Embodiment
The purpose of this invention is to provide and can be used for making things convenient for the wireless terminal test example as the one or more carrier waves that with the base station that is in one or more geographic areas or other devices communicatings the time, will use and/or the method and apparatus of a frequency band.Each embodiment of the present invention uses beacon signaling, with convenient carrier wave and/or the frequency band that detects and select to use.In the application's context, beacon is the narrow band signal that comprises one or more higher-wattages that send simultaneously.Each interior narrow band signal of beacon signal can be corresponding with a single-tone.Beacon signal is used usually than sending the used high-power power of data-signal and is sent, and for example uses 2,5,20,100 even more times power as the data-signal peak power to send.
Method and apparatus of the present invention can be used for plurality of communication systems, but is specially adapted to the Frequency Division Multiplexing system such as ofdm system.
Method and apparatus of the present invention will be that exemplary situation describes with an OFDM (OFDM) system, use beacon signal to support a kind of method of simple and efficient relatively and/or practical discovery carrier wave according to the present invention.As already pointed out, beacon signal is a high power signals, and power is usually than having much higher with any single pilot tone of beacon signal same band or data-signal.In fact, beacon signal often than the pilot signal or the data loudness of a sound manyfold of a standard, makes them relatively easily detect.Because beacon takies very little bandwidth usually, the frequency of for example single-tone, so beacon signal (sound) also is relatively easy definite.Have in beacon signal under the situation of a plurality of sounds, in some embodiments of the invention, the frequency of a sound in the beacon signal sound, for example the frequency of the beacon signal sound that frequency is high or minimum in the beacon signal is as the frequency of beacon signal, in some cases, this is used for determining that the sound of beacon signal frequency is to send than the power that other sounds are big in the beacon signal.Yet, also can use other approach of determining the transmission frequency of beacon signal, need only this approach and realize not contradiction of method of the present invention.The common duration of beacon signal is short, and it takies an OFDM symbol transmit time segments in an exemplary OFDM embodiment.Beacon signal and common data are compared normally less transmission with the control signaling.
Fig. 1 shows the diagrammatic sketch 100 of the exemplary beacon signaling that can use in a service frequency bands.A service frequency bands is the bandwidth of disposing the system that is considered.For example, some service frequency bands is 1.25MHz, and some other be 5MHz.Trunnion axis 102 expression frequencies.The service frequency bands of a 1.25MHz of scope 104 expressions.Carrier frequency is expressed as f
C106, usually (though not necessarily will) be in the central authorities of service frequency bands 104.Send beacon signal from a base station on downlink broadcast channel, each beacon signal for example is a single-tone in single OFDM symbol, and all or most of sector transmission power concentration are on this beacon signal sound.Beacon signal periodically sends, for example per 90 milliseconds once.Can send dissimilar beacon signals at different time, for example slope beacon, sector beacon and carrier wave beacon.Should be noted that slope is a cell identifier.In some embodiments, slope and the sector beacon position in frequency domain can change (frequency hopping) in time, and the relative carrier wave in the position of carrier wave beacon in frequency domain is fixed.Fig. 1 shows at the first slope beacon 108 of time T 1 appearance, in first sector beacon 110 of time T 2 appearance, at the second slope beacon 112 of time T 3 appearance, at second sector beacon 114 of time T 4 appearance and the carrier wave beacon 116 that occurs in time T 5.Should be noted that, the frequency of slope beacon 108,112 and sector beacon 110,114 be not fix but change in time, and the fixed-site of carrier wave beacon 116 is at f
CB, relative carrier frequency f
C106 have a fixing skew 118.In some embodiments, carrier type beacon 116 sends to such an extent that lack than slope and sectors type beacon in time, and for example per 16 beacon slots send a carrier wave beacon 106.
Fig. 2 has provided illustration Figure 200 0 of another similar one exemplary embodiment of the beacon signaling that is shown time-frequency lattice.In Fig. 2, trunnion axis 2004 express times, and vertical axis 2002 expression down-link frequencies or sounds.Every lattice of vertical axis are represented a sound 2008, and every lattice of trunnion axis are represented an OFDM symbol 2010.Each blockage is illustrated in the single-tone in the OFDM symbol among the figure, is sometimes referred to as a phonemic notation (tone-symbol).Grid 2006 shows the situation of 10 sounds 2008 during 30 OFDM symbols 2010, i.e. 300 phonemic notations.Each phonemic notation can be used to transmit a beacon signal, common/control data, and also can stay need not.Icon 2016 is shown the carrier wave beacon tones grid 2018 of the Pingyin hachure of fetching water, the slope beacon tones is shown since the downward-sloping hatched grid 2020 of left-to-right, the sector beacon sound is shown since the left-to-right hatched grid 2022 that is inclined upwardly, and general data/control sound is shown the grid 2024 of beating cross-hauling.Stay in the grid 2006 and stay no sound during the grid of not beating shade is illustrated in the OFDM symbol.In this example of Fig. 2, the OFDM symbol that beacon signal is a special use, nearly all down-link transmitting power all concentrates on this single-tone, and the power on the every other sound is near zero.In one embodiment, beacon signal periodically sends, and makes that the time interval between any two beacon signals in succession is a steady state value, is called beacon slot.Therefore, a beacon signal is arranged in a beacon slot.Fig. 2 shows one and comprises 4 exemplary beacon slots 1012 of OFDM symbol in succession, one of them OFDM symbol be used for beacon signal and in addition 3 OFDM symbols be used for transmitting data/control signaling.Fig. 2 also shows the different situation in frequency tone position of different beacon signals.The phoneme of carrier wave beacon tones is put and is maintained fixed in the example of Fig. 2, and the phoneme of slope and sector beacon sound is put saltus step in time; The carrier wave beacon tones is in than any slope or all low frequency of sector beacon sound.In Fig. 2, the carrier wave beacon lacks than slope and sector beacon and sends, and just sends a carrier wave beacon every two slope beacons and two sector beacon.This beacon tones pattern repeated by a bigger time interval that is called overtime crack.In the example of Fig. 2, a carrier wave beacon appears in each overtime crack, and each overtime crack comprises 5 beacon slots.
Fig. 2 is used for illustration various designs of the present invention and feature.According to the present invention, an one exemplary embodiment can be: 113 down link sounds are arranged, per 904 OFDM symbols have a beacon signal, a beacon slot duration is 90 milliseconds, 16 beacon slots are striden in an overtime crack, and the duration is 1.44 seconds in other words, each overtime crack has one to be in the carrier wave beacon that a fixing phoneme is put, and there are 15 slope/sector beacon in each overtime crack.Some one exemplary embodiment can be that each overtime crack has 25 beacon slots.
Should be noted that in some embodiments, in a service frequency bands, the frequency tone of a carrier wave beacon is lower than the frequency tone of any slope or sector beacon.As can know after a while see, this sound disposes and helps search the carrier wave beacon signal.As can be seen, if the frequency tone of carrier wave beacon is higher than any slope or sector beacon, also can obtain same effect.
Fig. 3 is illustrated in the schematic diagram 700 that different regions are deployed in different service frequency bands the exemplary carrier wave deployment scenario in the unconventional frequency band.Trunnion axis 701 expression frequencies.In Fig. 3, unconventional frequency band 702 has the bandwidth of 50MHz altogether.In a FDD system, this 50MHz be divided into comprise two frequency bands (704,706), frequency band 704 for down links with and another frequency band 706 is kept supplying line link usefulness.Unconventional frequency band 702 also comprises a separation band 708 that is between downlink band 704 and the uplink band 706.In some embodiments, unconventional frequency band 702 is divided into a downlink band and a uplink band and does not comprise a separation band.Fig. 3 also shows a service provider has 1.25MHz in down link and up link service frequency bands.Yet the service frequency bands of down link and up link is different in different geographic areas, and the spacing between the carrier wave of down link and up link also has different.In an area, the service provider has downlink traffic frequency band 710 and uplink service frequency band 712, has intercarrier apart from 714; And in another area, the service provider has downlink traffic frequency band 716 and uplink service frequency band 718, has intercarrier apart from 720.
