _I(l) existed by the PN sequence of this local and interference local P tap scope in smear (smeared) and produce.The least square impulse response is estimated and can directly be estimated as the impulse response of expection local.Formula (8) shows, at random scrambling (rather than suppress or the eliminate) Pilot Interference that adjacent local caused of only erasing.Can carry out thresholding operation (thresholding), thereby, the channel tap that surpasses predetermined threshold kept, the channel tap that will be lower than predetermined threshold make zero (zeroout).The performance that can eliminate most Pilot Interference and provide of operating thresholding approaches the performance by quadrature scrambling acquisition.In addition, use scrambling at random, channel estimating performance does not rely on orthogonality, so more healthy and stronger under some operational environment.

For quadrature and scrambling at random, the local FDM pilot tone of different locals multiply by PN sequences different on several subbands, also multiply by orthogonal sequences different on several symbol periods then.The frequency pilot sign of expection and interference local can followingly be represented:

P (k, n)=S (k) C (n) and P _I(k, n)=S _I(k) C _I(n) formula (9)

Wherein { S (k) } is different pseudo random sequences with { SI (k) }, { C (n) } and { C _I(n) } be different orthogonal sequences.

For quadrature and scrambling at random, the least square impulse response is estimated

Can be by carrying out

Above-mentioned quadrature scrambling is handled and is obtained.The least square impulse response is estimated also can be expressed as:

${\hat{h}}_{\mathrm{or}}(l,n)=h\left(l\right)\·C\left(n\right)+g_I\left(l\right)\·C_I\left(n\right)+w(l,n),$ Formula (10)

Wherein, subscript " or " expression quadrature and scrambling at random.The impulse response of expection local is estimated

Can pass through will

Multiply by C ^*(n) and in the length integrates of orthogonal sequence and obtain, as shown in Equation (6).

The sample channel impulse response in each zone (wide area or local) comprises N tap, wherein N=MP at most.Channel impulse response can be regarded as by a main channel and an extra channel and form.Main channel comprises preceding P tap of channel impulse response.Extra channel comprises a remaining N-P tap.If the FDM pilot tone sends having on the interlace of P subband, the impulse response that then has P tap is estimated

Or Can obtain based on the FDM pilot tone of receiving.Usually, the length of impulse response estimation is determined by the quantity of the different sub-band that is used for the FDM pilot tone.Have estimating and to obtain by on more interlace, sending the FDM pilot tone more than P tap than the long channel impulse response.For example, the FDM pilot tone can send on two different interlace of distinct symbols in the cycle, as shown in Figure 7.Submit on August 25th, 2004, exercise question is the patent application No.10/926 of " Staggered Pilot Transmission for ChannelEstimation and Time Tracking ", described the technology of obtaining main channel and extra channel time domain filtering coefficient in 884.

For local and wide area, can obtain different channel estimating.Wireless device can be from base station received signal, described base station with respect to wide-area transmission than local long transmission distance.Therefore, the delay of wide-area transmission expansion is longer than the delay expansion of local transmission.For wide area, can obtain long channel impulse response estimation (as, length is 3P).For local, can obtain short channel impulse response estimation (as, length is 2P).

Wide area FDM pilot tone is used more interlace, then can obtain long impulse response and estimate.Perhaps, the FDM pilot tone of local and wide area also can be used the interlace of similar number, and local can use different time domain filterings with wide area.The least square impulse response of wide area is estimated to filter by first set of one or more time domain filterings, estimates with impulse response after the filtration that obtains this wide area, and it has expected numbers purpose tap (as, 3P tap).The least square impulse response of expection local is estimated to filter by second set of time domain filtering, and with impulse response estimation after the filtration that obtains this expection local, it has expected numbers purpose tap (as, 2P tap).

Usually, the time domain of channel estimating is filtered and can be carried out based on multiple consideration, as, the send mode of FDM pilot tone, be used for the required length (or number of taps) of interlace number, the channel impulse response estimation of FDM pilot tone, disturb and suppress etc.For local and wide area, can carry out time domain to the FDM pilot tone by different modes and filter, thereby be that channel response is estimated after the local filtration different with the wide area acquisition.

For given area (local or wide area), the impulse response after the filtration is estimated and can further be improved performance by reprocessing.Reprocessing can comprise, as: with last Z tap zero setting, wherein Z can be any integer value; Energy is lower than the tap zero setting (thresholding operation) of predetermined threshold etc.Channel tap through reprocessing can be carried out conversion with DFT, estimates so that obtain final frequency response, is used for Data Detection and decoding.

