CN102868658B

CN102868658B - The equipment of transmission/reception packet data symbol and method in mobile communication system

Info

Publication number: CN102868658B
Application number: CN201210278185.3A
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: 2016-03-23
Anticipated expiration: 2025-12-03
Also published as: RU2007120632A; RU2349032C1; BRPI0517319B1; CN102868658A; BRPI0517319A; JP4510093B2; CN101057422B; KR20060063632A; CN101057422A; JP2008522540A

Abstract

Disclose the equipment and method that transmit Orthodoxy Frequency Division Multiplex (OFDM) code element in mobile communication system.Transmission processor by coding, interweave and modulate the physical layer packet that will transmit and generate the code element of modulation, and in the data subcarrier of OFDM symbol, arrange the code element of modulation.Pilot sub-carrier is inserted in OFDM symbol by tone inserter.Tone power allocator arranges different pilot according to tone power ratio according to the position of OFDM symbol in time slot, and distributes power according to pilot according to tone power ratio.Conveyer transmits OFDM symbol.

Description

The equipment of transmission/reception packet data symbol and method in mobile communication system

The application is international filing date is on December 03rd, 2005, application number is PCT/KR2005/004109(China application number is 200580039018.1), denomination of invention is the divisional application of the application for a patent for invention of " equipment and method for transmission/reception packet data symbol in mobile communication system "

Technical field

The present invention relates generally to equipment and method for providing broadcast service in radio packet communication system.Particularly, the present invention relates to and in the broadcast system using Orthodoxy Frequency Division Multiplex (OFDM) transmission plan, control to the power division of pilot sub-carrier (pilottone) equipment and method for controlling.

Background technology

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

Usually, radio packet communication system is supported in the specific user of transmission and the specific communication service receiving exchange message between user.In this communication service, different reception users is by different channel receiving informations.But the channel lower due to it and the isolation of channel and the interchannel interference caused, radio packet communication system suffers penalty.In order to increase the isolation of channel and channel, current mobile communication system uses the multiple access (rdma) scheme of cellular concept and such as Code Division Multiple Access (CDMA), time-division multiple access (TDMA) (TDMA), frequency division multiple access (FDMA) and so on.But, even if use these technology, interference can not be removed completely.

Different from communication service, BCMCS service allows to transmit user's uniaxially and information is sent to multiple reception user.Because they share identical channel, so, not interference between the user receiving identical information.But, because the multipath occurred in the environment of high-speed mobile (multipath) decline, so mobile broadcast service suffers penalty.In order to solve (address) this problem, the broadcast system being designed to the mobile reception supporting such as digital video broadcast terrestrial (DVB-T), DVB-H and digital audio broadcasting (DAB) system and so on uses OFDM transfer scheme.

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

The down link of HRPD (high rate packet data) (HRPD) mobile communication system 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 of time slot (slot) form of the down link be illustrated in traditional HRPD mobile communication system.

As is illustrated in figure 1, a time slot has the form repeated with half time slot.N will be had _pilotthe pilot tone 103 and 108 of leaf length is inserted in the central authorities of half time slot, and described pilot tone 103 and 108 is for the channel estimating of the down link at receiving terminal.Transmit at the two ends of pilot tone 103 and 108 comprise uplink power control information and resource allocation information, there is N _mACthe media interviews of leaf length control (MAC) information 102,104,107 and 109.Transmitted before and after MAC information 102,104,107 and 109 and there is N _datathe actual transmissions data 101,105,106 and 110 of leaf length.In this way, by TDM, time division multiplexing is carried out to pilot tone, MAC information, real data.

By CDM, utilize walsh codes and carry out multiplexed to MAC and data message, and, in 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.

Fig. 2 is that diagram is by being inserted into the figure of the time slot format provided in the data transfer interval for the HRPD downlink time slots of BCMCS service by OFDM symbol.

Compatible for HRPD down link, the position of pilot tone and MAC signal and the position of size and pilot tone shown in Figure 1 and MAC signal and size match shown in figure 2.Namely, N will be had _pilotthe pilot tone 103 and 108 of leaf length is placed in the central authorities of half time slot, and will have N _mACthe MAC signal 102,104,107 and 109 of leaf length is placed in the both sides of pilot signal 103 and 108.Therefore, even if do not support that the existing HRPD terminal based on the broadcast service of OFDM is also estimated channel by pilot tone and receives MAC signal.OFDM symbol 121,122,123 and 124 is inserted in all the other fields (that is, data transfer interval 101,105,106 and 110) of time slot.OFDM symbol 121,122,123 and 124 is provided by modulation BCMCS information.

At N _datain the existing HRPD downlink system of=400, the size of OFDM symbol is set to N _data=400.Cyclic Prefix (CP) is arranged in the head of each OFDM symbol by OFDM scheme, to prevent from being caused self-interference due to multipath fading by the Received signal strength of time delay.Namely, an OFDM symbol comprises CP125 and the OFDM data 126 by generating BCMCS information and executing inverse fast fourier transform (IFFT).The size of CP125 is N _cPsheet, and, for CP125, copy N at OFDM data 126 afterbody _cPsheet signal, is then arranged in the head of OFDM data 126.Therefore, the size of OFDM data 126 becomes (N _data-N _cP) sheet.At this, according to the allowed time delay causing self-interference, determine N _cP.N _cPincrease add the number of just demodulated delayed reception signal, and not disturb, but, due to the minimizing of OFDM data size, decrease transmissible amount of information.But, N _cPminimizing add transmissible amount of information, but, due to the high interference possibility in serious multipath fading environments, reduce the quality of reception.

In SFN, because receive the identical signal transmitted by several terminal in terminal at different time, so, usually the size of CP is set to higher value.In the HRPD downlink system transmitting the ofdm signal being used for BCMCS service, preferably, by N _cPbe set to 80 (N _cP=80).In this case, the size of OFDM data becomes 320.This expression can perform IFFT to 320 modulated symbols, and in OFDM data transmission intercal, transmit the code element after IFFT process.Therefore, by OFDM scheme, 320 subcarriers (tone) altogether can be obtained.

But, be not that whole 320 subcarriers can be used for transmission of data symbols.Some subcarriers being positioned at used band edge should be used as: for the protection subcarrier preventing out of band signal from becoming interference.Because before transmission, the pilot tone 103 and 108 that uses different codes to expand (spread) to use in existing HRPD down link on different conveyer, so they are not suitable for the channel estimating of the BCMCS service provided in SFN.Therefore, the dedicated pilot of the channel estimating for ofdm signal is additionally needed.A part for subcarrier can be used to be transmitted in predefined signal between conveyer and receiver, then this predefined signal is used for channel estimating, and, such subcarrier is called OFDM dedicated pilot subcarrier.The OFDM scheme used in SFN allows the time delay relatively grown, thus causes serious frequency-selecting decline (frequency-selectivefading).Therefore, even if need can ensure that pilot sub-carrier is enough to perform channel estimating when serious frequency-selecting declines, also.

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

With reference to figure 3, protection subcarrier 201 is arranged in the edge of frequency band.By the low frequency part of 8 protection subcarrier permutation in 16 protection subcarriers at frequency band, and by the HFS of all the other 8 protection subcarrier permutation at frequency band.Obstructed overprotection subcarrier transmission signal, so, power is not provided to protection subcarrier.Data subcarrier 203 is arranged in the central authorities of frequency band.Finally, because pilot sub-carrier 202 is for channel estimating, so, arrange pilot sub-carrier 202 with the regular interval of every 5 subcarriers.Arrangement of subcarrier in this way, that is, followed by the pilot sub-carrier be arranged in low-limit frequency after four protection subcarriers, and then insert pilot sub-carrier.

