CN101057422B

CN101057422B - Apparatus and method for transmitting/receiving packet data symbol in a mobile communication system

Info

Publication number: CN101057422B
Application number: CN2005800390181A
Authority: CN
Inventors: 韩臸奎; 裵范植; 权桓准; 金东熙; 金润善; 金唯哲; 郑丁寿; 金大均
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2004-12-03
Filing date: 2005-12-03
Publication date: 2012-09-26
Anticipated expiration: 2025-12-03
Also published as: BRPI0517319B1; JP4510093B2; CN102868658B; JP2008522540A; CN102868658A; KR20060063632A; RU2349032C1; BRPI0517319A; RU2007120632A; CN101057422A

Abstract

An apparatus and method transmits a packet data symbol in a high-rate packet data (HRPD) mobile communication system for broadcasting service. A transmission processor generates a modulated symbol by encoding, interleaving and modulating a physical layer packet to be transmitted, and arranges the modulated symbol in a data tone. A tone inserter inserts a guard tone and a pilot tone into the data tone. A tone power allocator sets a different pilot-to-data tone power ratio according to a position of a slot, in which the packet data symbol is included, and allocates power according to the pilot-to-data tone power ratio. A transmitter transmits the packet data symbol.

Description

Be used for equipment and method at GSM transmission/receiving packet data symbol

Technical field

The present invention relates generally to equipment and the method that is used for providing at radio packet communication system broadcast service.Particularly, the present invention relates to be used for being controlled at the broadcast system that uses Orthodoxy Frequency Division Multiplex (OFDM) transmission plan and control equipment and method the power division of pilot sub-carrier (pilot tone).

Background technology

Traditionally, for receiving on the fixed terminal or on low data rate portable terminal, to be received as target, and developed be used to provide such as broadcast and multicast service (BCMCS) the wireless transmission scheme of broadcast service.Now, allow user (subscriber) to use small-sized terminals to receive the positive research of technical execution of broadcast service at high-speed mobile environment for being used for.Broadcast technology such as DMB (DMB) and hand-held digital video broadcast (DVB-H) (typical B CMCS technology) has developed into and has allowed the user to use the small portable terminal to receive high-quality broadcasting.In addition, DMB and DVB-H technology are studied, so that existing uni-directional broadcast service develops into bidirectional broadcast service.For this reason, considering to use of the plan of existing wire/wireless communication network as Return Channel.But, because broadcasting is used different transmission plans with communicating by letter, so the method is realizing having limitation aspect the bidirectional broadcast.

Usually, radio packet communication system is supported in the communication service of exchange message between specific transmission user and the specific reception user.In this communication service, different received user is through different channel receiving informations.But owing to the interchannel interference that the isolation of its lower channel and channel causes, radio packet communication system suffers mis-behave.In order to increase the isolation of channel and channel, current GSM uses honeycomb notion and the multiple access (rdma) scheme such as Code Division Multiple Access (CDMA), time-division multiple access (TDMA) (TDMA), frequency division multiple access (FDMA).But,, can not remove interference fully even use these technology.

Different with communication service, the BCMCS service allows to transmit user's uniaxially information is sent to a plurality of reception users.Because they share identical channel, so, between the user who receives identical information, do not disturb.But, because the multipath that in the environment of high-speed mobile, takes place (multipath) decline, so the mobile broadcast service suffers mis-behave.In order to solve (address) this problem, be designed to support that the broadcast system of the mobile reception such as digital video broadcast terrestrial (DVB-T), DVB-H and digital audio broadcasting (DAB) system uses the OFDM transfer scheme.

In broadcast system, use the OFDM transfer scheme can prevent from causing from the multipath fading that disturbs.Particularly, in broadcast service, different base stations transmits identical broadcast singal via Single Frequency Network (SFN).Therefore, the OFDM transfer scheme has following advantage, that is, it can prevent the interference between the broadcast singal that is transmitted by different base station.Therefore, the OFDM transfer scheme is applied to broadcast service can realizes noiseless environment, thereby make contributions for the maximization of communication efficiency.

The down link of HRPD (HRPD) GSM uses TDMA as multiple access (rdma) scheme, and uses time division multiplexing/code division multiplex (TDM/CDM) as multiplexing scheme.

Fig. 1 is the figure that is illustrated in time slot (slot) form of the down link in traditional HRPD GSM.

Graphic like Fig. 1 institute, a time slot has the form that repeats with half time slot.To have N _PilotThe

pilot tone

103 and 108 of leaf length is inserted in the central authorities in half crack, and, the channel estimating that said

pilot tone

103 and 108 is used at the down link of receiving terminal.Transmit at the two ends of

pilot tone

103 and 108 comprise uplink power control information and resource allocation information, have a N _MACMedia interviews control (MAC) information 102,104,107 and 109 of leaf length.Before MAC information 102,104,107 and 109 and transmit afterwards and have N _DataThe actual transmissions data 101,105,106 and 110 of leaf length.In this way, come pilot tone, MAC information, real data are carried out time division multiplexing through TDM.

Through CDM, utilize walsh codes and MAC and data message are carried out multiplexed, and in the HRPD downlink system, the length of pilot tone, MAC and data block is set to N _Pilot=96, N _MAC=64 and N _Data=400.

The figure of Fig. 2 time slot format that to be diagram provide through the transfer of data that the OFDM code element is inserted into the HRPD downlink time slots that is used for the BCMCS service at interval.

Compatible to the HRPD down link, the position of pilot tone and MAC signal and big or small and be complementary shown in figure 2 in the position and the size of pilot tone shown in Fig. 1 and MAC signal.Just, will have N _PilotThe

pilot tone

103 and 108 of leaf length places the central authorities of half time slot, and will have N _MACThe MAC signal 102,104,107 and 109 of leaf length places the both sides of pilot signal 103 and 108.Therefore, yet can not estimate channel and receive the MAC signal based on the existing HRPD terminal of the broadcast service of OFDM even do not support through pilot tone.OFDM code element 121,122,123 and 124 is inserted in all the other fields (that is, the transfer of data interval 101,105,106 and 110) of time slot.Provide OFDM code element 121,122,123 and 124 through modulation BCMCS information.

At N _DataIn=400 the existing HRPD downlink system, the size of OFDM code element is set to N _Data=400.The OFDM scheme is arranged in the head of each OFDM code element with Cyclic Prefix (CP), is caused from disturbing by the reception signal of time delay owing to multipath fading so that prevent.Just, an OFDM code element comprises CP 125 and the OFDM data 126 through the anti-FFT of BCMCS information and executing (IFFT) is generated.The size of CP 125 is N _CPSheet, and, for CP 125, duplicate N at OFDM data 126 afterbodys _CPThe sheet signal is arranged in it head of OFDM data 126 then.Therefore, the size of OFDM data 126 becomes (N _Data-N _CP) sheet.At this, caused from the time delay of disturbing according to what allow, confirm N _CPN _CPIncrease just increased by the number of the delayed reception signal of demodulation, and do not disturb, still because the minimizing of OFDM size of data has reduced transmissible amount of information.Yet, N _CPMinimizing increased transmissible amount of information, still because high interference possibility in serious multipath fading environments has reduced the quality of reception.

In SFN, because on the terminal, receive the same signal that transmits by several terminals, so the size of CP is set to higher value usually at different time.Be used for the HRPD downlink system of the ofdm signal of BCMCS service in transmission, preferably, with N _CPBe set to 80 (N _CP=80).In this case, the size of OFDM data becomes 320.This expression can be carried out IFFT to 320 modulated symbols, and in OFDM transfer of data interval, transmits the code element after IFFT handles.Therefore, through the OFDM scheme, can obtain 320 number of sub-carrier (tone) altogether.

But, be not that whole 320 number of sub-carrier can both be used for transmission of data symbols.Some subcarriers that are positioned at employed band edge should be used as: be used to prevent that out of band signal from becoming the protection subcarrier of interference.Because before transmitting, using different sign indicating numbers to expand the

pilot tone

103 and 108 that (spread) uses on the different conveyers in existing HRPD down link, so, the channel estimating that the BCMCS that they are not suitable in SFN, providing serves.The dedicated pilot that therefore, additionally need be used for the channel estimating of ofdm signal.Can use the part of subcarrier to be transmitted in predefined signal between conveyer and the receiver, should be used for channel estimating by predefined signal then, and, such subcarrier is called OFDM dedicated pilot subcarrier.The OFDM scheme of in SFN, using allows long relatively time delay, thereby causes serious frequency-selecting decline (frequency-selective fading).Therefore, even need under the situation of serious frequency-selecting decline, also can guarantee that pilot sub-carrier is enough to carry out channel estimating.