Get back among Fig. 5, transition pilot can be used for channel estimating, time synchronized, obtains (as, automatic gain control (AGC)) etc.For example, transition pilot can comprise the FDM pilot tone, thereby, for each symbol period, can to the current sign cycle, at least one early the reception frequency pilot sign that obtains in the symbol period late of symbol period and at least one carry out time domain and filter.Transition pilot can be used to improve the sequential of local transmission and wide-area transmission.

4. broadcast transmitted and reception

Fig. 8 shows the flow chart of process 800, and this process is used in network 100 broadcasting local and wide-area transmission.Each base station in this network can be in each scheduling interval implementation 800, described scheduling interval may be each super frame of super frame structure 500 among each frame of TDM structure 400 in each symbol period, Fig. 4 A of FDM structure 300 among Fig. 3 A or Fig. 5.

According to the data of handling wide-area transmission for first coding and the modulation scheme (or pattern) of wide-area transmission selection, to generate the data symbol (frame 812) of wide-area transmission.Handle the data that local transmits according to second coding and the modulation scheme (or pattern) selected for the local transmission, to generate the data symbol (frame 814) of local transmission.Can use different coding and modulation schemes to reach the expection coverage to local and wide-area transmission.Determine the Overhead (frame 816 and frame 818) of local and wide-area transmission.Generate wide area FDM pilot tone, local FDM pilot tone and transition pilot (respectively in frame 822, frame 824 and frame 826).

The Overhead of the Overhead of wide-area transmission and local transmission is multiplexing on the transmission span of its appointment (frame 832 and frame 834).The data symbol of wide-area transmission is multiplexing on the transmission span that distributes for this wide-area transmission (frame 836), and the frequency pilot sign of this wide area FDM pilot tone is multiplexing on the transmission span that is this pilot frequency distribution (frame 838).Similarly, the data symbol of local transmission is multiplexing on the transmission span that distributes for this local transmission (frame 840), and the frequency pilot sign of this local FDM pilot tone is multiplexing on the transmission span that is this pilot frequency distribution (frame 842).Each transmission span can corresponding to one group of subband (as, for FDM structure 300), time period (as, for TDM structure 400), one group of subband in time period (as, for super frame structure 500) or other times-Frequency Distribution.Also can multiplexing TDM and transition pilot, other signalings and other data (frame 844).Then, the local behind the broadcasting multiplex and wide-area transmission Overhead, pilot tone and data.

Fig. 9 shows the flow chart of process 900, and this process is used to receive the local and the wide-area transmission of network 100 broadcasting.In each scheduling interval, the wireless device in the network can implementation 900.

Wireless device is received broadcast transmitted, comprises local and wide-area transmission (frame 912).Described wireless device processes TDM pilot tone is to obtain (frames 914) such as frame and symbol sequential, estimation and correction of frequency errors.Described wireless device identifies wide area and the local channel (frame 916) that uses WIC and LIC service respectively.After this, described wireless device can recover local transmission, wide-area transmission or local and wide-area transmission from the broadcast transmitted of receiving.

If judge that in frame 920 described wireless device is receiving wide-area transmission, so, this wireless device carries out demultiplexing and processing to the Overhead of this wide-area transmission, to determine the T/F position (frame 922) of each relevant wide-area channel.Described wireless device also can be with these pilot tone demultiplexings and processing (frame 924) from the transmission span of distributing to this wide area FDM and transition pilot, and obtains the channel estimation value (frame 926) of this wide-area transmission.Described wireless device is demultiplexing go out the to be correlated with data symbol (frame 928) of wide-area channel from the transmission span of distributing to this wide-area transmission also.Next, this wireless device utilizes wide-area channel to estimate, and further according to the demodulation code plan that is applicable to this wide-area transmission, handles the data symbol of wide-area transmission, and, recover the data (frame 930) of relevant wide-area channel.

Receiving the local transmission if judge described wireless device in frame 940, so, the Overhead of this local transmission of this wireless device demultiplexing and processing is to determine the T/F position (frame 942) of each relevant local channel.Described wireless device also can be from the transmission span of distributing to this local FDM and transition pilot carries out these pilot tones demultiplexing and processing (frame 944), and obtains expection local channel transmitted estimated value (frame 946).Described wireless device demultiplexing from the transmission span of distributing to local transmission go out to be correlated with data symbol (frame 948) of local channel.Next, this wireless device utilizes the local channel estimating and further according to the demodulation code plan that is applicable to local transmission, handles the data symbol of local transmission, and, recover the data (frame 950) of each relevant local channel.