Similarly, even if also insert pilot sub-carrier 202 in the field being arranged data subcarrier 203, then, followed by pilot sub-carrier 202 after four data subcarriers 203, further, after new pilot sub-carrier 202 is arranged in these four data subcarriers 203.In this way, pilot sub-carrier 202 is arranged in the frequency corresponding to direct current (DC) component.Because pilot sub-carrier 202 is DC subcarriers, so, do not distribute power to them before transmission or distribute low-power to them.

Pilot sub-carrier 202 and data subcarrier 203 are mutually different in the power be assigned with.The preferred plan of ratio of the power being assigned to pilot sub-carrier 202 to the power being assigned to data subcarrier 203 should by conveyer and receiver predefine, this is because described ratio is different according to channel condition.

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

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

The Physical layer packet data generated in the upper layer is input to channel encoder 301.This Packet Data Channel is encoded to the bit stream of chnnel coding by channel encoder 301, and the bit stream of this chnnel coding is outputted to channel interleaver 302.The bit stream of intertexture, to obtain diversity gain, and is outputted to modulator 303 by the interweave bit stream (or performing column permutation (columnpermutation) to it) of this chnnel coding of channel interleaver 302.The bit stream of intertexture is modulated to modulation signal by modulator 303.This modulation signal is arranged in data subcarrier 203.

The signal exported from modulator 303 is arranged in the protection subcarrier 201 being arranged in band edge by protection tone inserter 304; further, pilot sub-carrier 202 is arranged in from the signal protecting tone inserter 304 to export with regular interval by pilot sub-carrier inserter 305.Afterwards, tone power allocator 306 to the ratio R of power being assigned to data subcarrier, distributes power according to the power being assigned to pilot sub-carrier.In QPSK expander 307, after being assigned to whole subcarrier, QPSK expansion is carried out to signal transmission.In QPSK extension process, the base station signal being used for transmitting different BCMCS contents is multiplied by different multiple pseudo noise (PN) sequences.Multiple PN sequence represents that real component and imaginary component all comprise the complex sequences of PN code.

Because on the receiver, undesired base station signal may become noise component(s), so receiver can perform to channel the channel estimating be separated with undesirable base station.According to input BCMCS content identifier and be created on the multiple PN sequence used in QPSK extension process.

The modulation signal expanded at the positional alignment QPSK of the frequency sub-carrier of hope by IFFT process in IFFT unit 308.Afterwards, CP inserter 309 inserts CP in the signal exported from IFFT unit 308, to prevent the self-interference caused due to multipath fading, thus completes the generation of OFDM transmission signal.Afterwards, HRPD compatible processor 310 continues to perform HRPD transmission process, to insert pilot tone 103 and 108 and MAC information 102,104,107 and 109.The signal of final transmission has time slot format shown in figure 2.

By reference to Fig. 5 A and Fig. 5 B, now the description of the form transmitting OFDMBCMCS time slot between CDM time slot will be made in.Fig. 5 A is the figure being illustrated in the form transmitting OFDMBCMCS time slot between CDM time slot.Here, this CDM time slot has time slot format shown in Figure 1, and, comprise the multiplexed signal of CDM at its data field.OFDMBCMCS time slot has time slot format shown in figure 2.

By reference to Fig. 5 A, the description of channel estimation process will made each OFDM symbol in the terminal receiving the OFDMBCMCS time slot 402 transmitted between CDM time slot 401 and 403 now.

OFDMBCMCS time slot 402 comprises 4 OFDM symbol 121,122,123 and 124 wherein.Reference numeral 121 and 124 instruction is positioned at the OFDM symbol of time slot edge, and Reference numeral 122 and 123 instruction is positioned at the OFDM symbol of time slot central authorities.

Usually, because the length of OFDM symbol is defined as make channel can not be changed in OFDM symbol, so the channel-changing between adjacent OFDM symbol is not remarkable.Therefore, the OFDM symbol being positioned at time slot central authorities can use the pilot sub-carrier of edge OFDM symbol, to estimate channel.Such as, the pilot sub-carrier of the not only pilot sub-carrier of OFDM symbol 122, and OFDM symbol 121 and 123 is used to the channel of estimating OFDM code element 122, thus improves channel estimating performance.

But in channel estimation process, the OFDM symbol being arranged in time slot edge has limitation using the pilot sub-carrier of adjacent OFDM symbol.More specifically, the pilot sub-carrier for the channel of estimating OFDM code element 121 comprises the pilot sub-carrier of OFDM symbol 121 and the pilot sub-carrier of OFDM symbol 122.This is because: owing to transferring CDM time slot instead of BCMCS time slot before the transmission of OFDM symbol 121, so do not have pilot sub-carrier to be used to Signal estimation.Therefore, the OFDM symbol 122 and 123 being positioned at OFDMBCMCS time slot central authorities is better than the OFDM symbol 121 and 124 being positioned at OFDMBCMCS time slot edge in channel estimating performance.This is because, do not consider the position of OFDM symbol, identical value for the power that is assigned to independent pilot sub-carrier to the ratio R of power of power being assigned to independent data subcarrier.

As a result, compared with being positioned at the OFDM symbol of OFDMBCMCS time slot central authorities, the OFDM symbol being positioned at time slot edge has the higher reception mistake possibility during occurring in transfer of data.

As illustrated in figure 5b, even if when OFDMBCMCS time slot transmits continuously, this phenomenon also can occur.Reference numeral 405,406 all represents with 407 the OFDMBCMCS time slot transmitting different broadcast message.The terminal receiving the broadcast message of OFDMBCMCS time slot 406 does not need to receive OFDMBCMCS time slot 405 and 407.Therefore, even if when transmitting OFDMBCMCS time slot continuously, receiving wrong possibility still can be not identical according to the position of OFDM symbol.

Summary of the invention

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

Another object of the present invention is, is provided for the equipment and the method that regulate and distribute the power of pilot sub-carrier in based on the HRPD mobile communication system of OFDM transmission scheme according to the position of OFDM symbol.

According to an exemplary aspect of the present invention, provide the equipment transmitting packet data symbol in for HRPD (high rate packet data) (HRPD) mobile communication system of broadcast service.This equipment comprises transmission processor, for the physical layer packet that will be transmitted by coding, intertexture and modulation, and generates the code element of modulation, and in data subcarrier, arranges the code element of modulation; Tone inserter, for being inserted in data subcarrier by protection subcarrier and pilot sub-carrier; Tone power allocator, arranges different pilot according to tone power ratio, and distributes power according to pilot according to tone power ratio for the position according to time slot, wherein, comprise packet data symbol at described time slot; And conveyer, for transmitting packet data symbol.

According to an exemplary aspect of the present invention, provide the equipment transmitting Orthodoxy Frequency Division Multiplex (OFDM) code element in mobile communication system.This equipment comprises: transmission processor, generates the code element of modulation, and in the data subcarrier of OFDM symbol, arrange the code element of modulation for the physical layer packet that will be transmitted by coding, intertexture and modulation; Tone inserter, for being inserted in OFDM symbol by pilot sub-carrier; Tone power allocator, arranges different pilot according to tone power ratio for the position according to OFDM symbol in time slot, and distributes power according to pilot according to tone power ratio; And conveyer, for transmitting OFDM symbol.