Because wireless terminal is not known the position of down link and uplink service frequency band, it must carry out a searching carrier process.The searching carrier process comprises two general step.At first step, wireless terminal promptly scans possible service frequency bands, whether has beacon signal by checking the energy measuring in the down link signal that is received.After detecting a beacon signal, wireless terminal is just in carrier wave beacon signal of second step search, with the discriminatory carrier position.
No matter in which step, for detected beacon signals, wireless terminal all will be set a search rate, monitors that at one be down link signal in the search frequency band at center with this search rate.In one embodiment, search frequency band has the bandwidth identical with service frequency bands, for example is 1.25MHz.The advantage of doing like this is that wireless terminal can such as the RF filter, be used for searching carrier process and general service with same hardware device.
Notice that for a given searching carrier frequency, corresponding search frequency band may not overlap with service frequency bands, partly overlaps or overlaps fully.If search frequency band and service frequency bands do not overlap, wireless terminal just can not detect any beacon signal in the time interval of any one beacon slot.If search frequency band and service frequency bands overlap fully, wireless terminal will detect a beacon signal in the time interval of any one beacon slot.If search frequency band and service frequency bands partly overlap, wireless terminal may detect also in the time interval of any one beacon slot and may detect less than any beacon signal.
Fig. 4 illustrates the schematic diagram 800 of exemplary carrier search methods designed according to this invention.Vertical axis 802 is represented frequency axiss and trunnion axis 804 express time axles in the drawing that Fig. 4 comprises.Fig. 4 also comprises a downlink band 806.Downlink band 806 comprises a low-limit frequency 807 and a plurality of service frequency bands, and one of them service frequency bands is the service frequency bands 808 of the current location of WT.Service frequency bands 808 comprises the beacon signal that comprises carrier wave beacon and slope/sector beacon that periodically sends, and slope/sectors type beacon sends morely than carrier type beacon.Icon 801 is shown the blockage 810 of a band horizontal shading line with exemplary carrier type beacon among the figure, is with oblique hatched blockage 812 and exemplary slope/sector type beacon is shown.Beacon in the service frequency bands 808 has used the shadow representation of icon 801.Carrier wave beacon 810 is minimum beacons of beacon type medium frequency in the service frequency bands 808.Fig. 4 also shows a search frequency band 814 with search bandwidth 816.Search frequency band bandwidth 816 has identical width with the service frequency bands bandwidth.Search frequency band 814 moves according to search rate during search procedure, is shown search frequency band 814a, 814b, 814c at different time.The amount of movement of step-length 818 search frequency band 814 when not finding a beacon one first Looking Out Time interim.Search rate adjustment amount 820 is according to the amount at one first a Looking Out Time interim detected beacon mobile search frequency band 814.Adjustment amount 820 can be with the position change of detected beacon in search frequency band 814.Two first Looking Out Times in succession (822,824) at interval have been shown: during first first Looking Out Time interval 822, do not detect beacon, and during second first Looking Out Time interval 824, detect a beacon 826 in the schematic diagram 800.At second first Looking Out Time is a duration second Looking Out Time interval 828 longer at interval than first Looking Out Time at interval after 824, and it comprises two detected in succession carrier wave beacons 830,832.
Now the carrier search methods that this is exemplary will be described.Wireless terminal begins first step, is arranged to make search frequency band 814 to cover the low side of downlink band 806 search rate, shown in 814a.One section of the down link signal of wireless terminal monitors search frequency band 814a is about first Looking Out Time, time of 822 at interval of the beacon slot of smallest number.For example, first Looking Out Time is set to more longer slightly than beacon slot, for example is the duration of two beacon slots.For example, be that first Looking Out Time can be set to 180 milliseconds at interval under 90 milliseconds the situation at beacon slot.
If wireless terminal does not detect any beacon signal in first first Looking Out Time interval 822, wireless terminal just thinks that search frequency band 814a and service frequency bands 808 do not overlap.So wireless terminal improves a step-length 818 with search rate.Step-length 818 should not surpass the amount of bandwidth 816 of search frequency band 814.In an example shown, step-length 818 equals the amount of bandwidth 816 of search frequency band 814, for example is 1.25MHz.In one embodiment, step-length is slightly smaller than the amount of bandwidth of search frequency band, for example is 1.00MHz, or be search frequency band amount of bandwidth 1/2nd.
After step-length 818 of search rate raising, wireless terminal is provided with new search rate and corresponding new search frequency band 814b.Similarly, one section second first Looking Out Time of the down link signal of the search frequency band 814b that wireless terminal monitors is new is 824 time at interval.If do not detect beacon signal, wireless terminal improves a step-length 818 with search rate again, and repeats this search procedure.If find a beacon signal, as shown in this example, wireless terminal proceeds to second step.
Should be noted that detected beacon signal can be a carrier wave beacon signal in first step, also can be the beacon signal of other types.If search frequency band and service frequency bands partly overlap, detected beacon signal may not be a carrier wave beacon signal, and search frequency band may even not cover the frequency tone of carrier wave beacon.This is the situation of Fig. 4 example, and detected beacon 826 is a slope/sectors type beacons 812, and search frequency band 814b does not cover the sound of carrier type beacon 810.When second step began, wireless terminal was at first adjusted search rate, will cover the carrier wave beacon to guarantee the search frequency band 814c through adjusting.For example, suppose that the carrier wave beacon is all lower than any slope or sector beacon on frequency, the situation as shown in Fig. 4 example.So wireless terminal can be adjusted search rate, make detected beacon tones be in the high-end of search frequency band through adjusting or be in the high-end of beacon tones position possible in any given search frequency band.In Fig. 4 example, wireless terminal is adjusted to search frequency band 814c by adjustment amount 820 from search frequency band 814b with search frequency band 814, and the frequency of detected beacon 826 is placed top near frequency band 814c.Search frequency band 814c comprises the frequency that the carrier wave beacon is used.
One section of the down link signal that wireless terminal proceeds to the search frequency band 814c of supervision through adjusting is about second Looking Out Time, time of 828 at interval in the overtime crack of smallest number.For example, second Looking Out Time is set to more longer slightly than overtime crack.For example, in an exemplary embodiment, overtime crack is approximately 1.44 seconds, and second Looking Out Time can be set to 1.5 seconds at interval.In second Looking Out Time interval 828, wireless terminal can detect a plurality of beacon signals.Wireless terminal should be according to the feature identification of the carrier wave beacon tones beacon signal 830,832 related with the carrier wave beacon tones.For example, in some embodiments, the carrier wave beacon signal accurately repeats overtime crack.In some embodiments, the carrier wave beacon tones is the minimum beacon tones of frequency in the service frequency bands.In some embodiments, the carrier wave beacon tones is the highest beacon tones of frequency in the service frequency bands.In some embodiments, the carrier wave beacon tones is fixed, and the beacon tones of other types, and slope/sector beacon sound for example is a frequency hopping in time.
The flow chart 400 of Fig. 5 shows the exemplary method of determining the carrier frequency position according to the present invention.In step 402, start carrier search methods by wireless terminal, for example start during in a unknown position place connection and initialization when wireless terminal.Proceed to step 404, wireless terminal is set to low-limit frequency with search rate (SF).In some other embodiment, described beginning search rate can be set to and the corresponding frequency of last known search frequency band that comprises last known carrier frequency.Operation proceeds to step 406, and wireless terminal monitors is the 1.25MHz frequency band at center with SF, seeks the beacon signal that the base station sent.Then, in step 408, whether the wireless terminal check detects a beacon in very first time interval.That is to say that if beacon slot is about 90 milliseconds, the very first time can be taken as between 90 to 180 milliseconds at interval.That is to say wireless terminal can check whether there is a beacon signal in 90 or 180 milliseconds in the 1.25MHz frequency band that with SF is the center.If detect a beacon signal in (for example, 180 milliseconds) at interval from the very first time that begins to monitor current frequency band, operation just proceeds to the step 428 after the detected beacon signals; Yet if do not detect beacon signal beginning to monitor in very first time that current frequency band rises at interval, operation just proceeding to step 410.