If wireless device receives local and wide-area transmission at the same time, so, this wireless device can be carried out processing procedure according to the order shown in a kind of Fig. 9 of being different from.For example, when receiving the Overhead of local and wide-area transmission, this wireless device can demultiplexing and this Overhead of processing.

5. system

The block diagram of Figure 10 shows base station 1010 and the wireless device 1050 that is arranged in Fig. 1 wireless broadcast network 100.Usually, base station 1010 is fixed stations, is also referred to as access point, transmitter or other terms.Wireless device 1050 can be a portable unit, as cell phone, handheld device, wireless module, PDA(Personal Digital Assistant) etc.

In base station 1010, send (TX) data processor 1022 and receive the data of wide-area transmission from information source 1012, handle (as, decode, interweave and sign map) this wide-area data, and generate the data symbol of this wide-area transmission.Data symbol is a modulation symbols for data, and, modulation symbol be a kind of modulation scheme (as, M-PSK, M-QAM etc.) signal graph (signalconstellation) in any complex values.TX data processor 1022 also generates the FDM and the transition pilot of base station 1010 place wide areas, and the data and the frequency pilot sign of this wide area offered multiplexer 1026.Send (TX) data processor 1024 and receive the data that local transmits, handle this local area data, and generate the data symbol of this local transmission from information source 1014.TX data processor 1024 also generates the FDM and the transition pilot of base station 1010 place locals, and the data and the frequency pilot sign of this local offered multiplexer 1026.The coding of data and modulation can be selected based on multiple factor, are expection coverages etc. of wide-area transmission or local area transmission data, data type, data as these data.

Multiplexer 1026 is multiplexed into the data of local and wide area and the symbol of frequency pilot sign and Overhead and TDM pilot tone on the subband and symbol period of distributing to these symbols.Modulator (Mod) 1028 carries out modulation according to the modulation technique that network 100 uses.For example, the symbol after 1028 pairs of modulators are multiplexing is carried out the OFDM modulation, generates the OFDM symbol.The symbol of transmitter unit (TMTR) 1032 devices of automodulation in the future 1028 is converted into one or more analog signals, further finishing (as, amplification, filtration and up-conversion) described analog symbol, to generate modulation signal.Then, base station 1010 sends it to wireless device the described network from antenna 1034.

In wireless device 1050, the transmission signal that antenna 1052 receives from base station 1010, and provide it to receiver unit (RCVR) 1054.Receiver unit 1054 finishing (as, filtration, amplification and down-conversion) signal received, carry out digitlization with trimmed data, to generate data sampling stream.Demodulator (Demod) 1060 is carried out (as OFDM) demodulation to these data samplings, and the frequency pilot sign of receiving is offered (Sync)/channel estimating unit 1080 synchronously.Unit 1080 also receives data sampling from receiver unit 1054, determines frame and symbol sequential based on these data samplings, and based on local of receiving and wide area frequency pilot sign, obtains its channel estimating.Unit 1080 offers demodulator 1060 with this symbol sequential and channel estimating, and the frame sequential is offered demodulator 1060 and/or controller 1090.Demodulator 1060 utilizes the local channel estimating, the local area transmission data symbol of receiving is carried out Data Detection, utilize wide-area channel to estimate, the wide area transmission data symbol of receiving is carried out Data Detection, and the detection data of local and wide-area transmission are offered demodulation multiplexer (Demux) 1062.The detection data symbol is the estimation by the data symbol of base station 1010 transmissions, and can represent by log-likelihood ratio (LLR) or other modes.

Demodulation multiplexer 1062 offers reception (RX) data processor 1072 with the detection data symbol of all relevant wide-area channel, and the detection data symbol of all relevant local channels is offered RX data processor 1074.RX data processor 1072 is according to the demodulation code plan that is suitable for, handle (as, deinterleaving and decoding) the detection data symbol of wide-area transmission, and data after the decoding of this wide-area transmission are provided.RX data processor 1074 is handled the detection data symbol of this local transmission according to the demodulation code plan that is suitable for, and offers data after the decoding of this local transmission.Usually, the demodulator 1060 of wireless device 1050, demodulation multiplexer 1062 and RX data processor 1072 are complementary mutually with modulator 1028, multiplexer 1026 and the TX data processor 1022 and 1024 of base station 1010 respectively with 1074 processor.