According to another exemplary aspect of the present invention, provide the method transmitting packet data symbol in for HRPD (high rate packet data) (HRPD) mobile communication system of broadcast service.The method comprises the following steps: by coding, interweave and modulate the physical layer packet that will transmit, and generating the code element of modulation, and in data subcarrier, arranging the code element of modulation; Protection subcarrier and pilot sub-carrier are inserted in data subcarrier; According to the position of time slot, different pilot is set according to tone power ratio, and distributes power according to pilot according to tone power ratio, wherein, comprise packet data symbol at described time slot; And transmission packet data symbol.

According to another exemplary aspect of the present invention, provide the method transmitting Orthodoxy Frequency Division Multiplex (OFDM) code element in mobile communication system.The method comprises the following steps: by coding, interweave and modulate the physical layer packet that will transmit and generate the code element of modulation, and in the data subcarrier of OFDM symbol, arranging the code element of modulation; Pilot sub-carrier is inserted in OFDM symbol; According to the position of OFDM symbol in time slot, different pilot is set according to tone power ratio, and distributes power according to pilot according to tone power ratio; And transmission OFDM symbol.

According to another exemplary aspect of the present invention, provide the method for receiving packet data symbol in for HRPD (high rate packet data) (HRPD) mobile communication system of broadcast service.The method comprises the following steps: receiving about according to when transmitting information according to tone power ratio of the position of packet data symbol and the pilot determined, stores according to the pilot of element position according to tone power ratio; If the grouping received is Orthodoxy Frequency Division Multiplex (OFDM) grouping, then divide into groups to extract data symbols from this OFDM, and the data symbols that despreading (despread) is extracted, thus extract data subcarrier and pilot sub-carrier; Use the pilot of OFDM grouping according to tone power ratio, estimate channel; And use channel-estimation information, recover data from data subcarrier.

According to another exemplary aspect of the present invention, provide the method for receiving orthogonal frequency division in mobile communication system multiplexing (OFDM) code element.The method comprises the following steps: when receiving information according to tone power ratio of the pilot determined about the position according to OFDM symbol, store pilot according to tone power ratio; Receive OFDM symbol, remove Cyclic Prefix, the time-domain signal of input is converted to frequency-region signal, and extracts data subcarrier and pilot sub-carrier; The pilot sub-carrier of OFDM symbol and pilot is used to estimate channel according to tone power ratio; And use channel-estimation information demodulating data subcarrier, the signal of institute's demodulation is deinterleaved, and the signal deinterleaved of decoding, thus recover data.

According to another exemplary aspect of the present invention, provide the equipment of receiving packet data symbol in for HRPD (high rate packet data) (HRPD) mobile communication system of broadcast service.This equipment comprises: channel estimating unit, for receiving control message, to extract according to the pilot of the position of packet data symbol according to tone power ratio, determines channel estimation weight, and estimate channel according to pilot according to tone power ratio; Orthodoxy Frequency Division Multiplex (OFDM) processor, for received OFDM symbol is divided into pilot sub-carrier and data subcarrier, is provided to channel estimating unit by pilot sub-carrier, and exports data subcarrier; And data recovery unit, for using the channel-estimation information provided from channel estimating unit, recover the information transmitted from data subcarrier.

According to another exemplary aspect of the present invention, provide the equipment of receiving orthogonal frequency division in mobile communication system multiplexing (OFDM) code element.This equipment comprises: receiving element, for receiving control message, extracts according to the pilot of the position of OFDM symbol according to tone power ratio from control message; OFDM processor, for processing OFDM symbol, it comprises: Cyclic Prefix remover, for removing Cyclic Prefix; Fft processor, for being converted to frequency-region signal by the time-domain signal of input; Pilot sub-carrier extractor, for extracting pilot sub-carrier, and is provided to channel estimating unit by pilot sub-carrier; With data subcarrier extractor, for extracting data subcarrier, and export data subcarrier; Channel estimating unit, estimates channel for using pilot sub-carrier and pilot according to tone power ratio; And data recovery unit, it comprises: demodulator, for using the channel estimation value and demodulating data subcarrier that provide from channel estimating unit; Deinterleaver, for deinterleaving to the signal of institute's demodulation; And decoder, the signal deinterleaved for decoding.

Accompanying drawing explanation

When read in conjunction with the accompanying drawings from the description of lower mask body, above and other exemplary purpose of the present invention, feature and advantage will become clearer, in the accompanying drawings, will understand, and identical Reference numeral represents identical part, element and structure, wherein:

Fig. 1 is the figure of the time slot format of the down link be illustrated in traditional HRPD mobile communication system;

Fig. 2 is that diagram is by being inserted into the figure of the time slot format provided for the data transfer interval of the HRPD downlink time slots of BCMCS service by OFDM symbol;

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

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

Fig. 5 A is the figure being illustrated in the form transmitting OFDMBCMCS time slot between CDM time slot;

Fig. 5 B is the figure being illustrated in the form transmitting OFDMBCMCS time slot between OFDMBCMCS time slot;

Fig. 6 be diagram according to exemplary embodiment of the present invention, in for the HRPD system of broadcast service the block diagram of the structure of conveyer;

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

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

Fig. 9 is the figure being illustrated in the example slot form transmitting OFDMBCMCS time slot between CDM time slot continuously;

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

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

Figure 12 be diagram according to an embodiment of the invention, for the position received according to OFDM symbol, different power ratios is set after the block diagram of the structure of the receiver of ofdm signal that transmits of conveyer; And

Figure 13 A and Figure 13 B is the flow chart receiver of diagram according to an embodiment of the invention, in HRPD system receiving the process of ofdm signal.

Embodiment

Now, several exemplary embodiment of the present invention is specifically described with reference to accompanying drawing.In the accompanying drawings, as already pointed out, even if describe them in different drawings, also identical or close element is represented by identical Reference numeral.In the following description, for clarity and conciseness, the specific descriptions of known function and the configuration merged at this have been eliminated.

With the system of the OFDM transmission scheme of HRPD compatibility, BCMCS time slot may not can be transmitted continuously in use.Therefore, channel estimating performance depends on whether OFDM symbol is positioned at time slot edge or time slot central authorities.The OFDM symbol being positioned at time slot edge in channel estimating performance inferior to the OFDM symbol being positioned at time slot central authorities.Namely, because do not consider the position of OFDM symbol, identical value for the power that is assigned to independent pilot sub-carrier to the ratio R of power of power being assigned to independent data subcarrier, so the wrong possibility being positioned at the OFDM symbol of time slot edge increases.

Therefore, exemplary embodiment of the present invention provides the method regulating and distributing the power of pilot sub-carrier according to the position of time slot, thus improves receiving ability.

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

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

Fig. 6 be diagram according to exemplary embodiment of the present invention, in for the HRPD system of broadcast service the block diagram of the structure of conveyer.

Conveyer comprise channel encoder 301 for carrying out chnnel coding to received grouped data, for the grouped data of coding is interweaved channel interleaver 302, for modulate the grouped data of intertexture modulator 303, for protection subcarrier being inserted into the protection tone inserter 304 signal exported from modulator 303, and for pilot sub-carrier being inserted the pilot sub-carrier inserter 305 of the signal exported from protection tone inserter 304.In addition, conveyer comprises tone power allocator 606, QPSK expander 307, IFFT unit 308, CP inserter 309, and HRPD compatible processor 310.