Fig. 3 is the figure that is illustrated in the traditional subcarrier permutation method in the HRPD system.

With reference to figure 3, protection subcarrier 201 is arranged in the edge of frequency band.With the low frequency part of 8 protection subcarrier permutation in 16 protection subcarriers at frequency band, and with the HFS of all the other 8 protection subcarrier permutation at frequency band.Obstructed overprotection subcarrier transmits signal, so, power is not provided to the protection subcarrier.Data subcarrier 203 is arranged in the central authorities of frequency band.At last, because pilot sub-carrier 202 is used for channel estimating, so, arrange pilot sub-carrier 202 with the interval clocklike of per 5 number of sub-carrier.Arrangement of subcarrier promptly, is being followed the pilot sub-carrier that is arranged on the low-limit frequency after four protection subcarriers, and then is being inserted pilot sub-carrier in this way.

Similarly; Even in the field of having arranged data subcarrier 203, also insert pilot sub-carrier 202, then, following pilot sub-carrier 202 after four data subcarriers 203; And, new pilot sub-carrier 202 is arranged in after these four data subcarriers 203.In this way, pilot sub-carrier 202 is arranged on the frequency corresponding to direct current (DC) component.Because pilot sub-carrier 202 is DC subcarriers, so, before transmission, do not distribute power or distribute low-power to them to them.

Pilot sub-carrier 202 and data subcarrier 203 are different each other aspect the power that is assigned with.The power that is assigned to pilot sub-carrier 202 should pass through conveyer and receiver predefine to the preferred plan of the ratio of the power that is assigned to data subcarrier 203, and this is because said beguine it is believed that condition and difference.

Fig. 4 is the block diagram that is illustrated in the structure of the traditional conveyer in the HRPD system.

With reference to figure 4, conveyer comprise be used for to the grouped data that is received carry out chnnel coding channel encoder 301, be used for to coding the channel interleaver 302, the modulator 303 that is used to modulate the grouped data that interweaves that interweave of grouped data, be used to insert the protection subcarrier inserter 304 of protection subcarrier and the pilot sub-carrier inserter 305 that is used to insert pilot sub-carrier.In addition, conveyer comprises sub-carrier power distributor 306, quaternary PSK (QPSK) expander (spreader) 307, IFFT unit 308, CP inserter 309, and HRPD compatible processor 310.

The physical layer packet data that will in the upper strata, generate are input to channel encoder 301.Channel encoder 301 is encoded to the bit stream of chnnel coding with this Packet Data Channel, and the bit stream of this chnnel coding is outputed to channel interleaver 302.Channel interleaver 302 interweaves the bit stream (or to its carry out column permutation (column permutation)) of this chnnel coding obtaining diversity gain, and the bit stream that will interweave outputs to modulator 303.The bit stream that modulator 303 will interweave is modulated to modulation signal.This modulation signal is arranged in the data subcarrier 203.

Protection subcarrier inserter 304 will be arranged in the protection subcarrier 201 that is arranged in band edge from the signal of modulator 303 outputs; And pilot sub-carrier inserter 305 is clocklike to be arranged in pilot sub-carrier 202 from the signal of protection subcarrier inserter 304 outputs at interval.Afterwards, sub-carrier power distributor 306 distributes power according to the ratio R of the power that is assigned to pilot sub-carrier to the power that is assigned to data subcarrier.In QPSK expander 307, after being assigned to whole subcarriers, transmission signals is carried out the QPSK expansion.In the QPSK extension process, the base station signal that will be used to transmit different BCMCS contents multiply by different multiple pseudo noise (PN) sequences.Multiple PN sequence representes that real component and imaginary component all comprise the complex sequences of PN sign indicating number.

Because on receiver, undesired base station signal possibly become noise component(s), so receiver can be carried out the channel estimating of separating with undesirable base station to channel.Identifier according to the BCMCS content of importing is created on the multiple PN sequence of using in the QPSK extension process.

In IFFT unit 308, handle and at the modulation signal of the positional alignment QPSK expansion of the frequency sub-carrier of hope through IFFT.Afterwards, CP inserter 309 is inserting CP from the signal of IFFT unit 308 output, so that prevent the interference certainly that causes owing to multipath fading, thus the generation of completion OFDM transmission signals.Afterwards, HRPD compatible processor 310 continues to carry out the HRPD transmission process, to insert

pilot tone

103 and 108 and MAC information 102,104,107 and 109.The final signal that transmits has time slot format shown in figure 2.

Through with reference to figure 5A and Fig. 5 B, will be made in the description of the form that transmits OFDM BCMCS time slot between the CDM time slot now.Fig. 5 A is the figure that is illustrated in the form that transmits OFDM BCMCS time slot between the CDM time slot.Here, this CDM time slot has at the time slot format shown in Fig. 1, and, in its data field, comprise the signal that CDM is multiplexed.OFDM BCMCS time slot has time slot format shown in figure 2.

Through with reference to figure 5A, will make description now to the channel estimation process of each the OFDM code element on the terminal that receives the OFDMBCMCS time slot 402 that transmits between

CDM time slot

401 and 403.

OFDM BCMCS time slot 402 comprises 4 OFDM code elements 121,122,123 and 124

wherein.Reference numeral

121 and 124 indications are positioned at the OFDM code element of time slot edge, and Reference numeral 122 and 123 indications are positioned at the OFDM code element of time slot central authorities.

Usually, make channel can in the OFDM code element, do not changed because the length of OFDM code element confirmed as, so the channel-changing between adjacent OFDM code element is not remarkable.Therefore, the OFDM code element that is positioned at time slot central authorities can be used the pilot sub-carrier of edge OFDM code element, so that estimate channel.For example, the not only pilot sub-carrier of OFDM code element 122, and

OFDM code element

121 and 123 pilot sub-carrier are used to the channel of estimating OFDM code element 122, thereby improve channel estimating performance.

Yet in channel estimation process, the OFDM code element that is arranged in time slot edge has limitation at the pilot sub-carrier that uses adjacent OFDM code element.More specifically, the pilot sub-carrier that is used for the channel of estimating OFDM code element 121 comprises the pilot sub-carrier of OFDM code element 121 and the pilot sub-carrier of OFDM code element 122.This be because: owing to before the transmission of OFDM code element 121, transmitted CDM time slot rather than BCMCS time slot, estimate so there is pilot sub-carrier will be used to signal.Therefore, be positioned at the central

OFDM code element

122 and 123 of OFDM BCMCS time slot is superior to being positioned at OFDM BCMCS time slot edge aspect channel estimating performance OFDM code element 121 and 124.This is because do not consider power that the position of OFDM code element, identical value be used to the to be assigned to independent pilot sub-carrier ratio R to the power of the power that is assigned to independent data subcarrier.

As a result, compare with the OFDM code element that is positioned at OFDM BCMCS time slot central authorities, the OFDM code element that is positioned at time slot edge has the higher reception mistake possibility during the transfer of data of occurring in.

As shown in Fig. 5 B, even when OFDM BCMCS time slot transmits continuously, this phenomenon also can take place.Reference numeral 405,406 is all represented the OFDM BCMCS time slot that transmits different broadcast messages with 407.The terminal that receives the broadcast message of OFDM BCMCS time slot 406 need not receive OFDM BCMCS time slot 405 and 407.Therefore, even under the situation that transmits OFDM BCMCS time slot continuously, receive wrong possibility still can according to the OFDM code element the position and inequality.

Summary of the invention

Therefore, an object of the present invention is, be provided for improving equipment and method based on the receptivity in the HRPD GSM of OFDM transmission plan.

Another object of the present invention is, is provided in based on the HRPD GSM of OFDM transmission plan regulating and distributing according to the position of OFDM code element the equipment and the method for the power of pilot sub-carrier.

According to an exemplified aspect of the present invention, provide be used for the equipment that the HRPD of broadcast service (HRPD) GSM transmits packet data symbol.This equipment comprises transmission processor, is used for through coding, interweaves and modulate the physical layer packet that will transmit, and generate the code element of modulation, and in data subcarrier, arrange the code element of modulating; The subcarrier inserter is used for protection subcarrier and pilot sub-carrier are inserted into data subcarrier; The sub-carrier power distributor is used for different pilot being set according to the sub-carrier power ratio according to the position of time slot, and distributes power according to pilot according to the sub-carrier power ratio, wherein, in said time slot, comprises packet data symbol; And conveyer, be used to transmit packet data symbol.