The operation of controller 1040 and 1090 difference management of base station 1010 and wireless device 1050.The program and the data of memory cell 1042 and 1092 difference storage controls 1040 and 1090.The broadcasting of 1044 pairs of locals of scheduler and wide-area transmission is dispatched and is that different transport-types distributes and assign resources.

For clarity sake, Figure 10 shows the data handling procedure of local and wide-area transmission, and described processing procedure is carried out by two different pieces of information processors in base station 1010 and the wireless device 1050.The data processing of all transport-types can be carried out by the individual data processor that is in one of base station 1010 and wireless device 1050.Figure 10 also shows the processing procedure of two kinds of dissimilar transmission.Usually, a plurality of dissimilar transmission with distinct coverage region can be sent by base station 1010 arbitrarily, and are received by wireless device 1050.For clarity sake, Figure 10 also shows all unit of the base station 1010 that is distributed in same site.Usually, these unit can be distributed in identical or different website, and can communicate by multiple communication link.For example, data source 1012 and 1014 also can be positioned at outside the website, and transmitter unit 1032 and/or antenna 1034 also can be positioned at emission website etc.

With respect to the traditional scheme of the dissimilar transmission of broadcasting on different RF channels, multiplexing scheme described herein (as, in Fig. 3 A, 4A and 5) have a lot of advantages.At first, multiplexing scheme described herein can provide more frequency diversity than traditional multiplexing scheme, and this is because every type transmission sends on the whole system bandwidth, rather than sends on single RF channel.The second, multiplexing scheme described herein make receiver unit 1054 can use be tuned to the single RF unit of single RF frequency receive and all types of transmission of demodulation.This has simplified the design of wireless device.By contrast, traditional scheme needs a plurality of RF unit to recover the dissimilar transmission that sends on the different RF channel.

The technology that is used for broadcasting dissimilar transmission aloft described herein can realize in several ways.For example, these technology can realize with hardware, software or way of hardware and software combination.Realize for hardware, be used for being used for other electronic units or its combination that processing unit in the dissimilar transmission of base station broadcasting can be implemented in one or more application-specific integrated circuit (ASIC)s (ASIC), digital signal processor (DSP), digital signal processor spare (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, is used for carrying out function described herein in the base station.Be used for also can be implemented among one or more ASIC, the DSP etc. at the processing unit of the dissimilar transmission of wireless device reception.

Realize that for software technology described herein can realize with the module (for example, process, function etc.) of carrying out function described herein.These software codes can be stored in the memory cell (as, the memory cell 1042 or 1092 among Figure 10), and are carried out by processor (as controller 1040 or 1090).Memory cell can be implemented in the processor or outside the processor, under latter event, it can be connected to processor communicatedly via various means well known in the art.

Here the subtitle that comprises is used for reference and helps the specific part of definition.These do not limit the protection range of its notion that describes below, and these notions can be applicable in other parts of whole specification.

The foregoing description of described disclosed embodiment can make those skilled in the art can realize or use the present invention.To those skilled in the art, the various modifications of these embodiment are conspicuous, and the general principles of definition here also can be applied to other embodiment without departing from the spirit and scope of the present invention.Therefore, the present invention is not limited to embodiment given here, but consistent with the widest scope that meets principle disclosed herein and novel feature.

Claims (54)

1. method that is used at the wireless broadcast network broadcast data comprises:

To first transmission span, described wide-area transmission is that a plurality of transmitters from described network send with the data multiplex of wide-area transmission;

To second transmission span, described local transmission is that a subclass from described a plurality of transmitters sends with the data multiplex of local transmission; And

Broadcast described local and wide-area transmission by Radio Link;

Wherein, described wireless broadcast network utilizes OFDM (OFDM);

Wherein, the data of the data of described wide-area transmission and the transmission of described local are Time Division Multiplexing, wherein, described first transmission span comprises all frequency subbands that carry out transfer of data in the very first time section that is used in a frame, and wherein, described second transmission span comprises all frequency subbands that carry out transfer of data in second time period that is used in described frame.

2. the transmission of the method for claim 1, wherein different local is that the different subclass from described a plurality of transmitters send.