Suppose to detect a beacon signal,, adjust SF, make detected beacon tones be in the high-end of adjusted search frequency band so operation proceeds to step 428 in step 408.Then, operation proceeds to step 412.Find that a beacon means the search frequency band of finding to comprise carrier frequency and carrier frequency beacon.Now, continue to monitor that by wireless terminal the beacon in the current search frequency band detects and identifies a carrier wave beacon (it is distinguished mutually with slope/sector beacon) with wait until always, just can determine the position of carrier wave beacon.In step 412, determine whether any detected beacon can be identified as a carrier wave beacon in current frequency band.Slope and sector beacon are deferred to a frequency hop sequences frequency hopping in time.In some embodiments, the carrier wave beacon tones can be identified as a beacon signal of not deferring to frequency hop sequences.In some embodiments, carrier frequency can be identified as certain beacon signal that appears in the search frequency band, for example in search frequency band, be lower than the beacon signal of slope or sector beacon near the precalculated position.Because the carrier frequency beacon fixes, and repeat at interval with regular time, so wireless terminal can wait until in some embodiments that receiving two carrier wave beacons in succession draws sure recognition result again.If also do not identify the carrier wave beacon in step 412, operation proceeds to step 414, and wireless terminal continues the monitor beacons signal.In step 416, periodically whether check has detected another beacon signal.When step 416 detected another beacon signal, operation proceeded to step 412, and whether check once more has any detected beacon can be identified as a carrier wave beacon in current frequency band.If the check announcement in step 416 does not detect a beacon signal, operation just proceeding to step 418, carries out time-out check.In step 418, whether first detected beacon has passed through second Looking Out Time (for example, 1.5 seconds) at interval in current this group from detecting in the wireless terminal test.In this example, the carrier wave beacon repeated in per 1.44 seconds.If also there is not 1.5 seconds the time interval (time-out time), operation proceeds to step 414, continues monitor beacons.Yet, if passed through 1.5 seconds timeout interval, wireless terminal can't be successfully obtain and identify a carrier wave beacon at a reasonable time at interval, and for example the signaling channel quality has been reduced to below the acceptable degree after detect first (slope/sector) beacon of current group.In step 417, with the increment of a step-length of search rate raising, for example 1.25MHz changes to a new search frequency band.Operation proceeds to step 406 from step 417, uses this new search frequency band to continue search.
Turn back to step 412, if detected beacon in the current search frequency band can be identified as a carrier wave beacon, operation just proceeds to step 420.In step 420, set downlink carrier frequency according to the carrier frequency of institute's detection and Identification.Between the frequency of carrier wave beacon and downlink carrier frequency, can there be a predetermined and known skew.Then, in step 422, wireless terminal is listened to the information that will uplink carrier frequency be determined with determined downlink carrier frequency from downlink channel.In some embodiments, uplink carrier can be positioned at from fixing side-play amount place of downlink carrier.In some embodiments, the constant offset amount between down link and the uplink carrier can be known for wireless terminal in advance, so signaling step 422 can be omitted.Then, in step 424, wireless terminal is set uplink carrier frequency, thereby can carry out proper communication between wireless terminal and base station.In step 426, search operation finishes.In step 422, wireless terminal can also obtain other system information, such as the service provider's of current this service frequency bands of operation identifier.Wireless terminal can be compared the service provider's that found identifier with its service agreement, to determine whether to insert this detected service frequency bands.In addition, the energy of detected beacon signal is told the channel quality of this service frequency bands of wireless terminal, and wireless terminal can determine whether to insert this detected service frequency bands in view of the above.
Turn back to step 408, if do not detect a beacon signal in the very first time at interval, what wireless terminal just it is contemplated that it checks is wrong search frequency band; Therefore operation proceeds to step 410.In step 410, search rate is improved a step-length, for example 1.25MHz sets a new search frequency band.Operation turns back to step 406 from step 410, begins to monitor the beacon in this new search frequency band.
Whether be maximum allow SF in the processing that increases progressively in step 410,417 if can be set to check current SF, if this is the case, search frequency band will transit to the minimum SF of permission, rather than normally the increasing progressively of 1.25MHz.
Above time and frequency all are exemplary, can change according to concrete system realization situation.
Fig. 6 illustration an example communications system 10 that realizes according to the present invention.Though be sector, each sub-district shown in Fig. 6, in some embodiments, in the system partly or entirely the sub-district can be the sub-district of many sectors.Example system 10 comprises a plurality of sub-districts (sub-district 1 (2), sub-district 2 (2 '), sub-district M (2 ")).(sub-district M (2 ")) represents that respectively (BS 1 (12), BS 2 (12 '), a BS M (wireless coverage area of 12 ") in a base station for sub-district 1 (2), sub-district 2 (2 ') in each sub-district.Have at least two base stations that are in diverse location to use different service frequency bands in the system 10.Some base station can have the cellular coverage of overlapping in the system 10, and some base station have with system 10 in the cellular coverage that do not overlap of the zone of other BS.System 10 also comprise one respectively by network link (4,4 ', (BS 1 (12), BS 2 (12 '), the network node 3 that BS M (12 ")) connects for 4 ") and base station.Network node 3 for example is that a router also is connected with other network nodes with the internet by network link 5.Network link (4,4 ', 4 ", 5) can be optical fiber link for example.Each sub-district comprises a plurality of wireless terminals that are connected with the base station of sub-district by Radio Link, if these wireless terminals are mobile devices, they can move in system 10 everywhere.In sub-district 1 (2), a plurality of wireless terminals (WT1 (14), WT N (16)) that are shown mobile node (MN 1 (14) to MN N (16)) use signal of communication (13,15) to communicate by letter with base station 1 (12) respectively.In sub-district 2 (2 '), a plurality of wireless terminals (WT1 ' (14 '), WT N ' (16 ')) that are shown mobile node (MN 1 ' (14 ') are to MN N ' (16 ')) use signal of communication (13 ', 15 ') to communicate by letter with base station 2 (12 ') respectively.At sub-district M (in 2 "), a plurality of mobile nodes (MN 1 " (14 ") that are shown are to MN N " (16 ")) wireless terminal (WT 1 " (14 "), WT N " (16 ")) use signal of communication (13 ", 15 ") and base station M (12 ") to communicate by letter respectively.Each portable terminal can be corresponding with a different mobile subscriber, therefore is sometimes referred to as user terminal.Signal (13,15,13 ', 15 ', 13 ", 15 ") can be OFDM (OFDM) signals for example.
According to method of the present invention, the base station (12,12 ', 12 ") transmission comprises the broadcast singal of the beacon signal that transmits carrier information.Mobile node (14,16,14 ', 16 ', 14 ", 16 ") are starting, are realizing when entering a new sub-district and/or losing carrier signal carrier search methods of the present invention.The base station (12,12 ', 12 ") and wireless terminal (MN 1, MN N, and MN 1 ', MN N ', MN 1 ", MN N ") (14,16,14 ', 16 ', 14 ", 16 ") are respectively carried out method of the present invention.Therefore, signal (13,15,13 ', 15 ', 13 ", 15 ") comprise the signal of illustrated in this application type, they send according to the present invention.
Fig. 7 illustration an exemplary base station-access node 200 of realizing according to the present invention.Base station 200 can be exemplary BS 12,12 ', 12 among Fig. 6 " in any one.Base station 200 sends beacon signals, for example such as in those beacon signals shown in Fig. 1 or Fig. 2.Different beacons sent in the different time.The beacon signal that sends in any sub-district can be relevant with sub-district and/or sector, and different cell/sections sends different beacon signals.Base station 200 comprises receiver 202, transmitter 204, processor 208, I/O interface 210 and memory 212, and these unit link together by bus 214, can pass through this bus exchanging data and information.Base station 200 comprises the reception antenna 216 that is connected with receiver 202, and BS 200 can be by the uplink signal of reception antenna 216 receptions from a plurality of wireless terminals.Base station 200 also comprises the transmitting antenna 218 that is connected with transmitter 204, and BS 200 sends the down link signal that comprises broadcast singal and user's special signal by antenna 218 to a plurality of WT.Broadcast singal comprises the beacon signal that some comprise the carrier wave beacon signal, and also comprises the broadcast message with downlink carrier information and uplink carrier associating information in some embodiments.Receiver 202 comprises a decoder 220 that the uplink signal that is received is decoded, and transmitter 204 comprises an encoder 222 that downlink data/information was encoded before sending.I/O interface 210 is connected to internet and/or other network nodes for example other base stations, aaa server node, home agent node, router etc. with base station 200.Memory 212 stores some routines 224 and data/information 226.Processor 208 for example CPU is carried out the routine 224 that is stored in the memory 212 and is used the data/information 226 that is stored in the memory 212, makes base station 200 according to work of the present invention.