According to another exemplified aspect of the present invention, provide be used for the method that the HRPD of broadcast service (HRPD) GSM transmits packet data symbol.This method may further comprise the steps: through coding, interweave and modulate the physical layer packet that will transmit, and generate the code element of modulation, and in data subcarrier, arrange the code element of modulating; To protect subcarrier and pilot sub-carrier to be inserted in the data subcarrier; Position according to time slot is provided with different pilot according to the sub-carrier power ratio, and distributes power according to pilot according to the sub-carrier power ratio, wherein, in said time slot, comprises packet data symbol; And transmission packet data symbol.

According to another exemplified aspect of the present invention, provide in the method that is used for the HRPD of broadcast service (HRPD) GSM receiving packet data symbol.This method may further comprise the steps: receiving about according to the position of transmitting packet data symbol and definite pilot during according to the information of sub-carrier power ratio, storage according to the pilot of element position according to the sub-carrier power ratio; If being Orthodoxy Frequency Division Multiplex (OFDM), the grouping that receives divides into groups, then from this OFDM extract data symbols, and the data symbols extracted of despreading (despread), thereby extract data subcarrier and pilot sub-carrier; The pilot of using the OFDM grouping is estimated channel according to the sub-carrier power ratio; And use channel estimating information, from the data subcarrier restore data.

According to another exemplified aspect of the present invention, provide at the equipment that is used for the HRPD of broadcast service (HRPD) GSM receiving packet data symbol.This equipment comprises: channel estimating unit, be used for receiving control message, and extract pilot according to the position of packet data symbol according to the sub-carrier power ratio, confirm the channel estimating weighting, and estimate channel according to the sub-carrier power ratio according to pilot; Orthodoxy Frequency Division Multiplex (OFDM) processor is used for the OFDM code element that is received is divided into pilot sub-carrier and data subcarrier, and pilot sub-carrier is provided to channel estimating unit, and the dateout subcarrier; And data recovery unit, be used to use the channel estimating information that provides from channel estimating unit, recover the information that is transmitted from data subcarrier.

Description of drawings

When combining accompanying drawing from the description of following mask body, above and other illustrative purpose of the present invention, feature and advantage will become clearer, in the accompanying drawings, will understand, identical Reference numeral is represented identical part, element and structure, wherein:

Fig. 1 is the figure that is illustrated in the time slot format of the down link in traditional HRPD GSM;

The figure of Fig. 2 time slot format that to be diagram provide through the transfer of data that the OFDM code element is inserted into the HRPD downlink time slots that is used for the BCMCS service at interval;

Fig. 3 is the figure that is illustrated in the traditional subcarrier permutation method in the HRPD system;

Fig. 4 is the block diagram that is illustrated in the structure of the traditional conveyer in the HRPD system;

Fig. 5 A is the figure that is illustrated in the form that transmits OFDM BCMCS time slot between the CDM time slot;

Fig. 5 B is the figure that is illustrated in the form that transmits OFDM BCMCS time slot between the OFDM BCMCS time slot;

Fig. 6 is diagram according to exemplary embodiment of the present invention, at the block diagram of the structure of the HRPD system conveyer that is used for broadcast service;

Fig. 7 is diagram according to exemplary embodiment of the present invention, at the flow chart of the operation of the conveyer of the HRPD system that is used for broadcast service;

Fig. 8 is diagram according to exemplary embodiment of the present invention, at the flow chart of the operation of the receiver of the HRPD system that is used for broadcast service;

Fig. 9 is the figure that is illustrated in the exemplary time slot format that transmits OFDM BCMCS time slot between the CDM time slot continuously;

Figure 10 is diagram according to another exemplary embodiment of the present invention, at the flow chart of the operation of the conveyer of the HRPD system that is used for broadcast service;

Figure 11 is diagram according to another exemplary embodiment of the present invention, at the flow chart of the operation of the receiver of the HRPD system that is used for broadcast service;

Figure 12 be diagram according to an embodiment of the invention, be used to receive the block diagram of structure that position according to the OFDM code element is provided with the receiver of the ofdm signal that conveyer transmits after the different power ratio; And

Figure 13 be diagram according to an embodiment of the invention, receive the flow chart of the processing of ofdm signal on the receiver in the HRPD system.

Embodiment

Now, will specifically describe several exemplary embodiment of the present invention with reference to accompanying drawing.In the accompanying drawings, as already pointed out, even in different drawings, describe them, also represent identical or close element by identical Reference numeral.In the following description, in order to know and for simplicity, to have omitted in the known function of this merging and the specific descriptions of configuration.

Use can with the system of the compatible OFDM transmission plan of HRPD in, may not transmit the BCMCS time slot continuously.Therefore, channel estimating performance depends on whether the OFDM code element is positioned at time slot edge or time slot central authorities.The OFDM code element that is positioned at time slot edge aspect channel estimating performance inferior to the OFDM code element that is positioned at time slot central authorities.Just, because do not consider power that the position of OFDM code element, identical value be used to be assigned to independent pilot sub-carrier ratio R, so the wrong possibility that is positioned at the OFDM code element of time slot edge increases to the power of the power that is assigned to independent data subcarrier.

Therefore, exemplary embodiment of the present invention provides the method that regulates and distributes the power of pilot sub-carrier according to the position of time slot, thereby has improved receiving ability.

Usually, the increase of the power of pilot sub-carrier improves channel estimating performance.But, because define overall transmission power, so the increase of pilot sub-carrier power causes the minimizing of data subcarrier power as pilot sub-carrier power and data subcarrier power.The minimizing of data subcarrier power causes the increase of wrong possibility in data decode is handled.Therefore, for given overall transmission power, need be assigned to the power of pilot sub-carrier and be assigned to compromise between the power of data subcarrier.

In operation, should in the transmission interval, be predefined in the power ratio R_Side of the OFDM code element use that is positioned at time slot edge and the power ratio R_Center that uses in the OFDM code element that is being positioned at time slot central authorities.For power ratio R_Side and R_Center, their initial value or this value of before receiving the BCMCS time slot, notifying from the base station can be used in the terminal.Just, because best R_Side and R_Center value be according to channel conditions and different, so, in transmission these values of predefine in the time period.In the rapid fading environment, because use the channel estimating of the pilot sub-carrier execution of in another code element, using to show low reliability, so preferably R_Side and R_Center are set to higher as much as possible value.

Fig. 6 is diagram according to exemplary embodiment of the present invention, at the block diagram of the structure of the HRPD system conveyer that is used for broadcast service.

Conveyer comprise be used for to the grouped data that is received carry out chnnel coding channel encoder 301, be used for to coding the channel interleaver 302, the modulator 303 that is used to modulate the grouped data that interweaves that interweave of grouped data, be used for the protection subcarrier is inserted into from the protection subcarrier inserter 304 of the signal of modulator 303 outputs, and be used for pilot sub-carrier is inserted from the pilot sub-carrier inserter 305 of the signal of protection subcarrier inserter 304 outputs.In addition, conveyer comprises sub-carrier power distributor 606, QPSK expander 307, IFFT unit 308, CP inserter 309, and HRPD compatible processor 310.

The operation of conveyer is described referring now to Fig. 6 particularly.

The physical layer packet data that will in the upper strata, generate are input to channel encoder 301.Channel encoder 301 is encoded to the bit stream of chnnel coding with this Packet Data Channel, and the bit stream of this chnnel coding is outputed to channel interleaver 302.The interweave bit stream (or to its carry out rank transformation) of this chnnel coding of channel interleaver 302, realizing diversity gain, and the bit stream that will interweave outputs to modulator 303.The bit stream that modulator 303 will interweave is modulated to modulation signal.This modulation signal is arranged in the data subcarrier 203.

Protection subcarrier inserter 304 will be arranged in the protection subcarrier 201 that is arranged in band edge from the signal of modulator 303 outputs; And pilot sub-carrier inserter 305 is clocklike to be arranged in pilot sub-carrier 202 from the signal of protection subcarrier inserter 304 outputs at interval.

Afterwards, sub-carrier power distributor 606 regulates and distributes the power of pilot sub-carrier according to the element position (just, whether corresponding OFDM code element is positioned at time slot edge or time slot central authorities) of correspondence.This will more specifically describe with reference to figure 5A.For the

OFDM code element

121 and 124 that is positioned at time slot edge, use power ratio R_Side to divide the power that is used in pilot sub-carrier and data subcarrier.For the

OFDM code element

122 and 123 that is positioned at time slot central authorities, use power ratio R_Center to distribute the power of pilot sub-carrier and data subcarrier.As stated, in exemplary realization, predefine R_Side and R_Center value.