3. the method for claim 1, wherein different wide-area transmission is to send from different a plurality of transmitters.

4. the method for claim 1 also comprises:

On data multiplex to the three transmission spans with field domain transmission, described field domain transmission be from one of the described subclass of described a plurality of transmitters more smaller subset send.

5. the data multiplex that the method for claim 1, wherein described local is transmitted disturbs to reduce to being less than on all usable frequency subbands.

6. method as claimed in claim 5, wherein, will from the data multiplex of the described local transmission of the described subclass of described a plurality of transmitters to the used frequency subband of at least one other subclass of described a plurality of transmitters mutually on the frequency subband of quadrature.

7. method as claimed in claim 5, wherein, with the data multiplex of described local transmission to the frequency subband of from all usable frequency subbands, selecting with pseudo-random fashion.

8. the method for claim 1 also comprises:

According to first coding and the modulation scheme, handle the data of described wide-area transmission, wherein, with the data multiplex of the described wide-area transmission after handling to described first transmission span; And

According to second coding and the modulation scheme, handle the data of described local transmission, wherein, with the data multiplex of the described local transmission after handling to described second transmission span.

9. method as claimed in claim 8 wherein, based on the expection coverage of described wide area and local transmission, is selected described first and second coding and the modulation scheme respectively.

10. method as claimed in claim 8, wherein, described second coding is compared with modulation scheme with described first coding with modulation scheme, has lower spectrum efficiency, thereby expands the coverage of described local transmission.

11. method as claimed in claim 8, wherein, described first coding is compared with modulation scheme with described second coding with modulation scheme, has lower spectrum efficiency.

12. the method for claim 1 also comprises:

Based on the transmission and the data type of the data that wherein send the transmission of described wide area and local, processing said data.

13. the method for claim 1 also comprises:

First frequency pilot sign is multiplexed on the 3rd transmission span, and described first frequency pilot sign is suitable for obtaining first channel estimating of described wide-area transmission; And

Second frequency pilot sign is multiplexed on the 4th transmission span, and described second frequency pilot sign is suitable for obtaining the second channel estimation of described local transmission.

14. method as claimed in claim 13 wherein, in different symbol periods, is multiplexed into described first and second frequency pilot signs in the different frequency sub-bands set separately.

15. the method for claim 1 also comprises:

First frequency pilot sign is multiplexed into the different frequency sub-bands set that is used for carrying out in the distinct symbols cycle of the described very first time section pilot symbol transmission, and described first frequency pilot sign is suitable for obtaining first channel estimating of described wide-area transmission; And

Second frequency pilot sign is multiplexed into the different frequency sub-bands set that is used for carrying out in the distinct symbols cycle of described second time period pilot symbol transmission, and described second frequency pilot sign is suitable for obtaining the second channel estimation of described local transmission.

16. method as claimed in claim 13 also comprises:

Orthogonal sequence with the described subclass of distributing to described a plurality of transmitters, generate described second frequency pilot sign, wherein, at least one other second frequency pilot sign of described second frequency pilot sign of the described subclass of described a plurality of transmitters and at least one other subclass of described a plurality of transmitters quadrature mutually.

17. method as claimed in claim 13 also comprises:

Pseudo random sequence with the described subclass of distributing to described a plurality of transmitters, generate described second frequency pilot sign, wherein, described second frequency pilot sign of the described subclass of described a plurality of transmitters is pseudorandom with respect at least one other second frequency pilot sign of at least one other subclass of described a plurality of transmitters.

18. method as claimed in claim 13 also comprises:

Multiply by the modulation symbol of different frequency sub-bands with the pseudo random sequence of the described subclass of distributing to described a plurality of transmitters, to obtain the convergent-divergent symbol, wherein, described pseudo random sequence is used for each symbol period; And

Multiply by the described convergent-divergent symbol in distinct symbols cycle with the orthogonal sequence of the described subclass of distributing to described a plurality of transmitters, to generate described second frequency pilot sign, wherein, described second frequency pilot sign of the described subclass of described a plurality of transmitters is pseudorandom on frequency and is quadrature in time with respect at least one other second frequency pilot sign of at least one other subclass of described a plurality of transmitters.

19. the method for claim 1 also comprises:

The Overhead of described wide-area transmission is multiplexed on the 3rd transmission span; And

The Overhead of described local transmission is multiplexed on the 4th transmission span.