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

The Physical layer packet data generated in the upper layer is input to channel encoder 301.This Packet Data Channel is encoded to the bit stream of chnnel coding by channel encoder 301, and the bit stream of this chnnel coding is outputted to channel interleaver 302.Channel interleaver 302 interweaves the bit stream (or to its perform rank transformation) of this chnnel coding, to realize diversity gain, and the bit stream of intertexture is outputted to modulator 303.The bit stream of intertexture is modulated to modulation signal by modulator 303.This modulation signal is arranged in data subcarrier 203.

The signal exported from modulator 303 is arranged in the protection subcarrier 201 being arranged in band edge by protection tone inserter 304; further, pilot sub-carrier 202 is arranged in from the signal protecting tone inserter 304 to export with regular interval by pilot sub-carrier inserter 305.

Afterwards, tone power allocator 606, according to the element position (namely, whether corresponding OFDM symbol is positioned at time slot edge or time slot central authorities) of correspondence, regulates and distributes the power of pilot sub-carrier.This more specifically describes with reference to Fig. 5 A.For the OFDM symbol 121 and 124 being positioned at time slot edge, power ratio R_Side is used to carry out point power being used in pilot sub-carrier and data subcarrier.For the OFDM symbol 122 and 123 being positioned at time slot central authorities, power ratio R_Center is used to distribute the power of pilot sub-carrier and data subcarrier.As mentioned above, in exemplary realization, predefine R_Side and R_Center value.

In QPSK expander 307, after being assigned to whole subcarrier, QPSK expansion is carried out to signal transmission.IFFT unit 308 arranges the modulation signal of QPSK expansion in the position of the frequency sub-carrier of hope by IFFT process.Afterwards, CP inserter 309 inserts CP in the signal exported from IFFT unit 308, thus completes the generation of OFDM transmission signal.

Exemplary embodiment of the present invention arranges variable pilot according to tone power ratio (that is, variable pilot sub-carrier power is to the ratio of data tone power) according to the position of OFDM symbol.But alternatively, the ad-hoc location that also can be OFDM symbol arranges fixing power ratio.According to exemplary embodiment of the present invention, because OFDM symbol may be transmitted at whole time slot, so HRPD system uses variable power ratio and revocable power ratio.

In order to use variable power ratio and revocable power ratio, the information of the power ratio about the position based on OFDM symbol is sent to the signaling message that is used for supporting BCMCS to serve in HRPD system (such as by base station, air broadcast (BroadcastOverhead) message) terminal, with to the current pilot of terminal notification according to tone power ratio.

In order to arrange pilot changeably according to tone power ratio, following two exemplary embodiments can be considered.

In first embodiment, base station provides to terminal has the information of instruction pilot according to tone power ratio, and the time slot usually transmitting OFDM symbol wherein provides this pilot according to tone power ratio.Show the form of the signaling message of the terminal of the general power ratio of notice in first embodiment that base station uses in Table 1.

Table 1

Table 1 illustrate only the field used in an exemplary embodiment of the present invention, and eliminates other field for supporting BCMCS to serve.The signaling message illustrated in Table 1 is configured to the pilot of the code element of instruction two type according to tone power ratio.Suppose to transmit 4 OFDM symbol on 1 time slot, so, HRPD system can indicate pilot for each OFDM symbol according to tone power ratio.But, because two code elements being positioned at time slot central authorities be positioned at time slot edge two code elements property class seemingly, so pilot is indicated as the load that can reduce signaling message according to tone power ratio.Each field of the signaling message shown in table 1 will be described in below.

" DualPDREnabled " field indicates whether the ratio (double pilot to data tone power ratio (two PDR(DualPDR)) of the pilot sub-carrier power of the code element employing two types to data tone power).If be set to " 1 " by this field value, then its expression employs two PDR.But, if this field value is set to " 0 ", then represent that the pilot only employed for the code element of a type is according to tone power ratio.

" EBCMCSTransmissionFormat " field instruction transformat.If the highest significant position of this field (MSB) is set to " 0 ", then represents and employ the transformat not supporting variable format.But, if the MSB of this field is set to " 1 ", then represent the transformat employing and support variable format.When transmitting multiple time slot, variable format allows each independent time slot to transmit OFDM symbol with other form.According to exemplary embodiment of the present invention, be the number of the size of CP, the number of pilot sub-carrier and protection subcarrier by the formal definition being used for the OFDM symbol of variable format.Namely, when supporting variable format, may be each independent time slot transmission OFDM symbol, wherein, being applied to described OFDM symbol by all having the CP of different size (or length), pilot sub-carrier and protection subcarrier.Therefore, the suitable PDR value of independent time slot may be different.When reason supports variable format for this reason, need before or after change of format, arrange different PDR values.

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

Whether the logic channel of " DualPDREnabledForThisLogicalChannel " field instruction correspondence comprises two PDR.If be set to " 1 " by this field value, then corresponding logic channel uses two PDR, and it indicates the field that will be defined by this field about two PDR.But, if be set to " 0 " by this field value, then represent that corresponding logic channel does not use two PDR.

" ACPilotToDataGainRecord " field instruction AC pilot sub-carrier power is to the ratio (that is, AC pilot is according to tone power ratio) of data tone power.If " DualPDREnabledForThisLogicalChannel " field is set to " 0 ", then instruction does not use two PDR, represents " ACPilotToDataGainRecord " field with the form shown in table 2A or 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 not using variable format according to tone power ratio, and shows 2B and show AC pilot for the situation using variable format according to tone power ratio.

Table 2A shows when " DualPDREnabledForThisLogicalChannel " field is set to " 0 " and MSB in " EBCMCSTransmissionFormat " field is set to " 0 ", when namely not using two PDR and variable format, how to represent " ACPilotToDataGainRecord " field." ACPilotToDataGain " field instruction AC pilot according to tone power ratio, and is not considered the position of corresponding code element and is identical value by " ACPilotToDataGain " Field Definition.

Table 2B shows when " DualPDREnabledForThisLogicalChannel " field is set to " 0 " and MSB in " EBCMCSTransmissionFormat " field is set to " 1 ", when namely not using two PDR and employ variable format, how to represent " ACPilotToDataGainRecord " field." ACPilotToDataGain1 " field instruction transformat change before AC pilot according to tone power ratio, and " ACPilotToDataGain2 " field instruction AC pilot after transformat changes, according to tone power ratio, and is not considered the position of corresponding code element and is identical value by " ACPilotToDataGain2 " Field Definition.

If " DualPDREnabledForThisLogicalChannel " field is set to " 1 ", thus instruction uses two PDR, then represent " ACPilotToDataGainRecord " field with the form shown in table 2C or 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 not using variable format according to tone power ratio, and shows 2D and show AC pilot for the situation using variable format according to tone power ratio.

Table 2C shows when " DualPDREnabledForThisLogicalChannel " field is set to " 1 " and MSB in " EBCMCSTransmissionFormat " field is set to " 0 ", when namely using two PDR and do not use variable format, how to represent " ACPilotToDataGainRecord " field." ACInternalPilotToDataGain " field comprises the value of pilot according to tone power ratio for transmitting the central code element in the OFDM symbol that transmits over a slot, and " ACBoundaryPilotToDataGain " field comprises the value of pilot according to tone power ratio for transmitting the edge code element in the OFDM symbol that transmits over a slot.