In QPSK expander 307, after being assigned to whole subcarriers, transmission signals is carried out the QPSK expansion.IFFT unit 308 is handled through IFFT and in the position of the frequency sub-carrier of hope, is arranged the modulation signal of QPSK expansion.Afterwards, CP inserter 309 is inserting CP from the signal of IFFT unit 308 outputs, thereby accomplishes the generation of OFDM transmission signals.

Exemplary embodiment of the present invention is provided with variable pilot according to sub-carrier power ratio (that is, variable pilot sub-carrier power is to the ratio of data sub-carrier power) according to the position of OFDM code element.But replacedly, the ad-hoc location that also can be the OFDM code element is provided with fixing power ratio.According to exemplary embodiment of the present invention, because maybe not can transmit the OFDM code element, so the HRPD system uses variable power ratio and the power ratio of on-fixed at whole time slots.

The power ratio of on-fixed in order to use variable power ratio; The base station (for example will be sent to the signaling message that is used for supporting the BCMCS service in the HRPD system about the information based on the power ratio of the position of OFDM code element; Air broadcast (BroadcastOverhead) message) terminal is to notify current pilot according to the sub-carrier power ratio to the terminal.

In order pilot to be set changeably, can consider following two exemplary embodiments according to the sub-carrier power ratio.

In first embodiment, the base station provides to the terminal has the information of indication pilot according to the sub-carrier power ratio, and the time slot that usually transmits the OFDM code element therein provides this pilot according to the sub-carrier power ratio.The form of signaling message at the terminal of the general power ratio of notice in first embodiment of using the base station has been shown in table 1.

Table 1

Field	Length (bit)
		[...]	[...]
DualPDREnabled	1
		EBCMCSTransmissionFormat	0 or
	N
		DCPilotToDataGain	0 or N
DualPDREnabledForThisLogicalChannelDualPDREnabled
		1
ACPilotToDataGainRecord			0, N, 2N, or 4N
	[...]	[...]

Table 1 only shows the field of in exemplary embodiment of the present invention, using, and has omitted other field that is used to support the BCMCS service.To be configured to indicate two types the pilot of code element according to the sub-carrier power ratio at the signaling message shown in the table 1.Suppose on 1 time slot, to transmit 4 OFDM code elements, so, the HRPD system can indicate the pilot that is used for each OFDM code element according to the sub-carrier power ratio.But, because the property class of two code elements that are positioned at time slot central authorities and two code elements that are positioned at time slot edge is seemingly, so pilot is indicated as the load that can reduce signaling message according to the sub-carrier power ratio.Below will be described in each field of the signaling message shown in the table 1.

" DualPDREnabled " field has indicated whether to use two types the pilot sub-carrier power of code element to the ratio (double pilot is to data sub-carrier power ratio (two PDR (DualPDR))) of data sub-carrier power.If this field value is set to " 1 ", then two PDR have been used in its expression.But if this field value is set to " 0 ", the pilot of then representing only to have used the code element that is used for a type is according to the sub-carrier power ratio.

" EBCMCSTransmissionFormat " field indication transformat.If the highest significant position of this field (MSB) is set to " 0 ", then the transformat of not supporting variable format has been used in expression.But if the MSB of this field is set to " 1 ", then the transformat of supporting variable format has been used in expression.When transmitting a plurality of time slot, variable format allows each independent time slot to transmit the OFDM code element with other form.According to exemplary embodiment of the present invention, the formal definition that will be used for the OFDM code element of variable format is the number of the size of CP, pilot sub-carrier and the number of protection subcarrier.Just, when supporting variable format, possibly transmit the OFDM code element for each independent time slot, wherein, CP, pilot sub-carrier and the protection subcarrier that will all have different sizes (or length) are applied to said OFDM code element.Therefore, the suitable PDR value of independent time slot maybe be different.When reason is supported variable format for this reason, different PDR values need be set before or after change of format.

" DCPilotToDataGain " field indication DC pilot sub-carrier power is to the ratio (that is, the DC pilot is according to the sub-carrier power ratio) of data sub-carrier power.In first exemplary embodiment of the present invention, because hypothesis only is applied to interchange (AC) pilot sub-carrier with two PDR, so, define single DCPILOTTODATAGAIN value.

Whether the corresponding logic channel of " DualPDREnabledForThisLogicalChannel " field indication comprises two PDR.If this field value is set to " 1 ", then corresponding logic channel uses two PDR, and its indication will define the field about two PDR through this field.But if this field value is set to " 0 ", then the corresponding logic channel of expression does not use two PDR.

" ACPilotToDataGainRecord " field indication AC pilot sub-carrier power is to the ratio (that is, the AC pilot is according to the sub-carrier power ratio) of data sub-carrier power.If " DualPDREnabledForThisLogicalChannel " field is set to " 0 ", then two PDR are not used in indication, to represent " ACPilotToDataGainRecord " field at the form shown in table 2A or the table 2B.

Table 2A

Field	Length (bit)
		ACPilotToDataGain	N

Table 2B

Field	Length (bit)
		ACPilotToDataGain1	N
ACPilotToDataGain2	N

Table 2A shows AC pilot for the situation of not using variable format according to the sub-carrier power ratio, and table 2B shows AC pilot for the situation of using variable format according to the sub-carrier power ratio.

Table 2A shows when " DualPDREnabledForThisLogicalChannel " field and is set to MSB in " 0 " and " EBCMCSTransmissionFormat " field when being set to " 0 "; When just not using two PDR and variable format, how to represent " ACPilotToDataGainRecord " field." ACPilotToDataGain " field indication AC pilot is according to the sub-carrier power ratio, and do not consider the position of corresponding code element and be identical value with " ACPilotToDataGain " Field Definition.

Table 2B shows when " DualPDREnabledForThisLogicalChannel " field and is set to MSB in " 0 " and " EBCMCSTransmissionFormat " field when being set to " 1 "; When just having used variable format, how to represent " ACPilotToDataGainRecord " field less than using two PDR." ACPilotToDataGain1 " field indication before transformat changes the AC pilot according to the sub-carrier power ratio; And " ACPilotToDataGain2 " field indication after transformat changes the AC pilot according to the sub-carrier power ratio, and do not consider correspondence code element the position and be identical value with " ACPilotToDataGain2 " Field Definition.

If " DualPDREnabledForThisLogicalChannel " field is set to " 1 ", thereby two PDR are used in indication, then to represent " ACPilotToDataGainRecord " field at the form shown in table 2C or the 2D.

Table 2C

Field	Length (bit)
		ACInternalPilotToDataGain	N
ACBoundaryPilotToDataGain	N

Table 2D

Field	Length (bit)
		ACInternalPilotToDataGain1	N
ACBoundaryPilotToDataGain1	N
		ACInternalPilotToDataGain2	N
ACBoundaryPilotToDataGain2	N

Table 2C shows AC pilot for the situation of not using variable format according to the sub-carrier power ratio, and table 2D shows AC pilot for the situation of using variable format according to the sub-carrier power ratio.

Table 2C shows when " DualPDREnabledForThisLogicalChannel " field and is set to MSB in " 1 " and " EBCMCSTransmissionFormat " field when being set to " 0 "; Just use two PDR and when not using variable format, how to represent " ACPilotToDataGainRecord " field." ACInternalPilotToDataGain " field comprises the value of the pilot of the central code element that is used for being transmitted in the OFDM code element that transmits on the time slot according to the sub-carrier power ratio, and " ACBoundaryPilotToDataGain " field comprises the value of the pilot of the edge code element that is used for being transmitted in the OFDM code element that transmits on the time slot according to the sub-carrier power ratio.

Table 2D shows when " DualPDREnabledForThisLogicalChannel " field and is set to MSB in " 1 " and " EBCMCSTransmissionFormat " field when being set to " 1 "; When just using two PDR and variable format, how to represent " ACPilotToDataGainRecord " field.The pilot that " ACInternalPilotToDataGain1 " field and " ACBoundaryPilotToDataGain1 " field comprise the central code element that is used for being transmitted in the OFDM code element that transmits on the time slot respectively according to the value of sub-carrier power ratio and the pilot of edge code element that is used for being transmitted in the OFDM code element that transmits on the time slot according to the value of sub-carrier power ratio, and before transformat changes, be used.

The pilot that " ACInternalPilotToDataGain2 " field and " ACBoundaryPilotToDataGain2 " field comprise the central code element that is used for being transmitted in the OFDM code element that transmits on the time slot respectively according to the value of sub-carrier power ratio and the pilot of edge code element that is used for being transmitted in the OFDM code element that transmits on the time slot according to the value of sub-carrier power ratio, and after transformat changes, be used.