Routine 224 comprises communication routines 228 and base stations control routine 230.Communication routines 228 is used for controlling base station 200, makes it carry out various traffic operations and the various communication protocols of execution.Base stations control routine 230 is used for controlling base station 200, makes it realize each step of method of the present invention.Base stations control routine 230 comprises scheduler module 232, beacon routine 234 and uplink carrier sign (ID) signalling module 240.Scheduler module 232 is used for controlling and sends scheduling and/or communication resource distribution, so module 232 can be used as scheduler.Beacon routine 234 controls are determined, are produced and the transmission beacon signal by base station 200.Beacon routine 234 comprises beacon definite and generation module 236 and beacon sending module 238.Beacon determines to comprise with generation module 236 usefulness data/information 226 definite current beacon slot information 246 and the generation and current beacon slot information 246 corresponding beacon signals of timing information 248 and beacon infrastructure information 242.Beacon sending module 238 usefulness comprise that the data/information 226 of current beacon slot information 246 and timing information 248 is controlled at reasonable time and sends the beacon signal that is produced.Uplink carrier ID signalling module 240 usefulness comprise that data/information 226 controls of uplink carrier information 276 produce and transmission makes WT can determine the downlink broadcast signals of uplink carrier frequency to the WT transmission.For example, for example determined that by carrier search methods designed according to this invention the WT of downlink carrier frequency can receive one the used uplink carrier in base station 200 and the broadcast singal of the side-play amount between the downlink carrier are provided for one.
Data/information 226 comprises beacon infrastructure information 242, carrier information 244, current beacon slot information 246, timing information 248 and wireless terminal data/information 250.Beacon infrastructure information 242 comprises the feature of the beacon signal that regulation will be determined, produce and be sent by WT 200.Beacon infrastructure information 242 comprises that the beacon slot in type information 252, message breath 254, timing information 256, frequency hopping information 258, sequence information 260, each overtime crack counts information 262 and power information 264.
Type information 252 comprises all kinds of regulation by the beacon of BS 200 transmissions, for example carrier wave beacon, slope beacon, sector beacon.Type information 252 can also comprise that relevant whether specific beacon comes transmission information with identical sound or sound group or whether this specific beacon is in the beacon type information of different time with different sounds or sound group (for example, deferring to a sound frequency hop sequences).For example, in some embodiments, the carrier wave beacon is with identical stationary tone, and slope and sector beacon according to frequency hop sequences at different time with different sounds.
Message breath 254 comprises the sound that beacon that sign sends from BS 200 is used or the information of sound group.Message breath can also comprise the scope that can transmit the sound of beacon signal in the downlink traffic frequency band that is identified at, and the bandwidth of scope that for example is used for the sound of beacon signal in certain embodiments can be less than the bandwidth of service frequency bands.
Timing information 256 comprises when regulation should send the information of a beacon signal.For example, in some embodiments, in each beacon slot, send a beacon signal during a predetermined fixed OFDM symbol transmission time interval.Frequency hopping information 258 for example for can be used to draw a frequency hopping equation or some values of a frequency hop sequences, is used for the beacon of a definite frequency hopping used sound or sound group during specific beacon slot in overtime crack.Sequence information 260 is included in the beacon sequence that sends during the overtime crack.For example, in one embodiment, first beacon in this overtime crack is a carrier wave beacon, and all the other beacons are slope and sector beacon, and these all the other beacons alternately are slope beacon and sector beacon on beacon slot in succession.The beacon slot in each overtime crack several 262 contains and is identified in the overtime crack information of the number of beacon slot in succession, and each the respective beacon time slot in the overtime crack in succession has identical beacon signal.Power information 264 comprises the information of the transmission power level that identifies each beacon signal.In some embodiments, each beacon signal is to send than the much higher predetermined power level of power level that is used for ordinary downlink data and control signaling.
Carrier information 244 comprises downlink carrier information 274 and uplink carrier information 276.Carrier information 244 is relevant with the position.For example, a service provider's base station 200 may have different service frequency bands for different positions.Downlink carrier information 274 comprises carrier wave frequency information 278 and service frequency bands information 280.Downlink carrier frequency information 278 comprises that BS 200 is used for the carrier wave of downlink signaling, for example the downlink carrier in the unconventional frequency band searched for of WT.Service frequency bands information 280 comprises that BS 200 is used for the frequency range of downlink signaling.In some embodiments, service frequency bands is the center with the downlink carrier frequency.Service frequency bands information 280 also comprises the bandwidth of service frequency bands.In some embodiments, all keep invariable everywhere to the bandwidth of service frequency bands in system, but carrier frequency is with position change.Uplink carrier information 276 comprises carrier wave frequency information 282 and service frequency bands information 284.Uplink carrier frequency information 282 comprises that BS 200 is used for the carrier wave of uplink signalling, for example the uplink carrier in unconventional frequency band.Service frequency bands information 284 comprises that BS 200 is used for the frequency range of uplink signalling.In some embodiments, service frequency bands is the center with the uplink carrier frequency.Service frequency bands information 284 also comprises the bandwidth of service frequency bands.In some embodiments, all keep invariable everywhere to the bandwidth of service frequency bands in system, but carrier frequency is with position change.In some embodiments, the spacing between uplink carrier and the downlink carrier is a fixing side-play amount, and all keep invariable everywhere in system.In some embodiments, the spacing between uplink carrier and the downlink carrier can be with position change.In more such embodiment, uplink carrier ID signalling module 240 is carried out and will be sent the operation of WT with intercarrier apart from information corresponding and/or other uplink carrier information to.
Current beacon slot information 246 comprises time slot index 266 and message breath 268.Time slot index 266 is and a corresponding beacon slot index in overtime crack of beacon signal.Message breath 268 comprises a sound of forming current beacon signal or sound group and the associated power level that concentrates on this sound or the sound group.
Timing information 248 comprises that the OFDM symbol sends regularly, for example in succession OFDM symbol transmission time interval tracking in time in a beacon slot and overtime crack.
WT data/information 250 comprises many group WT data messages (WT 1 data/information 270, WT N data/information 272).WT 1 data/information 270 comprise one group with WT 1 corresponding data/information, such as active session, user, peer node, routing information, user data/information, the resource information for example traffic channel segments and the special-purpose control section of identifier, up link and the downlink allocation of BS 200 distribution with WT 1 communication session.
Server and/or main process equipment can with exemplary base station-access node 200 shown in Figure 4 for example identical the or similar circuit of circuit but have of couple in router satisfy interface and/or the control routine that this specific server/main process equipment requires and realize.Can make equipment realize method of the present invention at such server and/or the control routine in the main frame and/or hardware.