Table 2D shows when " DualPDREnabledForThisLogicalChannel " field is set to " 1 " and MSB in " EBCMCSTransmissionFormat " field is set to " 1 ", when namely using two PDR and variable format, how to represent " ACPilotToDataGainRecord " field." ACInternalPilotToDataGain1 " field and " ACBoundaryPilotToDataGain1 " field comprise the pilot for transmitting the central code element in the OFDM symbol that transmits over a slot respectively according to the value of tone power ratio and the value of pilot according to tone power ratio for transmitting the edge code element in the OFDM symbol that transmits over a slot, and are used before transformat changes.

" ACInternalPilotToDataGain2 " field and " ACBoundaryPilotToDataGain2 " field comprise the pilot for transmitting the central code element in the OFDM symbol that transmits over a slot respectively according to the value of tone power ratio and the value of pilot according to tone power ratio for transmitting the edge code element in the OFDM symbol that transmits over a slot, and are used after transformat changes.

In second exemplary embodiment, base station provides to terminal has the information of instruction pilot according to tone power ratio, wherein, applies described pilot according to tone power ratio at the time slot transmitting OFDM symbol for each independent intertexture.Only one or multiple intertexture can be used for OFDM symbol transmission with the HRPD system of 4 time slot interleaving transmission plan operations.Therefore, between OFDM symbol transmission period, HRPD system can arrange different pilot according to tone power ratio for each independent intertexture.

Show the form of the signaling message that base station in the second embodiment uses in table 3, its in order to terminal notification between OFDM symbol transmission period for the variable pilot of each independent intertexture according to tone power ratio.

Table 3

Table 3 illustrate only for the field at embodiments of the invention, and eliminates other field for supporting BCMCS to serve.The signaling message illustrated in table 3 is configured to comprise instruction and is used for the pilot of the code element of two types according to tone power ratio.

Signaling message can comprise be used to indicate each code element pilot according to the field of tone power ratio.But as shown in table 3, signaling message comprises the field of pilot according to tone power ratio of the code element being used to indicate two types, to reduce the load of signaling message.

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

" PilotToneToDataTonePowerRatioIncluded " field indicates whether to include the value of pilot sub-carrier to data tone power ratio.If this field value is set to " 0 ", then represents and do not comprise pilot sub-carrier to data tone power ratio, and use default value.But, if be set to " 1 " by this field value, then represent that the pilot sub-carrier including and use between the transmission period of whole OFDM symbol is to data tone power ratio.

The information that " InterlaceXIncluded " field indicates whether to include " X " that will use intertexture and transmits.Here, X represents 0,1,2 or 3.If this field value is set to " 0 ", then represents and do not comprise transmission information, and if this field value is set to " 1 ", then represent comprise transmission information.

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

The instruction of " the pilot sub-carrier power of the limit code element that SideSymbolsPTDTPRX(transmits in intertexture X time slot to the ratio of data tone power, wherein X=0,1,2 or 3) " field is for transmitting the pilot of the code element (sidesymbols) on the limit of the time slot comprised at InterlaceX transmitting in OFDM symbol according to tone power ratio value.Only when " PilotToneToDataTonePowerRatioIncluded " field is set to " 1 " and " InterlaceXIncluded " field is set to " 1 ", just comprise " SideSymbolsPTDTPRX " field.

N shown in table 1 to table 3 is used to indicate the value of pilot according to tone power ratio.Can represent this value or can encode to it before transmission by dB, and its resolution can be depending on the size of N.

With reference to figure 7, by make according to exemplary embodiment of the present invention, be that transmission time slot sets different pilot according to tone power ratio value, the specific descriptions making can use the operation of the conveyer of the value of constant power ratio on the position of specific OFDM symbol always for the position according to OFDM symbol.

Fig. 7 is diagram according to exemplary embodiment of the present invention, flow chart in the operation for the conveyer in the HRPD system of broadcast service.In an exemplary embodiment of the present invention, base station is being called for the conveyer in the HRPD system of 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 a step 702, protection subcarrier is inserted in data subcarrier, and, in step 703, pilot sub-carrier is inserted in the data subcarrier having inserted protection subcarrier.In step 704, conveyer determines that corresponding OFDM symbol is positioned at the central authorities of time slot or the edge of time slot.If determine that OFDM symbol is positioned at time slot edge, then in step 705, conveyer according to power ratio R_Side by power division to pilot sub-carrier and data subcarrier.But, if determine that OFDM symbol is positioned at time slot central authorities, then in step 706, conveyer according to power ratio R_Center by power division to pilot sub-carrier and data subcarrier.

Afterwards, in step 707, conveyer uses QPSK expander 307, performs different QPSK expansions according to BCMCS content designator.In step 708, conveyer uses IFFT unit 308 to perform IFFT process, and in code element after using CP inserter 309 CP to be inserted IFFT process, thus complete ofdm signal.Afterwards, conveyer uses HRPD compatible processor 310 to perform HRPD compatible processing in step 709, and the ofdm signal transmitted in step 720.

With reference to figure 8, will make when receiving the ofdm signal generated by the operation of Fig. 7, recover the description of the exemplary process of broadcast singal at receiver now.

Fig. 8 is diagram according to exemplary embodiment of the present invention, flow chart in the operation for the receiver in the HRPD system of broadcast service.In an exemplary embodiment of the present invention, terminal is being called for the receiver in the HRPD system of 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 BCMCS time slot, receiver extracts OFDM symbol from received BCMCS time slot in step 802, and performs QPSK despreading to extracted OFDM symbol in step 803.

Afterwards, in step 804, receiver performs channel estimating, and determines whether OFDM symbol is positioned at time slot edge.If the OFDM symbol received is positioned at time slot edge, then receiver proceeds to step 805, and wherein, it performs channel estimating according to pilot according to tone power ratio R_Side.

But if determine that OFDM symbol is positioned at time slot central authorities, then receiver proceeds to step 806, wherein, it performs channel estimating according to pilot according to tone power ratio R_Center.Step 805 and 806 channel estimation process in, receiver uses and is positioned at the pilot sub-carrier of adjacent OFDM symbol.In step 807, receiver extracts data subcarrier from estimated channel, and the data subcarrier that demodulation is extracted.In step 808, the data subcarrier of receiver demodulation is the most at last decoded as the broadcast singal transmitted from conveyer.

Suppose there are 4 OFDM symbol in one time slot in figures 7 and 8.But, even if change the number of OFDM symbol, also above method can be applied in the same manner.In this case, the pilot of the OFDM symbol being positioned at time slot edge can be set to R_Side according to tone power ratio, and the pilot of all the other OFDM symbol being positioned at time slot central authorities can be set to R_Center according to tone power ratio.

Now, below another exemplary embodiment of the present invention will be described briefly.In this exemplary embodiment described with reference to figure 5 to Fig. 8, suppose the CDM time slot that an OFDMBCMCS time slot has at least one and is adjacent.But, when OFDM time slot have one be adjacent CDM time slot time, only can will be set to R_Side for the pilot of the OFDM symbol being arranged in the OFDM time slot being close to CDM time slot according to tone power ratio.

Fig. 9 is that diagram is for transmitting the figure of the example slot form of OFDMBCMCS time slot continuously.Reference numeral 412 and 413 represents the OFDMBCMCS time slot for transmitting identical broadcasts information, and receiver receives OFDMBCMCS time slot 412 and 413.But 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, BCMCS receiver can use the OFDM symbol of OFDMBCMCS time slot 413.In an exemplary embodiment of the present invention, although OFDM symbol 121 and 124 is all positioned at time slot edge, power should be distributed according to tone power ratio to them according to different pilot.