In second exemplary embodiment, the base station provides to the terminal has the indication pilot according to the information of sub-carrier power ratio, wherein, interweaves separately for each at the time slot that transmits the OFDM code element and to use said pilot according to the sub-carrier power ratio.HRPD system with the operation of 4 time slot interleaving transmission plans can use only one or a plurality of interweaving for the transmission of OFDM code element.Therefore, between OFDM code element transmission period, the HRPD system can be provided with different pilot according to the sub-carrier power ratio for each interweaves separately.

The form of the signaling message that uses the base station in second embodiment has been shown in table 3, and it is in order to be used for each variable pilot that interweaves separately according to the sub-carrier power ratio to the terminal notice between OFDM code element transmission period.

Table 3

Field	Length (bit)
		[...]	[...]
PilotToneToDataTonePowerRa tioIncluded	1
		[...]	[...]
Interlace0Included	1
		CenterSymbolsPTDTPR0	0 or N
SideSymbolsPTDTPR0	0 or N
		[...]	[...]
Interlace1Included	1
		CenterSymbolsPTDTPR1	0 or N
SideSymbolsPTDTPR1	0 or N
		[...]	[...]
Interlace2Included	1
		CenterSymbolsPTDTPR2	0 or N
SideSymbolsPTDTPR2	0 or N
		[...]	[...]
Interlace3Included	1
		CenterSymbolsPTDTPR3	0 or N
SideSymbolsPTDTPR3	0 or N
		[...]	[...]

Table 3 only shows the field that is used at embodiments of the invention, and omitted the field that other is used to support the BCMCS service.To be configured to comprise that the pilot of indicating the code element that is used for two types is according to the sub-carrier power ratio at the signaling message shown in the table 3.

Signaling message can comprise and is used to indicate the field of the pilot of each code element according to the sub-carrier power ratio.But as shown in table 3, signaling message comprises the field of the pilot of the code element that is used to indicate two types according to the sub-carrier power ratio, so that reduce the load of signaling message.

To specifically describe each field of the signaling message shown in the table 3 now below.

" PilotToneToDataTonePowerRatioIncluded " field has indicated whether to comprise the value of pilot sub-carrier to data sub-carrier power ratio.If this field value is set to " 0 ", then expression does not comprise pilot sub-carrier to data sub-carrier power ratio, and uses default value.But if this field value is set to " 1 ", then expression has comprised that the pilot sub-carrier that between the transmission period of whole OFDM code elements, uses is to data sub-carrier power ratio.

" InterlaceXIncluded " field has indicated whether to comprise will use " X " that interweaves and the information that transmits.Here, X representes 0,1,2 or 3.If this field value is set to " 0 ", then expression does not comprise transmission information, and if this field value is set to " 1 ", then expression comprises transmission information.

" CenterSymbolsPTDTPRX (the pilot sub-carrier power of the central code element that in the X time slot that interweaves, transmits to data sub-carrier power ratio, wherein X=0,1,2 or 3) " field comprises that the pilot that is used in the transmission that transmits the central code element among the OFDM code element on the time slot that InterlaceX comprises is according to the sub-carrier power rate value.Only be set to " 1 " and " InterlaceXIncluded " field when being set to " 1 " when " PilotToneToDataTonePowerRatioIncluded " field, just comprise " CenterSymbolsPTDTPRX " field.

The indication of " SideSymbolsPTDTPRX (the pilot sub-carrier power of the limit code element that in the X time slot that interweaves, transmits to the ratio of data sub-carrier power, wherein X=0,1,2 or 3) " field be used for being transmitted in transmit the code element (sidesymbols) on the limit in the OFDM code element on the time slot that Interlace X comprises pilot according to the sub-carrier power rate value.Only be set to " 1 " and " InterlaceXIncluded " field when being set to " 1 " when " PilotToneToDataTonePowerRatioIncluded " field, just comprise " SideSymbolsPTDTPRX " field.

Be used to indicate the value of pilot at table 1 to the N shown in the table 3 according to the sub-carrier power ratio.Can dB represent this value or can be, and its resolution can be depending on the size of N to its coding before transmission.

With reference to figure 7, with make according to exemplary embodiment of the present invention, be used for position according to the OFDM code element be transmission time slot set different pilot according to the sub-carrier power rate value, make the specific descriptions of operation of conveyer of the value that on the position of specific OFDM code element, can always use the constant power ratio.

Fig. 7 is diagram according to exemplary embodiment of the present invention, at the flow chart of the operation of the conveyer of the HRPD system that is used for broadcast service.In exemplary embodiment of the present invention, be called the base station at the conveyer of the HRPD system that is used for broadcast service.

In step 701, conveyer uses channel encoder 301, channel interleaver 302 and modulator 303, generates data subcarrier according to the broadcast data that will transmit.In step 702, will protect subcarrier to be inserted in the data subcarrier, and, in step 703, pilot sub-carrier is inserted in the data subcarrier that inserts the protection subcarrier.In step 704, conveyer confirms that corresponding OFDM code element is positioned at the central authorities of time slot or the edge of time slot.If confirm that the OFDM code element is positioned at time slot edge, then in step 705, conveyer arrives pilot sub-carrier and data subcarrier according to power ratio R_Side with power division.But if confirm that the OFDM code element is positioned at time slot central authorities, then in step 706, conveyer arrives pilot sub-carrier and data subcarrier according to power ratio R_Center with power division.

Afterwards, in step 707, conveyer uses QPSK expander 307, carries out different QPSK expansions according to the BCMCS content designator.In step 708, conveyer uses IFFT unit 308 to carry out I FFT and handles, and uses CP inserter 309 that CP is inserted in the code element after IFFT handles, thereby accomplishes ofdm signal.Afterwards, conveyer uses HRPD compatible processor 310 to carry out the HRPD compatible processing in step 709, and in step 710, transmits the ofdm signal of accomplishing.

With reference to figure 8, recover the description of the exemplary process of broadcast singal in the time of will making the ofdm signal that generates when the operation that receives through Fig. 7 now, at receiver.

Fig. 8 is diagram according to exemplary embodiment of the present invention, at the flow chart of the operation of the receiver of the HRPD system that is used for broadcast service.In exemplary embodiment of the present invention, be called the terminal at the receiver of the HRPD system that is used for broadcast service.

In step 801, receiver receives R_Side and the R_Center value from base station or conveyer.When receiving the failure of R_Side and R_Center value, receiver uses initial R_Side and R_Center value.When receiving the BCMCS time slot, receiver extracts the OFDM code element from the BCMCS time slot that is received in step 802, and in step 803, the OFDM code element of being extracted is carried out the QPSK despreading.

Afterwards, in step 804, receiver is carried out channel estimating, and whether definite OFDM code element is positioned at time slot edge.If the OFDM code element that is received is positioned at time slot edge, then receiver advances to step 805, and wherein, it carries out channel estimating according to pilot according to sub-carrier power ratio R _ Side.

But if confirm that the OFDM code element is positioned at time slot central authorities, then receiver advances to step 806, and wherein, it carries out channel estimating according to pilot according to sub-carrier power ratio R _ Center.In the channel estimation process of step 805 and 806, receiver uses the pilot sub-carrier that is positioned at adjacent OFDM code element.In step 807, receiver extracts data subcarrier from estimated channel, and the data subcarrier that extracts of demodulation.In step 808, receiver is the broadcast singal of demodulated data subcarrier decoding for transmitting from conveyer the most at last.

Hypothesis has 4 OFDM code elements in a time slot in Fig. 7 and Fig. 8.But,, also can use above method in the same manner even change the number of OFDM code element.In this case, the pilot that can be positioned at the OFDM code element of time slot edge is set to R_Side according to the sub-carrier power ratio, and the pilot that can be positioned at all the other OFDM code elements of time slot central authorities is set to R_Center according to the sub-carrier power ratio.

Now, another exemplary embodiment of the present invention will be described below briefly.In this exemplary embodiment of describing with reference to figure 5 to Fig. 8, suppose that an OFDM BCMCS time slot has the CDM time slot that at least one is adjacent.But, when the OFDM time slot has a CDM time slot that is adjacent, can be only be set to R_Side according to the sub-carrier power ratio for the pilot of the OFDM code element that is arranged in the OFDM time slot that is close to the CDM time slot.