Fig. 8 illustration one according to the present invention realize what can carry out carrier search methods of the present invention for example is the exemplary wireless terminal (terminal node) 300 of a mobile node.This exemplary WT 300 can be among Fig. 6 any one WT (14,16,14 ', 16 ', 14 ", 16 ").Mobile node 300 can be used as portable terminal (MT).Wireless terminal 300 comprises receiver 302, transmitter 304, processor 306, user I/O equipment 308 and memory 310, and these unit link together by bus 312, can pass through this bus exchanging data and information.Memory 310 comprises some routines 322 and data/information 324.Receiver 302 is connected with reception antenna 316, the down link signal that WT 300 receives from BS by antenna 316, down link signal comprises the beacon signal that transmits carrier information, and also comprises the broadcast singal that links the information of downlink carrier and uplink carrier from the transmission of BS in some embodiments.Receiver 302 comprises the decoder 314 that the coding down link signal that is received is decoded.Transmitter 304 is connected with transmitting antenna 320, and WT 300 will comprise that by transmitting antenna 320 uplink signal of uplink traffic channel signals sends a BS to.Transmitter 304 comprises an encoder 318 that data/information was encoded into the uplink signal of coding before sending to the base station.In some embodiments, decoder 314 and encoder 318 use low-density checksum (LDPC) sign indicating number.Processor 306 for example is a CPU, the data/information 324 in routine 322 in the execute store 310 and the use memory 310, and the work with control WT 300 realizes the method that comprises searching carrier of the present invention.User I/O equipment 308, for example keyboard, keypad, mouse, pick-up, camera, display, loud speaker etc. make the user of WT 300 can import the user data that will give peer node and export the user data/information from peer node that is received.
Routine 322 comprises communication routines 326 and wireless terminal control routine 328.Wireless terminal control routine 328 comprises that searching carrier routine 330, downlink carrier are provided with module 332, uplink carrier determination module 334 and uplink carrier module 336 is set.
Communication routines 326 is carried out the used various communication protocols of WT 300.The operation of the receiver 302 of WT control routine 328 control WT, transmitter 304, user I/O equipment 308 realizes method of the present invention.Searching carrier routine 330 makes WT 300 realize carrier search methods designed according to this invention.Searching carrier routine 330 comprises search initialization module 338, beacon monitors and detection module 340, time block 342, supervision frequency band adjusting module 344 and carrier detection module 346.
Search initialization module 338 is used and is comprised search log-on message 368 and also comprise the frequency band that the data/information 324 of the carrier information of being stored 352 selects first to monitor in some embodiments when the search beginning.The information relevant with this interval that will search for is stored in the current search band information 356 by module 338.For example, at some embodiment or under some situation, search initialization module 338 begins search in a frequency band of the least significant end that is in the downlink band that will search for that is identified as search start information 368.In some other embodiment or under some other situation, search initialization 338 at a frequency band of the carrier information stored 352 signs (for example, a frequency band in one group of previous downlink traffic frequency band that uses is such as the downlink traffic frequency band that used last time) in begin search.Search initialization module 338 with the receiver 302 of WT be tuned to selected current search frequency band.
Beacon monitors and detection module 340 uses comprise the supervision that the data/information 324 of system information 350 and current search band information 356 is carried out the downlink signaling in the current search frequency band, with the detection and Identification beacon signal.For example, can concentrate on the beacon signal that this feature identification received on one or several sounds according to high power.Monitor and detection module 340 when detecting a beacon signal at beacon, just will for example sound and timing information be stored in the detected beacon message 358 with the corresponding information of detected beacon signal.In some embodiments, module 340 detects a beacon signal and just makes a Looking Out Time interval interrupt and/or termination, and triggers further operation, and for example service frequency bands adjustment and the Looking Out Time that begins another type are at interval.In other embodiments, detect that one or more beacon signals are not interrupted or cross early stopping beacon Looking Out Time at interval.Time block 342 uses data/information 324 control fixed cycle operators, comprise the beginning Looking Out Time at interval, follow the tracks of at time, check Looking Out Time that the first or second type Looking Out Time finishes at interval and whether expired at interval and when a Looking Out Time expires at interval, trigger some additional operations.Time block 342 with information stores in timing information 354.Monitor that frequency band adjusting module 344 uses the data/information 324 that comprises step-size in search information 368 and search adjustment information 376 to adjust search frequency band, changes current search band information 356.For example, if expired and beacon monitors and detection module 340 does not also detect a beacon signal as time block 342 first indicated first fixed time intervals, monitor that frequency band adjusting module 344 just increases progressively the current search frequency band step-size in search, receiver control 302 retunes to this new search frequency band, signal to time block again, to begin second first Looking Out Time at interval.As another example, consider that beacon monitors and detection module 340 detects a beacon signal in one first Looking Out Time interval, monitor that frequency band adjusting module 344 can change search frequency band according to search adjustment information 376, for example reduce search frequency band, make detected beacon signal be in the top of new search frequency band.Adjusting module 344 search frequency band information stores that this is new is in current search band information 356, and receiver control 302 retunes to new search frequency band, and signals to time block 342, to begin one second Looking Out Time at interval.
Carrier detection module 346 uses and comprises that the data/information 324 of detected beacon message 358 and system information 350 is to obtain detected carrier signal information 360 and determined downlink carrier information 362.For example, can comprise that at the second Looking Out Time detected beacon message 358 of interim pointing out to receive two is in the beacon signal of identical stationary tone and the information in the time interval in the overtime crack of being pointed out by beacon infrastructure information 382 of being separated by, expression detects the carrier wave beacon, thereby carrier detection module obtains detected carrier signal information 360.Then, use downlink carrier/service frequency bands information 378, the information of indication carrier wave frequency and related service frequency bands and the relation (for example position on constant offset between carrier wave beacon tones and the carrier frequency and/or the relative service frequency bands of carrier wave beacon tones border) of carrier wave beacon tones for example, carrier detection module 346 definite downlink carrier information 362.
Downlink carrier be provided with module 332 use data/information 324 of comprising determined downlink carrier information 362 with receiver 302 for example be provided be tuned to this carrier frequency and service frequency bands.
Uplink carrier determination module 334 is determined carrier wave that is used for uplink signalling and the service frequency bands that WT 300 will use.In some embodiments, system all everywhere downlink carrier and corresponding uplink carrier between fixing relation is arranged.In such an embodiment, uplink carrier determination module 334 determines that at downlink carrier the back use comprises data/information 324 definite uplink carrier information 364 of determined downlink carrier information 362 and downlink carrier/uplink carrier information 380 (for example, constant offset of being stored).In some embodiments, downlink carrier is different with spacing between the uplink carrier for base station locations different in the system, for example as shown in Figure 3.In such embodiment, WT 300 with it receiver be tuned on the determined downlink carrier after, WT300 uses module 334 to receive and handle a broadcast singal of information of pointing out to can be used to draw determined uplink carrier information 364 from BS.For example, this broadcast singal can be indicated uplink carrier frequency, perhaps can indicate the skew of uplink carrier frequency with respect to downlink carrier frequency.
Uplink carrier is provided with module 336 and uses the data/information 324 that comprises determined uplink carrier information 364 that transmitter 304 is provided with for example to be tuned to make WT in suitable service frequency bands uplink signal be sent to the base station.
Data/information 324 comprises user data 348, system information 350, the carrier information of being stored 352, timing information 354, current search band information 356, detected beacon message 358, detected carrier signal information 360, determined downlink carrier information 362, determined uplink carrier information 364 and user/equipment/session/resource information 392.
User data comprises data and information, for example with the communication session of WT 300 in to issue the peer-to-peer of WT 300/receive from this peer-to-peer voice, text, user use and/or video data/information.