In order to solve in this case possible problem, exemplary embodiment of the present invention provides for the position for OFDM symbol independent in time slot and arranges the method for different pilot according to the expansion of tone power ratio.

The form of the signaling message being used to indicate power ratio is shown 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 only for the field of embodiments of the invention, and eliminates other field for supporting BCMCS to serve.To specifically describe each field of the signaling message shown in table 4 below now.

" PilotToneToDataTonePowerRatioIncluded " field indicates whether to include the value of pilot sub-carrier to data tone power ratio.If this field value is set to " 0 ", then represents and do not comprise pilot sub-carrier to data tone power ratio, and employ the default value of initial setting up.But, if be set to " 1 " by this field value, then represent that the pilot including and use between whole OFDM symbol transmission period is according to tone power ratio.

" InterlaceXIncluded " field indicates whether to include and will use " X " time slot of intertexture and the information transmitted.Here, X represents 0,1,2 or 3.If this field value is set to " 0 ", then represents and do not comprise transmission information, and if this field value is set to " 1 ", then represent comprise transmission information.

" pilot sub-carrier of the first code element that FirstSymbolsPTDTPRX(transmits in intertexture X time slot is to the ratio of data tone power; wherein X=0,1,2 or 3) " field comprises the value of pilot according to tone power ratio of the first code element (such as, the OFDM symbol 121 of Fig. 9) in the time slot for transmitting the correspondence among the OFDM symbol that transmits over a slot.Only when " PilotToneToDataTonePowerRatioIncluded " field is set to " 1 " and " InterlaceXIncluded " field is set to " 1 ", just comprise " FirstSymbolsPTDTPRX " field.

" pilot sub-carrier of the second code element that SecondSymbolsPTDTPRX(transmits in intertexture X time slot is to the ratio of data tone power; wherein X=0,1,2 or 3) " field comprises the value of pilot according to tone power ratio of the second code element (such as, the OFDM symbol 122 of Fig. 9) in the time slot for transmitting the correspondence among the OFDM symbol that transmits over a slot.Only just comprise " SecondSymbolsPTDTPRX " field when " PilotToneToDataTonePowerRatioIncluded " field is set to " 1 " and " InterlaceXIncluded " field is set to " 1 ".

" pilot sub-carrier of the third yard unit that ThirdSymbolsPTDTPRX(transmits in intertexture X time slot is to the ratio of data tone power; wherein X=0,1,2 or 3) " field comprises the value of pilot according to tone power ratio of the third yard unit (such as, the OFDM symbol 123 of Fig. 9) in the time slot for transmitting the correspondence among the OFDM symbol that transmits over a slot.Only when " PilotToneToDataTonePowerRatioIncluded " field is set to " 1 " and " InterlaceXIncluded " field is set to " 1 ", just comprise " ThirdSymbolsPTDTPRX " field.

" pilot sub-carrier of the 4th code element that FourthSymbolsPTDTPRX(transmits in intertexture X time slot is to the ratio of data tone power; wherein X=0,1,2 or 3) " field comprises the value of pilot according to tone power ratio of the 4th code element (such as, the OFDM symbol 124 of Fig. 9) in the time slot for transmitting the correspondence among the OFDM symbol that transmits over a slot.Only just comprise " FourthSymbolsPTDTPRX " field when " PilotToneToDataTonePowerRatioIncluded " field is set to " 1 " and " InterlaceXIncluded " field is set to " 1 ".

Figure 10 is diagram according to another exemplary embodiment of the present invention, flow chart in the operation for the conveyer in the HRPD system of broadcast service, in this embodiment, conveyer for OFDM symbol independent position and use different pilot according to tone power ratio.In an exemplary embodiment of the present invention, base station is being called for the conveyer in the HRPD system of 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 a step 11, protection subcarrier is inserted in data subcarrier by conveyer, and, in step 12, pilot sub-carrier is inserted in the data subcarrier having inserted protection subcarrier.

In step 13, conveyer determines whether corresponding OFDM symbol is positioned at the primary importance of time slot.If OFDM symbol is the first OFDM symbol of time slot, then at step 14, conveyer according to power ratio R_1 by power division to pilot sub-carrier and data subcarrier.Otherwise in step 15, whether conveyer determination OFDM symbol is positioned at the second place of time slot.If OFDM symbol is the second OFDM symbol of time slot, then in step 16, conveyer according to power ratio R_2 by power division to pilot sub-carrier and data subcarrier.Otherwise in step 17, whether conveyer determination OFDM symbol is positioned at the 3rd position of time slot.If OFDM symbol is the 3rd OFDM symbol of time slot, then in step 18, conveyer according to power ratio R_3 by power division to pilot sub-carrier and data subcarrier.Otherwise, because its instruction OFDM symbol is positioned at the rearmost position of time slot, so, in step 19, conveyer according to power ratio R_4 by power division to pilot sub-carrier and data subcarrier.

Afterwards, in step 20, conveyer performs different QPSK expansions according to BCMCS content designator, use QPSK expander 307.In step 21, conveyer uses IFFT unit 308 to perform IFFT process, and, in the code element after using CP inserter 309 CP to be inserted into IFFT process, thus complete ofdm signal.Afterwards, conveyer uses HRPD compatible processor 310 to perform HRPD compatible processing in step 22, and the ofdm signal transmitted in step 23.

With reference to Figure 11, now the description recovering the process of broadcast singal when receiving the ofdm signal generated by the operation of Figure 10 at receiver will be made.

Figure 11 is diagram according to another exemplary embodiment of the present invention, flow chart in the operation for the receiver in the HRPD system of broadcast service, in this embodiment, receiver for OFDM symbol independent position and use different pilot according to tone power ratio.In an exemplary embodiment of the present invention, terminal is being called for the receiver in the HRPD system of broadcast service.

In step 30, receiver receives R_1, R_2, R_3 and R_4 from base station or conveyer.When receiving R_1, R_2, R_3 and R_4 failure, receiver uses initial R_1, R_2, R_3 and R_4 value.When receiving BCMCS time slot, receiver extracts OFDM symbol from received BCMCS time slot in step 31, and performs QPSK despreading to extracted OFDM symbol in the step 32.

In step 33, whether receiver determination OFDM symbol is positioned at the primary importance of time slot.If OFDM symbol is the first OFDM symbol of time slot, then in step 34, receiver is performing channel estimating according to pilot according to tone power ratio R_1.Otherwise in step 35, whether receiver determination OFDM symbol is positioned at the second place of time slot.If OFDM symbol is the second OFDM symbol of time slot, then in step 36, receiver performs channel estimating according to pilot according to tone power ratio R_2.Otherwise in step 37, whether receiver determination OFDM symbol is positioned at the 3rd position of time slot.If OFDM symbol is the 3rd OFDM symbol of time slot, then in step 38, receiver performs channel estimating according to pilot according to tone power ratio R_3.Otherwise, because its instruction OFDM symbol is positioned at the rearmost position of time slot, so in step 39, receiver performs channel estimating according to pilot according to tone power ratio R_4.Step 34,36, in the channel estimation process of 38 and 39, receiver uses the pilot sub-carrier being arranged in adjacent OFDM symbol.

In step 40, receiver extracts data subcarrier from estimated channel, and the data subcarrier that demodulation is extracted.In step 41, the data subcarrier of receiver demodulation is the most at last decoded as the broadcast singal transmitted from conveyer.