Fig. 9 is the figure that diagram is used for transmitting continuously the exemplary time slot format of OFDM BCMCS time

slot.Reference numeral

412 and 413 expressions are used to transmit the OFDM BCMCS time slot of identical broadcasts information, and receiver receives OFDM BCMCS time slot 412 and 413.But the BCMCS receiver does not receive CDM time slot 411 and 414.In this case, in the channel estimation process of demodulating ofdm code element 124, the BCMCS receiver can use the OFDM code element of OFDM BCMCS time slot 413.In exemplary embodiment of the present invention,, should distribute power according to the sub-carrier power ratio to them according to different pilot though

OFDM code element

121 and 124 all is positioned at time slot edge.

In order to solve possible in this case problem, exemplary embodiment of the present invention provides the position that is used to separate OFDM code element in the time slot and the method for different pilot according to the expansion of sub-carrier power ratio has been set.

Show the form of the signaling message that is used to indicate power ratio at table 4.

Table 4

Field	Length (bit)
		[...]	[...]
PilotToneToDataTonePowerRatioIncluded	1
		[...]	[...]
Interlace0Included	1
		FirstSymbolsPTDTPR0	0 or N
SecondSymbolsPTDTPR0	0 or N
		ThirdSymbolsPTDTPR0	0 or N
FourthSymbolsPTDTPR0	0 or N
		[...]	[...]
Interlace1Included	1
		FirstSymbolsPTDTPR1	0 or N
SecondSymbolsPTDTPR1	0 or N
		ThirdSymbolsPTDTPR1	0 or N
FourthSymbolsPTDTPR1	0 or N
		[...]	[...]
Interlace2Included	1
		FirstSymbolsPTDTPR2	0 or N
SecondSymbolsPTDTPR2	0 or N
		ThirdSymbolsPTDTPR2	0 or N
FourthSymbolsPTDTPR2	0 or N
		[...]	[...]
Interlace3Included	1
		FirstSymbolsPTDTPR3	0 or N
SecondSymbolsPTDTPR3	0 or N
		ThirdSymbolsPTDTPR3	0 or N
FourthSymbolsPTDTPR3	0 or N
		[...]	[...]

Table 4 shows the field that only is used for embodiments of the invention, and omitted the field that other is used to support the BCMCS service.To specifically describe each field of the signaling message shown in the table 4 now below.

" PilotToneToDataTonePowerRatioIncluded " field has indicated whether to comprise the value of pilot sub-carrier to data sub-carrier power ratio.If this field value is set to " 0 ", then expression does not comprise pilot sub-carrier to data sub-carrier power ratio, and has used the default value of initial setting up.But if this field value is set to " 1 ", then expression has comprised in the pilot of all using between OFDM code element transmission period according to the sub-carrier power ratio.

" InterlaceXIncluded " field has indicated whether to comprise will use " X " time slot that interweaves and the information that transmits.Here, X representes 0,1,2 or 3.If this field value is set to " 0 ", then expression does not comprise transmission information, and if this field value is set to " 1 ", then expression comprises transmission information.

" FirstSymbolsPTDTPRX (pilot sub-carrier of first code element that in the X time slot that interweaves, transmits is to the ratio of data sub-carrier power; X=0,1,2 or 3 wherein) " field comprises the value of the pilot of first code element (for example, the OFDM code element 121 of Fig. 9) that is used for being transmitted in the time slot corresponding among the OFDM code element that transmits on the time slot according to the sub-carrier power ratio.Only be set to " 1 " and " InterlaceXIncluded " field when being set to " 1 " when " PilotToneToDataTonePowerRatioIncluded " field, just comprise " FirstSymbolsPTDTPRX " field.

" SecondSymbolsPTDTPRX (pilot sub-carrier of second code element that in the X time slot that interweaves, transmits is to the ratio of data sub-carrier power; X=0,1,2 or 3 wherein) " field comprises the value of the pilot of second code element (for example, the OFDM code element 122 of Fig. 9) that is used for being transmitted in the time slot corresponding among the OFDM code element that transmits on the time slot according to the sub-carrier power ratio.Only be set to just comprise when " 1 " and " InterlaceXIncluded " field is set to " 1 " " SecondSymbolsPTDTPRX " field when " PilotToneToDataTonePowerRatioIncluded " field.

" ThirdSymbolsPTDTPRX (pilot sub-carrier of the 3rd code element that in the X time slot that interweaves, transmits is to the ratio of data sub-carrier power; X=0,1,2 or 3 wherein) " field comprises the value of the pilot of the 3rd code element (for example, the OFDM code element 123 of Fig. 9) that is used for being transmitted in the time slot corresponding among the OFDM code element that transmits on the time slot according to the sub-carrier power ratio.Only be set to " 1 " and " InterlaceXIncluded " field when being set to " 1 " when " PilotToneToDataTonePowerRatioIncluded " field, just comprise " ThirdSymbolsPTDTPRX " field.

" FourthSymbolsPTDTPRX (pilot sub-carrier of the 4th code element that in the X time slot that interweaves, transmits is to the ratio of data sub-carrier power; X=0,1,2 or 3 wherein) " field comprises the value of the pilot of the 4th code element (for example, the OFDM code element 124 of Fig. 9) that is used for being transmitted in the time slot corresponding among the OFDM code element that transmits on the time slot according to the sub-carrier power ratio.Only be set to just comprise when " 1 " and " InterlaceXIncluded " field is set to " 1 " " FourthSymbolsPTDTPRX " field when " PilotToneToDataTonePowerRatioIncluded " field.

Figure 10 is diagram according to another exemplary embodiment of the present invention, at the flow chart of the operation of the conveyer of the HRPD system that is used for broadcast service; In this embodiment, conveyer is for the independent position of OFDM code element and use different pilot according to the sub-carrier power ratio.In exemplary embodiment of the present invention, be called the base station at the conveyer of the HRPD system that is used for broadcast service.

In step 10, conveyer uses channel encoder 301, channel interleaver 302 and modulator 303, generates data subcarrier according to the broadcast data that will transmit.In step 11, conveyer will protect subcarrier to be inserted in the data subcarrier, and, in step 12, pilot sub-carrier is inserted in the data subcarrier that inserts the protection subcarrier.

In step 13, conveyer confirms whether corresponding OFDM code element is positioned at the primary importance of time slot.If the OFDM code element is an OFDM code element of time slot, then in step 14, conveyer arrives pilot sub-carrier and data subcarrier according to power ratio R_1 with power division.Otherwise in step 15, conveyer confirms whether the OFDM code element is positioned at the second place of time slot.If the OFDM code element is the 2nd an OFDM code element of time slot, then in step 16, conveyer arrives pilot sub-carrier and data subcarrier according to power ratio R_2 with power division.Otherwise in step 17, conveyer confirms whether the OFDM code element is positioned at the 3rd position of time slot.If the OFDM code element is the 3rd an OFDM code element of time slot, then in step 18, conveyer arrives pilot sub-carrier and data subcarrier according to power ratio R_3 with power division.Otherwise, because its indication OFDM code element is positioned at the rearmost position of time slot, so in step 19, conveyer arrives pilot sub-carrier and data subcarrier according to power ratio R_4 with power division.

Afterwards, in step 20, conveyer is carried out different QPSK expansions according to BCMCS content designator, use QPSK expander 307.In step 21, conveyer uses IFFT unit 308 to carry out IFFT and handles, and, use CP inserter 309 that CP is inserted in the code element after IFFT handles, thereby accomplish ofdm signal.Afterwards, conveyer uses HRPD compatible processor 310 to carry out the HRPD compatible processing in step 22, and in step 23, transmits the ofdm signal of accomplishing.

With reference to Figure 11, recover the description of the processing of broadcast singal in the time of will making the ofdm signal that generates when the operation that receives through Figure 10 now at receiver.

Figure 11 is diagram according to another exemplary embodiment of the present invention, at the flow chart of the operation of the receiver of the HRPD system that is used for broadcast service; In this embodiment, receiver is for the independent position of OFDM code element and use different pilot according to the sub-carrier power ratio.In exemplary embodiment of the present invention, be called the terminal at the receiver of the HRPD system that is used for broadcast service.

In step 30, receiver from the base station or conveyer receive R_1, R_2, R_3 and R_4.When reception R_1, R_2, R_3 and R_4 failed, receiver used initial R_1, R_2, R_3 and R_4 value.When receiving the BCMCS time slot, receiver extracts the OFDM code element from the BCMCS time slot that is received in step 31, and in step 32, the OFDM code element of being extracted is carried out the QPSK despreading.