20. method as claimed in claim 19, wherein, the Overhead of described wide-area transmission indicates the frequency and the time location of each data channel of described wide-area transmission, and wherein, the Overhead of described local transmission indicates the frequency and the time location of each data channel of described local transmission.

21. the method for claim 1 also comprises:

Based on the amount of broadcast data of described wide-area transmission and the amount of broadcast data of described local transmission, select described first and second transmission spans.

22. the method for claim 1 also comprises:

Based on the time of every day, adjust described first and second transmission spans.

23. the method for claim 1 also comprises:

Based on predetermined dispatch list, adjust described first and second transmission spans.

24. a kind of device in the wireless broadcast network comprises:

Multiplexer, be used to receive the data of wide-area transmission and it is multiplexed into first transmission span, and, receive the data of local transmission and it is multiplexed on second transmission span, described wide-area transmission is that a plurality of transmitters from described network send, and the transmission of described local is that a subclass from described a plurality of transmitters sends; And

Transmitter unit is used for broadcasting described local and wide-area transmission by Radio Link;

Wherein, described wireless broadcast network utilizes OFDM (OFDM), wherein, the data of the data of described wide-area transmission and the transmission of described local are Time Division Multiplexing, wherein, described first transmission span comprises all frequency subbands that carry out transfer of data in the very first time section that is used in a frame, and wherein, described second transmission span comprises all frequency subbands that carry out transfer of data in second time period that is used in described frame.

25. device as claimed in claim 24 also comprises:

First data processor is used for handling the data of described wide-area transmission according to first coding and modulation scheme; And

Second data processor is used for handling the data that described local transmits according to second coding and modulation scheme; And

Wherein, the data multiplex of the described wide-area transmission after described multiplexer will be handled is to described first transmission span, and the data multiplex of the described local transmission after will handling is to described second transmission span.

26. device as claimed in claim 25, wherein, described first data processor also generates first frequency pilot sign, described first frequency pilot sign is suitable for obtaining first channel estimating of described wide-area transmission, wherein, described second data processor also generates second frequency pilot sign, described second frequency pilot sign is suitable for obtaining the second channel estimation of described local transmission, and wherein, described multiplexer also is multiplexed into described first frequency pilot sign on the 3rd transmission span and with described second frequency pilot sign and is multiplexed on the 4th transmission span.

27. device as claimed in claim 24, wherein, described multiplexer also is multiplexed into the Overhead of described wide-area transmission on the 3rd transmission span, and the Overhead that described local is transmitted is multiplexed on the 4th transmission span.

28. device as claimed in claim 24 also comprises:

Controller based on the amount of broadcast data of described wide-area transmission and the amount of broadcast data of described local transmission, is selected described first and second transmission spans.

29. a kind of device in the wireless broadcast network comprises:

The wide area transmission data Multiplexing module is used for data multiplex with wide-area transmission to first transmission span, and described wide-area transmission is that a plurality of transmitters from described network send;

The local area transmission data Multiplexing module is used for data multiplex with local transmission to second transmission span, and described local transmission is that a subclass from described a plurality of transmitters sends; And

Broadcast module is used for by the described local behind the Radio Link broadcasting multiplex and the data of wide-area transmission;

Wherein, described wireless broadcast network utilizes OFDM (OFDM), wherein, the data of the data of described wide-area transmission and the transmission of described local are Time Division Multiplexing, wherein, described first transmission span comprises all frequency subbands that carry out transfer of data in first time period that is used in a frame, and wherein, described second transmission span comprises all frequency subbands that carry out transfer of data in second time period that is used in described frame.

30. device as claimed in claim 29 also comprises:

The wide area transmission data processing module is used for handling the data of described wide-area transmission according to first coding and the modulation scheme, wherein, with the data multiplex of the described wide-area transmission after handling to described first transmission span; And

The local area transmission data processing module is used for handling the data of described local transmission according to second coding and the modulation scheme, wherein, with the data multiplex of the described local transmission after handling to described second transmission span.

31. device as claimed in claim 29 also comprises:

The first frequency pilot sign Multiplexing module is used for first frequency pilot sign is multiplexed into the 3rd transmission span, and described first frequency pilot sign is suitable for obtaining first channel estimating of described wide-area transmission; And

The second frequency pilot sign Multiplexing module is used for second frequency pilot sign is multiplexed into the 4th transmission span, and described second frequency pilot sign is suitable for obtaining the second channel estimation of described local transmission.