As mentioned above, conveyer arranges different power ratios according to the position of the OFDM symbol in the ofdm signal time slot transmitted.When receiving ofdm signal, receiver comes to perform channel estimating to ofdm signal according to the power ratio of correspondence, thus improves the channel estimating performance of OFDM symbol.

Figure 12 be diagram according to an embodiment of the invention, for the position be received according to OFDM symbol, different power ratios is set after the block diagram of the structure of the receiver of ofdm signal that transmits of conveyer.With reference to Figure 12, will make according to an embodiment of the invention, be used for the position be received according to OFDM symbol now and the structure of receiver of the ofdm signal that conveyer transmits and the description of operation after different power ratios is set.

Receiver can with HRPD technical compatibility.Therefore, HRPD compatible receiver processor 71 receives HRPD signal, is mapped to the part signal of data from received HRPD signal extraction, and determines that received data are OFDM data or CDM data.When broadcast service, HRPD compatible receiver processor 71 by checking whether MSB has the value " 1 " of instruction broadcast service, and determines the transmission plan of received data.

As mentioned above, in HRPD system, receiver can be received in the broadcast singal that each time slot of OFDM is transmitted by conveyer, or, be received in clean culture (unicast) signal or control signal that each time slot transmitted by CDM by conveyer.First, the control signal of CDM transmission is received to detect the description of pilot according to the method for tone power ratio by being made in receiver.When receiving from the control signal of HRPD system or power ratio signal, the signal received is outputted to power ratio message receiver 72 by HRPD compatible receiver processor 71.Power ratio message receiver 72 extracts power ratio message from CDM control signal, and the power ratio value selected according to extracted power ratio message is outputted to channel estimation weight decision device 73.Here, term " power ratio " indicates pilot according to tone power ratio.

Channel estimation weight decision device 73 uses power ratio value, determines the weighting of each independent channel required for channel estimating, and the channel estimation weight determined is outputted to channel estimator 78.

Next, the description of the method for the signal of the OFDM transmission that receiver receives will be made in.The signal that OFDM transmits is input to OFDM processor 1200.Now, the data management process in OFDM processor 1200 will be described in.

Received ofdm signal is provided to CP remover 74 by OFDM processor 1200, to remove the CP from received ofdm signal.CP remover 74 remove due to propagation delay and from received signal multidiameter and damage the CP of (contaminate), and the signal eliminating CP is outputted to fast Fourier transform (FFT) processor 75.The time-domain signal of input is converted to frequency-region signal by fft processor 75, and this frequency-region signal is outputted to QPSK despreader 76.QPSK despreader 76 carries out QPSK despreading to described frequency-region signal, and the signal of QPSK despreading is outputted to pilot sub-carrier extractor 77.QPSK despreader 76 to the reason that described frequency-region signal carries out QPSK despreading is: before transmission, and conveyer has carried out QPSK expansion to signal transmission.As shown in Figure 3, based on mixing, QPSK despreader 76 output protection subcarrier, pilot sub-carrier and data subcarrier.Pilot sub-carrier extractor 77 extracts pilot sub-carrier from QPSK despread signal, extracted pilot sub-carrier is outputted to channel estimator 78, and its remaining sub-carriers is outputted to data subcarrier extractor 79.Data subcarrier extractor 79 is only extracted in from the subcarrier being mapped to data among the subcarrier of pilot sub-carrier extractor 77 output, and extracted data subcarrier is outputted to demodulator 80.

The pilot sub-carrier extracted by pilot sub-carrier extractor 77 is input to channel estimator 78.Channel estimator 78 uses by the determined channel estimation weight of channel estimation weight decision device 73 to estimate channel.

After the channel estimation, the channel value of estimation is outputted to demodulator 80 by channel estimator 78.Demodulator 80 uses estimated channel value to carry out demodulating data subcarrier, and the signal of demodulation is outputted to deinterleaver 81.Deinterleaver 81 deinterleaves restituted signal, and the signal deinterleaved is outputted to decoder 82.Decoder 82 is decoded deinterleaves signal, thus recovers the signal that transmits, such as transmitted broadcast singal.

Figure 13 A and Figure 13 B be diagram according to an embodiment of the invention, in HRPD system, receive the flow chart of process of ofdm signal at receiver.With reference to figure 13A and Figure 13 B, now by make to according to an embodiment of the invention, on the receiver of HRPD system, receive the specific descriptions of the process of ofdm signal.

With reference to figure 13A and Figure 13 B, 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 estimation weight decision device 73 and channel estimator 78 to determine the channel value estimated.In step 52, receiver reads DCPilotToDataRatio field from received power ratio message, and stores DC pilot according to tone power ratio.In this case, receiver stores for being positioned at the power information of the pilot sub-carrier outside the time slot transmitting OFDM symbol and the power information for being positioned at pilot sub-carrier inside time slot and data subcarrier.Afterwards, in step 53, whether the MSB of the EBCMCSTransmissionFormat field that receiver is determined in the received message is set to " 1 ", if this MSB is set to " 1 ", then receiver proceeds to step 54.Otherwise receiver proceeds to step 55.

In step 55, receiver determines whether the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", if the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", then receiver proceeds to step 62.Otherwise receiver proceeds to step 61.In step 62, do not consider the order of time slot and read ACPilotToDataRatioOuterSymbols field and ACPilotToDataRatioInnerSymbols field, further, AC pilot is stored according to tone power ratio in inner OFDM symbol and outside OFDM symbol.In a step 61, the position in the order of time slot and time slot do not considered by receiver, and reads ACPilotToDataRatio field, and stores AC pilot according to tone power ratio.

In step 54, receiver determines whether the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", if determine that the value of DualPDREnabledForThisLogicalCh field is set to " 1 ", then receiver proceeds to step 64.Otherwise receiver proceeds to step 63.

In step 64, receiver reads ACPilotToDataRatioOuterSymbols1 field for the time slot before changing transformat and ACPilotToDataRatioInnerSymbols1 field, further, AC pilot is stored according to tone power ratio in inner OFDM symbol and outside OFDM symbol.In addition, receiver is for the ACPilotToDataRatioOuterSymbols2 field of the time slot after changing transformat and ACPilotToDataRatioInnerSymbols2 field, further, AC pilot is stored according to tone power ratio in inner OFDM symbol and outside OFDM symbol.

In step 63, do not consider the position of OFDM symbol in time slot, and read ACPilotToDataRatio1 field and ACPilotToDataRatio2 field, and the time slot respectively before transformat changes and the time slot after transformat change store AC pilot according to tone power ratio.

After step 61,62,63 or 64, in step 65, receiver stores the receiving symbol of pilot sub-carrier.Afterwards, in the step 66, channel estimation weight is determined according to tone power ratio and AC pilot according to tone power ratio according to DC pilot.In step 67, receiver uses channel estimation weight, by combining and inserting the receiving symbol of pilot sub-carrier, carrys out the channel that data estimator subcarrier experiences.In the step 68, receiver uses the channel value estimated, recovers broadcast singal by performing demodulation code to data subcarrier.

As according to foregoing description understood, set different pilot according to tone power ratio from the BCMCS transmission equipment based on OFDM of HRPD technical compatibility according to the position of OFDM symbol, thus improve the channel estimating performance being positioned at the OFDM symbol of time slot edge.The improvement of improvement to receptivity of channel estimating performance is contributed to some extent.