System information 350 comprises search frequency band range information 366, search start information 368, the first Looking Out Time interval information 370, the second Looking Out Time interval information 372, step-size in search information 374, search adjustment information 376, downlink carrier/service frequency bands information 378, downlink carrier/uplink carrier information 380 and beacon message 381.Search frequency band range information 366 comprises the information of the downlink band that sign will be searched for, for example the downlink band in a unconventional frequency band.Search frequency band range information 366 also comprises the restriction to scope, for example comprises that low-limit frequency and/or minimum search are provided with frequency.Search start information 368 comprises the information of the beginning search frequency band that sign will be used, search frequency band that is in extreme lower position in the downlink band that to search for for example, and/or identify the information that the search that will use begins technology, for example use and be kept at the service frequency bands of successfully determining the last time in the carrier information of being stored 352.The first Looking Out Time interval information 370 comprises the information of one first Looking Out Time of sign duration at interval, if detect any beacon in first Looking Out Time interim, operation will proceed to one second Looking Out Time at interval.The first Looking Out Time interval information 370 comprises that also relevant first Looking Out Time of sign is stopping proceeding to one second Looking Out Time information at interval again after still first Looking Out Time finishes at interval at interval when detecting a beacon signal.In some embodiments, first Looking Out Time is disposed in the scope in 1 to 2 beacon slot time interval, and is perhaps big slightly again.For example, in a beacon slot was 90 milliseconds one exemplary embodiment, first Looking Out Time was set to 180 milliseconds.The second Looking Out Time interval information 372 comprises the information of one second Looking Out Time of sign duration at interval, during this period of time search frequency band is searched for, to discern a carrier wave beacon.The second Looking Out Time interval information 372 comprises that also relevant second Looking Out Time of sign is stopping proceeding to the information of using determined carrier information again after still second Looking Out Time finishes at interval at interval once a definite carrier wave beacon signal.In some embodiments, second Looking Out Time is disposed in the scope in 1 to 2 overtime crack, and is perhaps big slightly again.For example, in an overtime crack was 1.44 seconds one exemplary embodiment, second Looking Out Time was set to 1.5 seconds.Step-size in search information 374 comprise be identified at that a first kind Looking Out Time finishes at interval and when not detecting a beacon signal with the information of current search frequency band Change Example as the step-length that moves to a upper frequency.Search adjustment information 376 comprises the information of after one first Looking Out Time interim detects the beacon signal adjustment amount (for example amount of movement) of control current search frequency band of being used for.For example, in some embodiments, the carrier wave beacon is in fixing frequency location in the service frequency bands, is a sound all lower than any other beacon signal, and beacon tones takies the subrange of certain regulation of service frequency bands.In such an embodiment, search adjustment information 376 can comprise that the position that is used for determining the detected relatively beacon of search frequency band makes detected beacon signal be in the top of search frequency band to guarantee should to detect a carrier wave beacon in second Looking Out Time interim, for example carrier frequency band to be moved to.Downlink carrier/service frequency bands information 378 comprises the information of the relation between sign downlink carrier and the downlink traffic frequency band, and for example the downlink traffic frequency band is to be the center with the downlink carrier, accounts for a designated bandwidth.Information 378 also comprises the information of the relation between sign carrier wave beacon and the carrier frequency, for example the direction of sound number and carrier wave beacon tones offset carrier frequency (be lower than or be higher than carrier frequency).Downlink carrier/uplink carrier information 380 comprises and is used for determining according to a detected downlink carrier information of the uplink carrier frequency of a base station.For example, in some embodiments, uplink carrier departs from the distance of downlink carrier to be fixed, and this fixed value of uplink/downlink intercarrier distance is stored in the information 380.In some embodiments, the uplink/downlink intercarrier is apart from position change, and each BS sends one and has the broadcast that can be used for therefrom drawing the information of uplink carrier by WT 300.In such embodiment, information 380 comprises that the information of discerning this broadcast and some are used for drawing from described broadcast and/or determined downlink carrier the parameter of uplink carrier.
Beacon message 381 comprises beacon infrastructure information 382.Beacon infrastructure information 382 comprises the beacon slot number and the power information in beacon type information, message breath, timing information, frequency hopping information, sequence information, each overtime crack.Exemplary beacon infrastructure information 382 is similar to the front beacon infrastructure information 242 illustrated to exemplary BS 200.
The carrier information of being stored 352 comprises before the perhaps previous carrier wave that has been used for communicating by WT 300 that has been found that by a searching carrier operation and the information of service frequency bands.The carrier information of being stored 352 comprises that in some embodiments indicate the service time of the carrier information that each group is stored and/or the information of frequency of utilization.In such an embodiment, the carrier wave of carrier wave that WT 300 can use since last time or the most frequent use carries out searching carrier.
Timing information 354 comprises that the OFDM symbol sends regularly, for example in succession OFDM symbol transmission time interval tracking in time in a beacon slot and overtime crack.Timing information 354 also comprises the information regularly of following the tracks of, such as also how long remaining in one first Looking Out Time interval or also how long remaining in one second Looking Out Time interval.
Current search band information 356 comprises the information of the setting of sign current search frequency band, for example frequency and bandwidth.Current search band information 356 comprises also when sign begins to search for the information of current search frequency band.
Detected beacon message 358 comprise with at first Looking Out Time at interval and the relevant information of the second Looking Out Time detected beacon of interim, the timing of the sound, beacon that this information comprises each detected beacon use in overtime crack, beacon type etc.For example, one first beacon can be detected, and at least one second beacon can be detected in second Looking Out Time interim in first Looking Out Time interim.Detected carrier signal information 360 comprises the frequency of carrier signal of having determined according to the frequency of at least the first and second detected beacon signals.
Determined downlink carrier information 362 comprises carrier wave frequency information 384 (for example coming the carrier wave of self information 360) and corresponding business band information 386 (for example, the bandwidth of downlink traffic frequency band and the sign position of downlink carrier in service frequency bands information for example placed in the middle).
Determined uplink carrier information 364 comprises carrier wave frequency information 388 (for example from uplink carrier determination module 334) and corresponding business band information 390 (for example, the bandwidth of uplink service frequency band and the sign position of uplink carrier in service frequency bands information for example placed in the middle).
Can insert and use user/equipment/session/resource information 392, for example, user/equipment identification information, the session information that comprises peer node sign and routing information, and such as being the up link of WT 300 distribution and the resource information downlink traffic channel segments and the control channel section, to realize method of the present invention and/or to be used for realizing data structure of the present invention.
Fig. 9 is for making for example flow chart 900 of the exemplary method of BS 200 transmission beacon signals of a base station according to the present invention.Operate in step 902 beginning, connect and the initialization base station.As an initialized part, can be set to 1 by the beacon slot index, beacon slot index minimum in an overtime crack.Operation proceeds to step 904 from step 902.In step 904, make base station work, to obtain the beacon slot index in this overtime crack.Each beacon slot and adjacent beacon slot do not overlap.Each overtime crack comprises the beacon slot of fixed qty.Operation proceeds to step 906 from step 904, and the base station is that next beacon signal is determined beacon type and sound indication according to the beacon slot index.Each beacon is a beacon in a plurality of dissimilar beacons, and each beacon sends on a different sound or one group of sound in same frequency band.In some embodiments, minimum sound has a fixing frequency location in the beacon signal relative band of a first kind.In some embodiments, the beacon of the first kind has all low or all high frequency location of beacon of the every other type that fixing ratio base station sends in service frequency bands.In some embodiments, the beacon signal of the first kind is called the carrier wave beacon.In some embodiments, the beacon of other types comprises slope and/or sector beacon.In some embodiments, slope and/or sector beacon are used the frequency tone of frequency hopping in time.In some embodiments, the beacon signal of the first kind, carrier wave beacon for example, than the less appearance of the beacon signal of other types, for example, each overtime crack has only a carrier wave beacon, and there is a plurality of slopes/sector type beacon signal in each overtime crack.
Then, in step 908, make the base station produce described beacon signal according to the determined information of step 906.Then,, make the base station during described beacon slot, for example during OFDM symbol transmission time interval, send the described beacon signal that produces for the appointment of transmission beacon signal in step 910.Operation proceeds to step 912 from step 910.In step 912, make base station checks beacon slot index whether equal beacon slot index maximum in the overtime crack.If the beacon slot index equals the highest beacon slot index in the overtime crack, show that these beacon signals in this overtime crack all produce, thereby operation proceeds to step 914.In a complete overtime crack, the base station has sent each dissimilar beacons at least once.In step 914, make base station beacon slot index be set to 1, expression is first beacon slot in the new overtime crack.Yet if determine that in step 912 the beacon slot index is not a beacon slot index maximum in the overtime crack, operation just proceeds to step 916.In step 916, make the base station that the beacon slot index is increased progressively.Operation is returned step 904 from step 914 or step 916.