32. device as claimed in claim 29 also comprises:

Wide-area transmission Overhead Multiplexing module is used for the Overhead of described wide-area transmission is multiplexed into the 3rd transmission span; And

Local transport overhead information multiplexing module is used for the Overhead of described local transmission is multiplexed into the 4th transmission span.

33. device as claimed in claim 29 also comprises:

Select module, be used for selecting described first and second transmission spans based on the amount of broadcast data of described wide-area transmission and the amount of broadcast data of described local transmission.

34. a method that is used for receiving at wireless broadcast network data comprises:

Receive broadcast transmitted by Radio Link, described broadcast transmitted comprises wide-area transmission and local transmission, and described wide-area transmission is that a plurality of transmitters from described network send, and described local transmission is that a subclass from described a plurality of transmitters sends;

If receiving described wide-area transmission, then demultiplexing goes out the data of described wide-area transmission from first transmission span; And

If receiving described local transmission, then demultiplexing goes out the data of described local transmission from second transmission span;

Wherein, described wireless broadcast network utilizes OFDM (OFDM);

Wherein, the data of the data of described wide-area transmission and the transmission of described local are Time Division Multiplexing, wherein, described first transmission span comprises all frequency subbands that carry out transfer of data in the very first time section that is used in a frame, and wherein, described second transmission span comprises all frequency subbands that carry out transfer of data in second time period that is used in described frame.

35. method as claimed in claim 34, wherein, the very first time section of described wide-area transmission is prior to second time period of described local transmission.

36. method as claimed in claim 34 also comprises:

If receiving described wide-area transmission,, handle the data of described wide-area transmission then according to the first demodulation code plan; And

If receiving described local transmission,, handle the data of described local transmission then according to the second demodulation code plan.

37. method as claimed in claim 34 also comprises:

If receiving described wide-area transmission, then demultiplexing goes out the Overhead of described wide-area transmission from the 3rd transmission span; And

If receiving described local transmission, then demultiplexing goes out the Overhead of described local transmission from the 4th transmission span.

38. method as claimed in claim 37, wherein, the Overhead of described wide-area transmission indicates the frequency and the time location of each data channel of described wide-area transmission, and wherein, the Overhead of described local transmission indicates the frequency and the time location of each data channel of described local transmission.

39. method as claimed in claim 34 also comprises:

If receiving described wide-area transmission, then:

Demultiplexing goes out first frequency pilot sign from the 3rd transmission span,

Based on described first frequency pilot sign, obtain first channel estimating of described wide-area transmission, and

Utilize described first channel estimating, handle the data of described wide-area transmission.

40. method as claimed in claim 39 also comprises:

If receiving described local transmission, then:

Demultiplexing goes out second frequency pilot sign from the 4th transmission span,

Based on described second frequency pilot sign, obtain the second channel of described local transmission and estimate, and

Utilize described second channel to estimate, handle the data of described local transmission.

41. method as claimed in claim 40, wherein, described first and second channel estimating are estimated to be associated with first and second impulse responses with different length respectively.

42. method as claimed in claim 41 also comprises:

The operation of execution thresholding is made zero with the first impulse response estimated channel tap that will be lower than first predetermined threshold; And

The operation of execution thresholding is made zero with the second impulse response estimated channel tap that will be lower than second predetermined threshold.

43. method as claimed in claim 42, wherein, described first predetermined threshold equals described second predetermined threshold.

44. method as claimed in claim 40 also comprises:

If receiving described wide-area transmission, then utilize at least one time domain filtering in first set to handle described first frequency pilot sign, to obtain described first channel estimating; And

If receiving described local transmission, then utilize at least one time domain filtering in second set to handle described second frequency pilot sign, estimate to obtain described second channel.

45. method as claimed in claim 44, wherein, at least one time domain filtering in described first and second set has different length, different coefficients, or length is all different with coefficient.

46. a kind of device in the wireless broadcast network comprises:

Receiver unit, be used for receiving broadcast transmitted by Radio Link, described broadcast transmitted comprises the transmission of wide-area transmission and local, and described wide-area transmission is that a plurality of transmitters from described network send, and described local transmission is that a subclass from described a plurality of transmitters sends; And

Demodulation multiplexer, be used for: if receiving described wide-area transmission, then demultiplexing goes out the data of described wide-area transmission from first transmission span, and, if receiving described local transmission, then demultiplexing goes out the data of described local transmission from second transmission span;

Wherein, described wireless broadcast network utilizes OFDM (OFDM), wherein, the data of the data of described wide-area transmission and the transmission of described local are Time Division Multiplexing, wherein, described first transmission span comprises all frequency subbands that carry out transfer of data in the very first time section that is used in a frame, and wherein, described second transmission span comprises all frequency subbands that carry out transfer of data in second time period that is used in described frame.