In step 33, receiver confirms whether the OFDM code element is positioned at the primary importance of time slot.If the OFDM code element is an OFDM code element of time slot, then in the step 34, receiver is being carried out channel estimating according to pilot according to sub-carrier power ratio R _ 1.Otherwise in step 35, receiver confirms whether the OFDM code element is positioned at the second place of time slot.If the OFDM code element is the 2nd an OFDM code element of time slot, then in step 36, receiver is carried out channel estimating according to pilot according to sub-carrier power ratio R _ 2.Otherwise in step 37, receiver confirms whether the OFDM code element is positioned at the 3rd position of time slot.If the OFDM code element is the 3rd an OFDM code element of time slot, then in step 38, receiver is carried out channel estimating according to pilot according to sub-carrier power ratio R _ 3.Otherwise, because its indication OFDM code element is positioned at the rearmost position of time slot, so in step 39, receiver is carried out channel estimating according to pilot according to sub-carrier power ratio R _ 4.In step 34,36,38 and 39 channel estimation process, receiver uses the pilot sub-carrier that is arranged in adjacent OFDM code element.

In step 40, receiver extracts data subcarrier from estimated channel, and the data subcarrier that extracts of demodulation.In step 41, receiver is the broadcast singal of demodulated data subcarrier decoding for transmitting from conveyer the most at last.

As stated, conveyer is provided with the different power ratio according to the position of the OFDM code element in the ofdm signal time slot that transmits.When receiving ofdm signal, receiver comes ofdm signal is carried out channel estimating according to the power ratio of correspondence, thereby improves the channel estimating performance of OFDM code element.

Figure 12 be diagram according to an embodiment of the invention, be used to be received in the block diagram of structure that position according to the OFDM code element is provided with the receiver of the ofdm signal that conveyer transmits after the different power ratio.With reference to Figure 12, will make according to an embodiment of the invention, be used to be received in structure and the description of operation that position according to the OFDM code element is provided with the receiver of the ofdm signal that conveyer transmits after the different power ratio now.

Receiver can with the HRPD technical compatibility.Therefore, the compatible receiving processor 71 of HRPD receives the HRPD signal, is mapped to the section data signal from the HRPD signal extraction that is received, and confirms that the data that received are OFDM data or CDM data.Under the situation of broadcast service, whether the compatible receiving processor 71 of HRPD can have the value " 1 " of indication broadcast service through inspection MSB, and the transmission plan of definite data that received.

As stated, in the HRPD system, receiver can be received in the broadcast singal that each time slot of OFDM is transmitted by conveyer, perhaps, is received in clean culture (unicast) signal or control signal that each time slot is transmitted through CDM by conveyer.At first, receive the control signal of CDM transmission so that detect the description of pilot with being made in receiver according to the method for sub-carrier power ratio.When receiving from the control signal of HRPD system or power ratio signal, the compatible receiving processor 71 of HRPD outputs to power ratio message receiver 72 with the signal that receives.Power ratio message receiver 72 extracts power ratio message from the CDM control signal, and will output to channel estimating weight decisions device 73 according to the power ratio value that the power ratio message of being extracted is selected.Here, term " power ratio " indication pilot is according to the sub-carrier power ratio.

Channel estimating weight decisions device 73 uses the power ratio value, confirms the weighting of needed each the independent channel of channel estimating, and the channel estimating weighting of confirming is outputed to channel estimator 78.

Next, with the description of the method that is made in the signal that OFDM that receiver receives transmits.The signal that OFDM is transmitted is input to OFDM processor 1200.Now, the data management that is described in the OFDM processor 1200 is handled.

OFDM processor 1200 is provided to CP remover 74 with the ofdm signal that is received, to remove the CP from the ofdm signal that is received.CP remover 74 is removed and is damaged the CP of (contaminate) owing to propagation delay with from the multidiameter of received signal, and the signal that will remove CP outputs to fast Fourier transform (FFT) processor 75.Fft processor 75 converts the time-domain signal of input into frequency-region signal, and this frequency-region signal is outputed to QPSK despreader 76.76 pairs of said frequency-region signals of QPSK despreader carry out the QPSK despreading, and the signal of QPSK despreading is outputed to pilot sub-carrier extractor 77.The reason that 76 pairs of said frequency-region signals of QPSK despreader carry out the QPSK despreading is: before transmission, conveyer has carried out the QPSK expansion to transmission signals.As shown in Figure 3, based on mixing, QPSK despreader 76 output protection subcarriers, pilot sub-carrier and data subcarrier.Pilot sub-carrier extractor 77 extracts pilot sub-carrier from the QPSK despread signal, the pilot sub-carrier that is extracted is outputed to channel estimator 78, and all the other subcarriers are outputed to data subcarrier extractor 79.Data subcarrier extractor 79 only is extracted in the subcarrier that is mapped to data among the subcarrier of pilot sub-carrier extractor 77 output, and the data subcarrier that is extracted is outputed to demodulator 80.

To be input to channel estimator 78 through the pilot sub-carrier that pilot sub-carrier extractor 77 extracts.Channel estimator 78 uses estimates channel by the 73 determined channel estimating weightings of channel estimating weight decisions device.

After channel estimating, channel estimator 78 outputs to demodulator 80 with the estimated channel value.Demodulator 80 uses estimated channel value to come the demodulating data subcarrier, and the signal of demodulation is outputed to deinterleaver 81.Deinterleaver 81 restituted signal that deinterleaves, and the signal that deinterleaves outputed to decoder 82.Decoder 82 decoding deinterleaves signal, thereby the signal that recovery is transmitted, the broadcast singal that is for example transmitted.

Figure 13 be diagram according to an embodiment of the invention, in the HRPD system, receive the flow chart of the processing of ofdm signal at receiver.With reference to Figure 13, will make now to according to an embodiment of the invention, on the receiver of HRPD system, receive the specific descriptions of the processing of ofdm signal.

With reference to Figure 13, in step 51, receiver received power ratio message.According to transmission method, receiver receives this power ratio message in a different manner.When receiving power ratio message, receiver uses power ratio message receiver 72, channel estimating weight decisions device 73 and channel estimator 78 to confirm the estimated channel value.In step 52, receiver reads the DCPilotToDataRatio field from the power ratio message that is received, and storage DC pilot is according to the sub-carrier power ratio.In this case, receiver is stored the power information of the pilot sub-carrier that is used to be positioned at the time slot outside of transmitting the OFDM code element and is used to be positioned at the inboard pilot sub-carrier of time slot and the power information of data subcarrier.Afterwards, in step 53, receiver confirms whether the MSB of the EBCMCSTransmissionFormat field in the message that is received is set to " 1 ", if this MSB is set to " 1 ", then receiver advances to step 54.Otherwise receiver advances to step 55.

In step 55, receiver confirms whether the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", if the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", then receiver advances to step 62.Otherwise receiver advances to step 61.In step 62; Do not consider the order of time slot and read ACPilotToDataRatioOuterSymbols field and ACPilotToDataRatioInnerSymbols field; And, store the AC pilot according to the sub-carrier power ratio in inner OFDM code element and outside OFDM code element.In step 61, receiver is not considered the order of time slot and the position in the time slot, and reads the ACPilotToDataRatio field, and storage AC pilot is according to the sub-carrier power ratio.

In step 54, receiver confirms whether the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", is set to " 1 " if confirm the value of DualPDREnabledForThisLogicalCh field, and then receiver advances to step 64.Otherwise receiver advances to step 63.

In step 64; Receiver reads ACPilotToDataRatioOuterSymbols1 field and the ACPilotToDataRatioInnerSymbols1 field that is used to change transformat time slot before; And, store the AC pilot according to the sub-carrier power ratio in inner OFDM code element and outside OFDM code element.In addition; Receiver is used to change the ACPilotToDataRatioOuterSymbols2 field and the ACPilotToDataRatioInnerSymbols2 field of transformat time slot afterwards; And, store the AC pilot according to the sub-carrier power ratio in inner OFDM code element and outside OFDM code element.

In step 63; Do not consider the position of OFDM code element in the time slot; And read ACPilotToDataRatio1 field and ACPilotToDataRatio2 field, and the time slot after the time slot before transformat changes and the transformat change is stored the AC pilot according to the sub-carrier power ratio respectively.

After

step

61,62,63 or 64, in step 65, the receiving symbol of receiver storage pilot sub-carrier.Afterwards, in step 66, confirm the channel estimating weighting according to sub-carrier power ratio and AC pilot according to the sub-carrier power ratio according to the DC pilot.In step 67, receiver uses the channel estimating weighting, through the receiving symbol of combination and insertion pilot sub-carrier, the channel that comes the data estimator subcarrier to be experienced.In step 68, receiver uses the estimated channel value, recovers broadcast singal through the data subcarrier is carried out the demodulation sign indicating number.