Although illustrated and described the present invention in conjunction with some embodiment, it will be apparent to one skilled in the art that the various change that can make in form and details wherein and do not deviated from the spirit and scope of the present invention defined in the appended claims.Such as, although apply exemplary embodiment of the present invention to the system of the wherein OFDM transmission scheme of BCMCS technical support and HRPD technical compatibility, also can to other broadcast system Application Example based on OFDM.

Claims

1. transmit an equipment for Orthodoxy Frequency Division Multiplex (OFDM) code element in mobile communication system, this equipment comprises:

Transmission processor, is generated the code element of modulation, and in the data subcarrier of OFDM symbol, arranges the code element of modulation for the physical layer packet that will be transmitted by coding, intertexture and modulation;

Tone inserter, for being inserted in OFDM symbol by pilot sub-carrier;

Tone power allocator, arranges different pilot according to tone power ratio for the position according to OFDM symbol in time slot, and distributes power according to pilot according to tone power ratio; And

Conveyer, for transmitting OFDM symbol.

2. equipment as claimed in claim 1, wherein, if OFDM symbol is positioned at the outside of time slot, then tone power allocator according to the first pilot according to tone power ratio by power division to pilot sub-carrier and data subcarrier, and, if OFDM symbol is positioned at the inner side of time slot, then tone power allocator according to the second pilot according to tone power ratio by power division to pilot sub-carrier and data subcarrier.

3. equipment as claimed in claim 1, wherein, tone power allocator arranges different pilot according to tone power ratio according to the position of OFDM symbol in time slot, and passes through signaling message and transmit pilot according to tone power ratio information.

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

5. equipment as claimed in claim 3, wherein, signaling message comprise indicate whether to comprise pilot according to tone power ratio information field, comprise the pilot for transmitting the inside OFDM symbol transmitted in described time slot according to the field of tone power ratio information and comprise the pilot for transmitting the outside OFDM symbol transmitted in described time slot according at least one in the field of tone power ratio information.

6. equipment as claimed in claim 3, wherein, signaling message comprises: about between the transmission period of OFDM symbol, for the different pilot of each independent application that interweaves according to the pilot of tone power ratio according to the information of tone power ratio.

7. equipment as claimed in claim 3, wherein, signaling message comprises: indicate whether to comprise the field of pilot according to tone power ratio information, indicate whether separately to comprise and will use the time slot of each intertexture and the field of the information transmitted, comprise the field of pilot according to tone power ratio information of the transmission of the inside OFDM symbol transmitted in the described time slot for comprising in each intertexture separately, and the pilot of the transmission of the outside OFDM symbol transmitted in the described time slot comprising for comprising in each intertexture is separately according at least one in the field of tone power ratio information.

8. equipment as claimed in claim 1, wherein, tone power allocator between the transmission period of OFDM symbol, for each independent intertexture provides different pilot according to tone power ratio.

9. transmit a method for Orthodoxy Frequency Division Multiplex (OFDM) code element in mobile communication system, the method comprises the following steps:

By coding, interweave and modulate the physical layer packet that will transmit and generate the code element of modulation, and in the data subcarrier of OFDM symbol, arranging the code element of modulation;

Pilot sub-carrier is inserted in OFDM symbol;

According to the position of OFDM symbol in time slot, different pilot is set according to tone power ratio, and distributes power according to pilot according to tone power ratio; And

Transmit OFDM symbol.

10. method as claimed in claim 9, wherein, sub-carrier power allocation step is further comprising the steps of: if OFDM symbol is positioned at the outside of time slot, then according to the first pilot according to tone power ratio by power division to pilot sub-carrier and data subcarrier, and, if OFDM symbol is positioned at the inner side of time slot, then according to the second pilot according to tone power ratio by power division to pilot sub-carrier and data subcarrier.

11. methods as claimed in claim 9, further comprising the steps of: according to the position of OFDM symbol in time slot, different pilot to be set according to tone power ratio, and to pass through signaling message and transmit pilot according to tone power ratio information.

12. methods as claimed in claim 11, wherein, signaling message comprises about the information of direct current pilot according to tone power ratio.

13. methods as claimed in claim 11, wherein, signaling message comprise indicate whether to comprise pilot according to tone power ratio information field, comprise the pilot for transmitting the inside OFDM symbol transmitted in described time slot according to the field of tone power ratio information and comprise the pilot for transmitting the outside OFDM symbol transmitted in described time slot according at least one in the field of tone power ratio information.

14. methods as claimed in claim 11, wherein, signaling message comprises: about between the transmission period of OFDM symbol, for each independent pilot of the different pilot of application according to tone power ratio that interweave is according to the information of tone power ratio.

15. methods as claimed in claim 11, wherein, signaling message comprises: indicate whether to comprise the field of pilot according to tone power ratio information, indicate whether separately to comprise and will use the time slot of each intertexture and the field of the information transmitted, comprise the field of pilot according to tone power ratio information of the transmission of the inside OFDM symbol transmitted in the described time slot for comprising in each intertexture separately, and the pilot of the transmission of the outside OFDM symbol transmitted in the described time slot comprising for comprising in each intertexture is separately according at least one in the field of tone power ratio information.

16. methods as claimed in claim 9, wherein, between the transmission period of OFDM symbol, for each independent intertexture provides different pilot according to tone power ratio.

The method of 17. 1 kinds of receiving orthogonal frequency division multiplexing (OFDM) code elements in mobile communication system, the method comprises the following steps:

When receiving information according to tone power ratio of the pilot determined about the position according to OFDM symbol, store pilot according to tone power ratio;

Receive OFDM symbol, remove Cyclic Prefix, the time-domain signal of input is converted to frequency-region signal, and extracts data subcarrier and pilot sub-carrier;

The pilot of pilot sub-carrier and OFDM symbol is used to estimate channel according to tone power ratio; And

Use channel-estimation information demodulating data subcarrier, the signal of institute's demodulation is deinterleaved, and the signal deinterleaved of decoding, thus recover data.

18. methods as claimed in claim 17, wherein, channel estimation steps comprises the following steps: if OFDM symbol is positioned at the outside of time slot, then estimate channel according to the first pilot according to tone power ratio, and, if OFDM symbol is positioned at the inner side of time slot, then estimate channel according to the second pilot according to tone power ratio.

The equipment of 19. 1 kinds of receiving orthogonal frequency division multiplexing (OFDM) code elements in mobile communication system, this equipment comprises:

Receiving element, for receiving control message, extracts according to the pilot of the position of OFDM symbol according to tone power ratio from control message;

OFDM processor, for processing OFDM symbol, it comprises:

Cyclic Prefix remover, for removing Cyclic Prefix;

Fft processor, for being converted to frequency-region signal by the time-domain signal of input;

Pilot sub-carrier extractor, for extracting pilot sub-carrier, and is provided to channel estimating unit by pilot sub-carrier; With

Data subcarrier extractor, for extracting data subcarrier, and exports data subcarrier;

Channel estimating unit, estimates channel for using pilot sub-carrier and pilot according to tone power ratio; And

Data recovery unit, it comprises:

Demodulator, for using the channel-estimation information and demodulating data subcarrier that provide from channel estimating unit;

Deinterleaver, for deinterleaving to the signal of institute's demodulation; With

Decoder, the signal deinterleaved for decoding.

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

Channel estimation weight decision device, determines channel estimation weight for the output according to receiving element; And

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