The Figure 10 that forms by Figure 10 A and Figure 10 B for make according to the present invention a wireless terminal (WT) for example WT 300 detect the base station flow chart 1000 of the exemplary method of the carrier signal of BS200 transmission for example that sends beacon signal by one-period ground.This exemplary method starts from step 1002, starts this searching method when wireless terminal connection and/or initialization.Operation proceeds to step 1004 from setting up procedure 1002.
In step 1004, make WT select first frequency band as monitoring frequency band.For example, logical if wireless terminal rigidly connects, WT can use frequency band that WT used last time as selected first frequency band, uses the possible frequency band according to WT operation in the past, perhaps uses a predetermined selected frequency band such as the lowest band in the scope that will search for.Then, operation proceeds to step 1006 from step 1004.
In step 1006, make WT begin to monitor first frequency band, with one the interim very first time detected beacon signals.For example, WT with receiver be tuned to the selected frequency band of step 1004, begin to be received in signaling and any signal that receives of assessment in the selected supervision frequency band, determine whether to receive a beacon signal, for example a beacon signal that comprises the one or more high power narrow signals that send simultaneously.In some embodiments, beacon signal can be a number of different types, for example the first kind is the carrier wave beacon signal, have at a sound minimum in the service frequency bands of corresponding frequencies on the sound of fixing skew to send, the beacon signal of the described first kind uses sound minimum or the highest in the described beacon signal that sends in the service frequency bands of described frequency to send.In some embodiments, the operation of detected beacon signals comprises the energy that detects described beacon signal and the phase place of uncertain described beacon signal.In some embodiments, the very first time is spaced apart the time interval of being a bit larger tham a beacon slot, for example 1 to 2 beacon slot or big slightly again.Then, operation proceeds to step 1008 from step 1006.
In step 1008, whether the WT check has detected a beacon.If detected a beacon, operation just proceeds to step 1010, otherwise operation proceeds to step 1012.In step 1010, WT will monitor that frequency band changes the frequency quantity less than the width of described supervision frequency band.In some embodiments, under some situation, the change of changing into zero Hz of step 1010.In some embodiments, monitor that with monitoring that frequency band changes over to make frequency band places the frequency of detected beacon signal a skew of selecting is in advance arranged from the top that monitors frequency band.In some embodiments, the change of step 1010 is to make the continuation that monitors frequency band is monitored the beacon signal that detect a first kind in its frequency band, for example a carrier wave beacon.Then, operation proceeds to step 1014 from step 1010.
In step 1014, make wireless terminal begin to monitor current supervision frequency band, during one the 3rd period, to detect second beacon signal.For example, the 3rd period can be one and is a bit larger tham and comprises that at least one first kind beacon signal for example therefrom can determine the time interval of the beacon type signal of carrier wave.In some embodiments, the 3rd type time interval was a bit larger tham an overtime crack.Then, operation proceeds to step 1016 from step 1014.
In step 1016, whether the WT check has detected a beacon.If detect a beacon, operation just proceeds to step 1018 from step 1016.In step 1018, inspection to beacon whether the information that is enough to determine carrier wave can be provided.In different embodiment, the beacon that may need to detect varying number could be determined carrier wave according to some specific factors in the beacon signaling (for example, the quantity of beacon type, such as for a beacon type whether feature, the beacon type pattern of beacon signal sequence in overtime crack of the beacon type the sound saltus step).For example, (for example include only two beacon signal types at one, a carrier type and a cell identifier type), distribute among the not saltus step of beacon tones of beacon signal and the embodiment that beacon signal replaces between these two types, receiving two beacon signals in succession should just be enough to determine the carrier wave beacon.As another example, consider such an embodiment: have carrier wave, sub-district (slope) identifier, three different beacon types of sector marker; A fixing sound in the carrier wave beacon service band and sub-district (slope) and sectors type beacon use the sound of saltus step in time; Each beacon slot of base station sends a beacon signal; The sequence that beacon type is deferred in the beacon slot in succession in or the overtime crack of part is (i) slope type beacon, (ii) sector type beacon, (iii) slope type beacon, (iv) sector type beacon, (v) carrier type beacon.In such an embodiment, after must detecting five beacons, possibility could determine carrier wave.As another example, consider such an embodiment: have carrier wave, three different beacon types of slope and sector; A fixing sound in the carrier wave beacon service band and slope and sector beacon are used the sound of saltus step in time; Each beacon slot of base station sends a beacon signal; It at first is the slope during a carrier wave beacon during first beacon slot then is each remaining beacon slot in this overtime crack or the sequence of sector beacon that these beacon types are deferred in an overtime crack.In such an embodiment, the discriminatory carrier beacon may must detect the beacon of carrier wave in succession in two overtime cracks that are separated by.
Suppose that detected beacon signal so far is enough to provide the information of determining carrier wave, operation just proceeds to step 1020 from step 1018.In step 1020, make wireless terminal determine that according to the frequency of at least the first and second beacon signals wireless terminal is in order to obtain the operable frequency of carrier signal of communication service.Yet if so far detected beacon signal does not also provide the information that is enough to determine carrier wave, operation just proceeds to step 1022 from step 1018.In step 1022, make wireless terminal check for the 3rd period whether expired.Wireless terminal does not also detect the abundant required beacon of definite carrier wave as desired if the 3rd period expired, this may represent that WT has moved to outside the operating distance of this base station after detecting first beacon, so wireless terminal should be searched in a new frequency band.Also may be temporary interference to have occurred, hinder detection the carrier wave beacon.If the 3rd period expired, operation is just returned step 1004 from step 1022 by connected node A 1024, restarts search operation.For example, this moment, step 1004 can be selected the next frequency band also do not searched for, and perhaps step 1004 can the current frequency band of repeat search.
Turn back to step 1022, if the 3rd period did not expire, operation just proceeds to step 1026, and wireless terminal continues to monitor the frequency band of current supervision, with detected beacon signals.Then, operation proceeds to step 1016 from step 1026.
Turn back to step 1008, if do not detect a beacon signal, whether operation just proceeds to step 1012, make WT check for first period expired.If first period did not expire, operation proceeds to step 1028 from step 1012, makes WT continue to monitor first frequency band, in interim very first time detected beacon signals.Operation proceeds to step 1008 from step 1028.If first period expired, operation just proceeds to step 1030 from step 1012.In step 1030, make WT will monitor that frequency band changes into second and monitor frequency band, second monitors that frequency band and first monitors that frequency band differs the width that mostly is the supervision frequency band most.Then, in step 1032, WT begins to monitor second frequency band, detected beacon signals during second time interval.In some embodiments, second time interval had and the identical at interval duration of the very first time.Then, operation proceeds to step 1034 from step 1032.
In step 1034, make the wireless terminal check whether detect a beacon.If detect a beacon, operation just proceeds to step 1010, otherwise operation proceeds to step 1036 from step 1034.In step 1036, whether WT checked for second period expired.If second period did not expire, operation just proceeds to step 1038 from step 1036, and WT continues to monitor second frequency band, detected beacon signals during second time interval.Then, operation proceeds to step 1034 from step 1032.
If expire in definite second period of step 1036, expression is unsuccessful to the search of second frequency band, thereby operation proceeds to step 1042 by connected node B 1040.In step 1042, whether the WT check has reached the end of monitoring range.If do not reach the end of monitoring range, operation just proceeds to step 1044 from step 1042, otherwise operation proceeds to step 1046.
In step 1044, make WT will monitor that frequency band changes into another frequency band, this frequency band and last supervision frequency band differ and mostly are the width that monitors frequency band most.In step 1046, make WT will monitor that frequency band changes into another frequency band, this frequency band is in the other end of monitoring range.Operation proceeds to step 1048 from step 1044 or step 1046, and WT monitors this frequency band, detected beacon signals during one the 4th period.In some embodiments, the 4th period is identical with the duration of first and/or second period.
Operation proceeds to step 1050 from step 1048, and whether check has detected a beacon.If detect a beacon, operation just proceeds to step 1010 from step 1050 by connected node C1052.Yet if do not detect a beacon, operation just proceeds to step 1054, and whether WT checked for the 4th period expired.If the 4th period did not expire, operation just proceeds to step 1056 from step 1054, and WT continues to monitor this frequency band, detected beacon signals during the 4th time interval.Then, operation proceeds to step 1050 from step 1056.