Like what understand according to foregoing description; Set different pilot according to the sub-carrier power ratio with the BCMCS transmission equipment based on OFDM of HRPD technical compatibility according to the position of OFDM code element, thereby improve the channel estimating performance of the OFDM code element that is positioned at time slot edge.The improvement of channel estimating performance is contributed the improvement of receptivity to some extent.

Though illustrated and combine some embodiment to describe the present invention, it will be apparent to one skilled in the art that and to make the various changes in form and the details therein and do not deviate from the spirit and scope of the present invention that in appended claim, define.For example, though to the system applies of the OFDM transmission plan of BCMCS technical support and HRPD technical compatibility wherein exemplary embodiment of the present invention, also can be to other broadcast system application implementation example based on OFDM.

Claims

1. one kind is transmitted the equipment of Orthodoxy Frequency Division Multiplex (OFDM) code element at the GSM that is used for broadcast service, and this equipment comprises:

Transmission processor is used for through coding, interweaves and modulate the code element that the physical layer packet that will transmit generates modulation, and in the data subcarrier of OFDM code element, arranges the code element of modulating;

The subcarrier inserter is used for protection subcarrier and pilot sub-carrier are inserted into the OFDM code element;

The sub-carrier power distributor is used for different pilot being set according to the sub-carrier power ratio according to the position of time slot OFDM code element, and distributes power according to pilot according to the sub-carrier power ratio;

And

Conveyer is used to transmit the OFDM code element.

2. equipment as claimed in claim 1; Wherein, If the OFDM code element is positioned at the outside of time slot, then the sub-carrier power distributor arrives pilot sub-carrier and data subcarrier according to the sub-carrier power ratio with power division according to first pilot, and; If the OFDM code element is positioned at the inboard of time slot, then the sub-carrier power distributor arrives pilot sub-carrier and data subcarrier according to the sub-carrier power ratio with power division according to second pilot.

3. equipment as claimed in claim 1, wherein, the sub-carrier power distributor is provided with different pilot according to the sub-carrier power ratio according to the position of OFDM code element in the time slot, and passes through signaling message and transmit pilot according to the sub-carrier power rate information.

4. equipment as claimed in claim 3, wherein, signaling message comprises about the information of direct current pilot according to the sub-carrier power ratio.

5. equipment as claimed in claim 3; Wherein, signaling message comprise indicate whether to comprise pilot according to the field of sub-carrier power rate information, comprise that the pilot that is used for being transmitted in the inside OFDM code element that said time slot transmits is according to the field of sub-carrier power rate information and comprise that the pilot that is used for being transmitted in the outside OFDM code element that said time slot transmits is according in the field of sub-carrier power rate information at least one.

6. equipment as claimed in claim 3, wherein, signaling message comprises: about between the transmission period of OFDM code element, use different pilot according to the pilot of the sub-carrier power ratio information according to the sub-carrier power ratio for each interweaves separately.

7. equipment as claimed in claim 3; Wherein, signaling message comprises: indicate whether to comprise pilot according to the field of sub-carrier power rate information, indicate whether to comprise the field of the information that will use each time slot that interweaves and transmit separately, the pilot of transmission that comprises the inside OFDM code element that is used in each interweaves the said time slot that comprises, transmitting separately according to the field of sub-carrier power rate information and the pilot of transmission that comprises the outside OFDM code element that is used in each interweaves the said time slot that comprises, transmitting separately according in the field of sub-carrier power rate information at least one.

8. equipment as claimed in claim 1, wherein, the sub-carrier power distributor between the transmission period of OFDM code element, for each interweave separately provide different pilot according to the sub-carrier power ratio.

9. one kind is transmitted the method for Orthodoxy Frequency Division Multiplex (OFDM) code element at the GSM that is used for broadcast service, and this method may further comprise the steps:

Through coding, interweave and modulate the code element that the physical layer packet that will transmit generates modulation, and in the data subcarrier of OFDM code element, arrange the code element of modulating;

To protect subcarrier and pilot sub-carrier to be inserted in the OFDM code element;

Position according to OFDM code element in the time slot is provided with different pilot according to the sub-carrier power ratio, and distributes power according to pilot according to the sub-carrier power ratio; And

Transmit the OFDM code element.

10. method as claimed in claim 9; Wherein, The sub-carrier power allocation step is further comprising the steps of: if the OFDM code element is positioned at the outside of time slot, then according to the sub-carrier power ratio power division is arrived pilot sub-carrier and data subcarrier according to first pilot, and; If the OFDM code element is positioned at the inboard of time slot, then according to the sub-carrier power ratio power division is arrived pilot sub-carrier and data subcarrier according to second pilot.

11. method as claimed in claim 9 is further comprising the steps of: the position according to OFDM code element in the time slot is provided with different pilot according to the sub-carrier power ratio, and passes through signaling message and transmit pilot according to the sub-carrier power rate information.

12. method as claimed in claim 11, wherein, signaling message comprises about the information of direct current pilot according to the sub-carrier power ratio.

13. method as claimed in claim 11; Wherein, signaling message comprise indicate whether to comprise pilot according to the field of sub-carrier power rate information, comprise that the pilot that is used for being transmitted in the inside OFDM code element that said time slot transmits is according to the field of sub-carrier power rate information and comprise that the pilot that is used for being transmitted in the outside OFDM code element that said time slot transmits is according in the field of sub-carrier power rate information at least one.

14. method as claimed in claim 11, wherein, signaling message comprises: about between the transmission period of OFDM code element, use different pilot according to the pilot of the sub-carrier power ratio information according to the sub-carrier power ratio for each interweaves separately.

15. method as claimed in claim 11; Wherein, signaling message comprises: indicate whether to comprise pilot according to the field of sub-carrier power rate information, indicate whether to comprise the field of the information that will use each time slot that interweaves and transmit separately, the pilot of transmission that comprises the inside OFDM code element that is used in each interweaves the said time slot that comprises, transmitting separately according to the field of sub-carrier power rate information and the pilot of transmission that comprises the outside OFDM code element that is used in each interweaves the said time slot that comprises, transmitting separately according in the field of sub-carrier power rate information at least one.

16. method as claimed in claim 9, wherein, between the transmission period of OFDM code element, for each interweave separately provide different pilot according to the sub-carrier power ratio.

17. the method in the GSM receiving orthogonal frequency division that is used for broadcast service multiplexing (OFDM) code element, this method may further comprise the steps:

Receiving about according to the position of OFDM code element and definite pilot during according to the information of sub-carrier power ratio, the storage pilot is according to the sub-carrier power ratio;

Receive the OFDM code element, remove Cyclic Prefix, convert the time-domain signal of importing into frequency-region signal, and extract data subcarrier and pilot sub-carrier;

Use the pilot sub-carrier and the pilot of OFDM code element to estimate channel according to the sub-carrier power ratio; And

Use channel estimating demodulates information data subcarrier, the signal of institute's demodulation is deinterleaved, and the signal that deinterleaves of decoding, thereby restore data.

18. method as claimed in claim 17; Wherein, Channel estimation steps may further comprise the steps: if the OFDM code element is positioned at the outside of time slot, then according to first pilot according to sub-carrier power Ratio Estimation channel, and; If the OFDM code element is positioned at the inboard of time slot, then according to second pilot according to sub-carrier power Ratio Estimation channel.

19. the equipment in the GSM receiving orthogonal frequency division that is used for broadcast service multiplexing (OFDM) code element, this equipment comprises:

Receiving element is used for receiving control message, from control messages, extracts pilot according to the position of OFDM code element according to the sub-carrier power ratio;

The OFDM processor is used for the OFDM code element is handled, and it comprises:

The Cyclic Prefix remover is used to remove Cyclic Prefix;

Fft processor is used for converting the time-domain signal of input into frequency-region signal;

The pilot sub-carrier extractor is used to extract pilot sub-carrier, and pilot sub-carrier is provided to channel estimating unit; With

The data subcarrier extractor is used to extract data subcarrier, and the dateout subcarrier;

Channel estimating unit is used to use pilot sub-carrier and pilot according to sub-carrier power Ratio Estimation channel; And

Data recovery unit, it comprises:

Demodulator is used to use the channel estimation value that provides from channel estimating unit and the demodulating data subcarrier;

Deinterleaver is used for the signal of institute's demodulation is deinterleaved; With

Decoder, the signal that is used to decode and deinterleaves.

20. equipment as claimed in claim 19, wherein, channel estimating unit comprises:

Channel estimating weight decisions device is used for confirming the channel estimating weighting according to the output of receiving element;

And

Channel estimator is used for receive channel and estimates the weighted sum pilot sub-carrier, and the value of confirming channel estimating according to the position and the power of pilot sub-carrier.