47. device as claimed in claim 46 also comprises:

Data processor, be used for: if receiving described wide-area transmission, then handle the data of described wide-area transmission according to the first demodulation code plan, and, if receiving described local transmission, then handle the data of described local transmission according to the second demodulation code plan.

48. device as claimed in claim 46, wherein, described demodulation multiplexer also is used for: if receiving described wide-area transmission, then demultiplexing goes out the Overhead of described wide-area transmission from the 3rd transmission span, and, if receiving the local transmission, then demultiplexing goes out the Overhead of described local transmission from the 4th transmission span.

49. device as claimed in claim 46 also comprises:

Channel estimator, be used for: if receiving described wide-area transmission, first frequency pilot sign that goes out based on demultiplexing from the 3rd transmission span then, obtain first channel estimating of described wide-area transmission, and, if receiving described local transmission, then second frequency pilot sign that goes out based on demultiplexing from the 4th transmission span obtains the second channel of described local transmission and estimates; And

Demodulator, be used for: if receiving described wide-area transmission, then use described first channel estimating to handle the data of described wide-area transmission, and, if receiving described local transmission, then use described second channel to estimate to handle the data of described local transmission.

50. device as claimed in claim 46, wherein, by be tuned to single radio frequency, described receiver unit receives the transmission of described wide-area transmission and described local simultaneously.

51. a kind of device in the wireless broadcast network comprises:

Receiver module, be used for receiving broadcast transmitted by Radio Link, described broadcast transmitted comprises the transmission of wide-area transmission and local, and described wide-area transmission is that a plurality of transmitters from described network send, and described local transmission is that a subclass from described a plurality of transmitters sends;

The wide-area transmission demultiplexing module is used for: if receiving described wide-area transmission, then demultiplexing goes out the data of described wide-area transmission from first transmission span; And

Local transmission demultiplexing module is used for: if receiving described local transmission, then demultiplexing goes out the data of described local transmission from second transmission span;

Wherein, described wireless broadcast network utilizes OFDM (OFDM), wherein, the data of the data of described wide-area transmission and the transmission of described local are Time Division Multiplexing, wherein, described first transmission span comprises all frequency subbands that carry out transfer of data in the very first time section that is used in a frame, and wherein, described second transmission span comprises all frequency subbands that carry out transfer of data in second time period that is used in described frame.

52. device as claimed in claim 51 also comprises:

The wide area transmission data processing module is used for: if receiving described wide-area transmission, then handle the data of described wide-area transmission according to the first demodulation code plan; And

The local area transmission data processing module is used for: if receiving described local transmission, then handle the data of described local transmission according to the second demodulation code plan.

53. device as claimed in claim 51 also comprises:

Wide-area transmission Overhead demultiplexing module is used for: if receiving described wide-area transmission, then demultiplexing goes out the Overhead of described wide-area transmission from the 3rd transmission span; And

Local transport overhead information demultiplexing module is used for: if receiving described local transmission, then demultiplexing goes out the Overhead of described local transmission from the 4th transmission span.

54. device as claimed in claim 51 also comprises:

The first frequency pilot sign demultiplexing module is used for: if receiving described wide-area transmission, then demultiplexing goes out first frequency pilot sign from the 3rd transmission span;

The second frequency pilot sign demultiplexing module is used for: if receiving described local transmission, then demultiplexing goes out second frequency pilot sign from the 4th transmission span;

The first channel estimating acquisition module is used for: if receiving described wide-area transmission, then based on described first frequency pilot sign, obtain first channel estimating of described wide-area transmission;

Second channel is estimated acquisition module, is used for: if receiving described local transmission, then based on described second frequency pilot sign, obtain the second channel of described local transmission and estimate;

The wide area transmission data processing module is used for: if receiving described wide-area transmission, then utilize described first channel estimating, handle the data of described wide-area transmission; And

The local area transmission data processing module is used for: if receiving described local transmission, then utilize described second channel to estimate, handle the data of described local transmission.

Images