Turn back to step 1054, if the 4th period expired, operation just turns back to step 1042 by connected node B 1040.
The flow chart 1100 of the exemplary method of a plurality of base stations of the communication system that Figure 11 comprises at least the first and second base stations that are positioned at different geographic areas for one of operation.First frequency band is used in first base station, and second frequency band different with first frequency band used in second base station.Operation starts from step 1102, and the base station of communication system is switched on.Then, operation proceeds to step 1104 and 1106 from step 1102, can select to proceed to step 1108 and 1110 in some embodiments.
In step 1104, make first base station transmitter that is positioned at place, described first base station during one first period, send a plurality of beacon signals, described a plurality of beacon signal comprises the beacon signal of a first kind and the beacon signal of one second type, and described first period comprises second time interval of the non-overlapping of fixed qty.Step 1104 comprises these operations of substep 1112.At substep 1112, make first base station transmitter send at least one beacon signal in described first frequency band in each described second period, send on the different sounds of dissimilar beacon signals in described first frequency band, the beacon signal of the beacon signal of a described first kind and described second type sends at least once during described first period.Operation is returned step 1104 from the end of step 1104, and the beacon that for example repeats first base station transmitter in another first period during in succession first period of the next one sends.
In step 1106, make second base station transmitter that is positioned at place, described second base station during one the 3rd period, send a plurality of beacon signals, described a plurality of beacon signal comprises the beacon signal of a first kind and the beacon signal of one second type, and described the 3rd period comprises the 4th time interval of the non-overlapping of fixed qty.Step 1106 comprises these operations of substep 1114.At substep 1114, make second base station transmitter send at least one beacon signal in described second frequency band in each described the 4th period, send on the different sounds of dissimilar beacon signals in described second frequency band, the beacon signal of the beacon signal of a described first kind and described second type sends at least once during described the 3rd period.Operation is returned step 1106 from the end of step 1106, and the beacon that for example repeats second base station transmitter in another the 3rd period during in succession the 3rd period of the next one sends.
In some embodiments, for example in communication system for the base station down link that is in diverse location to uplink inter-carrier in each embodiment that changes, execution in step 1108 and 1110.In step 1108, make first base station transmitter periodically in described first frequency band, send the information of indication at the frequency location of a uplink band that in first base station transmit signals, will use.In step 1110, make second base station transmitter periodically in described second frequency band, send the information of indication at the frequency location of a uplink band that in second base station transmit signals, will use.
In some embodiments, for example in communication system downlink carrier to the intercarrier of up link apart from being among each embodiment that fixes, WT according to the BS beacon signaling (for example, step 1104 or 1106) determines a downlink communication frequency band, if therefore know the intercarrier distance of fixing down link to up link, WT just can determine the uplink carrier frequency band, and BS does not need to transmit the broadcasting additional signal.In such embodiments, step 1108 and 1110 can be saved.
In some embodiments, first and second base station transmitters send OFDM (OFDM) signal concurrently on a plurality of sounds during the described first and the 3rd period.
In some embodiments, the described first and the 3rd period respectively comprised it being a plurality of OFDM symbol transmit time segments of 10,000 at least.In some embodiments, each first period comprises at least 16 described second periods.In some embodiments, first has identical length with the 3rd period.In some embodiments, second has identical length with the 4th period.In each embodiment, the first and the 3rd period was called overtime crack, and the second and the 4th period was called beacon slot, and each beacon slot comprises a plurality of symbol transmit time segments.
In some embodiments, the beacon signal of the first kind has the sound of a fixing frequency relation to send with one with sound minimum in the frequency band of the beacon signal that sends the described first kind, and the frequency band that sends first kind beacon signal is a downlink band.In each embodiment, these sounds that are used for sending in the uplink band that the sound of first kind beacon signal and the information that transmits to the base station that sends described first kind beacon signal will use also have a fixing frequency relation.In some embodiments, this is separated from each other uplink band and downlink band frequency band and separates, and is separated by greater than the spacing between the sound in the described downlink band.
In each embodiment, the beacon signal of the first kind has the low or high frequency relation of beacon signal of the every other type that a fixing ratio sends in the frequency band that first kind beacon signal is transmitted into.
In some embodiments, the beacon signal that sends the first kind during each described second period sends at least one beacon signal in described first frequency band to be included in described first period at most once and send the beacon signal at least twice of described second type during described first period.In some embodiments, the beacon signal that sends the first kind during each described the 4th period sends at least one beacon signal in described second frequency band to be included in described the 3rd period at most once and send the beacon signal at least twice of described second type during described the 3rd period.
In each embodiment, a beacon that during each described second period sends at least one beacon signal in described first frequency band to be included in described first period, sends one the 3rd type at least once, and a beacon signal that sends described the 3rd type during each described the 4th period sends at least one beacon signal in described second frequency band to be included in described the 3rd period is at least once.
In some embodiments, the beacon signal of the first kind is a carrier wave beacon signal, is used for transmitting with the base station that sends the carrier wave beacon signal carrying out the relevant information of the used carrier frequency of downlink communication.In each embodiment, the beacon signal of second type is the cell type identifier beacon signal, be sometimes referred to as the slope beacon, transmit the information that sign sends the sub-district of the second type beacon signal, and the beacon signal of the 3rd type, if any, be sectors type identifier beacon signal, the relevant information of base station section that the 3rd type beacon signal is transmitted into the base station transmitter that sends the 3rd type beacon signal is provided.
In each embodiment, first and second base station transmitters are not mutually regularly synchronous, for example are among each embodiment of different districts of diverse geographic location at first and second base station transmitters.In many examples, during a plurality of first periods in succession, make first base station transmitter repeat during first period, to send a plurality of beacon signals, and during a plurality of the 3rd periods that overlap mutually with first period in succession, make second base station transmitter repeat during the 3rd period, to send a plurality of beacon signals.
Technology of the present invention can use the combination of software, hardware and/or software and hardware to realize.The present invention aims to provide the equipment of the present invention of realizing, for example, and the mobile node such as portable terminal, base station, communication system.The present invention also aims to provide certain methods, for example controls and/or operate for example method of main frame of mobile node, base station and/or communication system according to the present invention.The present invention also aims to provide and comprises that being used for controlling a machine makes it realize the machine-readable medium of the machine readable instructions of one or more steps, for example ROM, RAM, CD, hard disk etc. designed according to this invention.
In each embodiment, illustrated here node is to realize with the module of one or more execution and one or more method corresponding steps of the present invention, and these steps for example be signal processing, message generation and/or forwarding step.Therefore, in some embodiments, each functional character of the present invention uses module to realize.Such module can use the combination of software, hardware or software and hardware to realize.Many can the realization by machine-executable instruction such as the software of service recorder on a machine-readable medium such as memory devices such as RAM, floppy disk arranged, for example for example there to be or not have the all-purpose computer realization all or part method discussed above of additional firmware in these methods discussed above or the method step at machine of one or more intranodal controls.Therefore, the present invention mainly is intended to provide make a machine for example processor and associated hardware are carried out the machine-readable medium of machine-executable instruction of one or more steps of method discussed above a kind of comprising.
Though be to describe under the situation of ofdm system, at least some method and apparatus of the present invention can be applicable to far-ranging communication system, comprise many non-OFDM and/or non-cellular system.
To explanation of the present invention, for the person of ordinary skill of the art is conspicuous to many other changes of method and apparatus of the present invention discussed above according to above.Such change should be thought within the scope of the present invention.Method and apparatus of the present invention is passable, and in each embodiment is exactly, and cooperates CDMA, OFDM (OFDM) and/or various other can be used for providing between access node and mobile node the communication technology of wireless communication link to use.In some embodiments, access node is presented as the base station of setting up communication link with OFDM and/or CDMA and mobile node.In each embodiment, mobile node is presented as that the notebook that can realize method of the present invention, personal digital assistant (PDA) or other comprise the portable set of receiver/transmitter circuitry and logic and/or routine.