CN101425874A - Data detection and demodulation for wireless communication systems - Google Patents

Abstract

A technology for detecting and demodulating data transmission in a wireless communication system is provided. On one hand, a decision-directed detector uses received data code elements and received pilot frequency code elements to perform detection of data transmission in received signals. The decision-directed detector is designed to be capable of performing differential detection in a frequency domain or coherent detection in a time domain, and can be used for multicarrier modulation (such as OFDM). On the other hand, an adaptive threshold is used to perform detection of received data transmission. Thresholds are respectively determined for each supposed received data transmission. For example, the thresholds can be calculated according to the energy of signals and noises of supposed data transmission.

Description

Be used for the Data Detection and the demodulation of radio communications system

The application is that the PCT international application no is PCT/US2003/034568, international filing date on October 24th, 2003, China national application number 200380102068.0, is entitled as the dividing an application of application of " being used for the Data Detection and the demodulation of radio communications system ".

Require priority according to the 35th of U.S.C § 119

It is the rights and interests of 60/421,309 U.S. Provisional Application that the application requires sequence number, and this application was applied on October 25th, 2002, " MIMO wlan system " by name, the assignee who transfers the application, its whole content is included in this as a reference for all purposes.

It is 60/432 that the application requires sequence number, the rights and interests of 626 U.S. Provisional Application, this application was applied on December 10th, 2002, " being used for the Data Detection and the demodulation of radio communications system " by name, transfer the application's assignee, its whole content is included in this as a reference for all purposes.

Background

I. field

Present invention relates in general to data communication, relate more specifically to be used for detect and the technology of demodulating data transmission at radio communications system.

II. background

In radio communications system, the data that are about to be transmitted processed usually (as, coding and modulation) upconvert to the RF modulation signal that is more suitable on wireless channel, transmitting with generation on radio frequency (RF) carrier signal then.The RF modulation signal is launched from transmitter then, and arrives receivers via a plurality of propagation paths in the wireless channel.Since multiple factor, for example decay, multipath and external disturbance, and the characteristic of propagation path changes along with the time usually.Therefore, the RF modulation signal may experience different channel conditions (as, different decay and multipath effect), and may be relevant with the different composite gain of crossing over the system operation bandwidth.

For realizing high-performance, often transmit pilot tone (being reference signal) and carry out multiple function with auxiliary receiver by transmitter.Usually according to knowing that code element produces pilot tone the sixth of the twelve Earthly Branches and to know that mode handles the sixth of the twelve Earthly Branches.Pilot tone can be received that machine is used for that channel estimating, timing and frequency are obtained, coherent demodulation, or the like.

Often need or be necessary in the signal that has received, to detect the existence of transfer of data.Usually realize that by be assumed to be the data transmission and processing pilot tone that has received for each transfer of data detects.If the energy of pilot tone is greater than specific thresholding, then further handle the transfer of data (as, demodulation sign indicating number) of hypothesis.Then, generally according to error detection code, Cyclic Redundancy Check for example determines that decoding to transfer of data is correctly or mistake.

In some radio communications systems, the detection according to pilot tone is inadequate separately.This may be following situation, for example, and when when low received signal to noise ratio (SNR) is gone up operation.In addition, error detection code may be for unreliable in order to the correctness of check reception transfer of data.

Therefore, needing in the art to be used in such radio communications system detects and demodulating data transmits technology.

Summary of the invention

The technology that is used in that wireless communication system detects and demodulating data transmits here is provided.In one aspect, provide (decision-directed) detector of a judgement-guidance, be used for detecting transfer of data at received signal.This detector uses the data accepted code element and received pilot frequency code element carries out detection, and therefore can provide improved detection performance.The detector of judgement-guidance is designed to operate in frequency domain or time domain.For the system that utilizes multi-carrier modulation (as OFDM), detector can be designed to carry out differential detection in frequency domain, or carries out coherent detection in time domain, and the both describes in detail below.

In yet another aspect, use adaptive threshold to carry out the detection that receives transfer of data.For being assumed to be the transfer of data that has received, each determines a thresholding.For example, can calculate thresholding based on the received signal gross energy (that is, signal plus noise adds interference) of the transfer of data of supposing.By utilizing adaptive threshold that healthy and strong detection performance can be provided in multiple operating environment, for example in the frequency band of the no licence that has various interference sources.

Illustrate in greater detail various aspects of the present invention and embodiment below.For example, the receiver structure that is used for various transmission plans has also been described here.

Description of drawings

Read following detailed description the in detail in conjunction with the accompanying drawings, it is more obvious that feature of the present invention, essence and advantage will become, and runs through accompanying drawing, and identical Reference numeral correspondingly identifies and wherein:

Fig. 1 has shown radio communications system;

Fig. 2 A and 2B have shown the exemplary protocol data cell (PDU) that is used for channel 1 and 2 respectively;

Fig. 3 A has shown the block diagram of transmitter unit;

Fig. 3 B has illustrated the OFDM code element;

Fig. 4 has shown the block diagram of receiver unit;

Fig. 5 has shown correlation detector;

Fig. 6 has shown an embodiment of correlation detector;

Fig. 7 has shown the detector/data demodulator of the detector that comprises data demodulator and judgement-guidance;

Fig. 8 A has shown the embodiment of data demodulator;

Fig. 8 B has shown the detector of carrying out the judgement-guidance of differential detection in frequency domain;

Fig. 8 C has shown the detector of carrying out the judgement-guidance of coherent detection in time domain;

Fig. 9 has shown the block diagram of access point and user terminal;

Figure 10 A and 10B have shown exemplary transmission on channel 1 and 2 respectively; And

Figure 11 A and 11B have shown the receiver processing that is used for channel 1 and 2 respectively.

Embodiment

Here the meaning of the word of Shi Yonging " exemplary " is " serving as example, example or example explanation ".Any embodiment or the design of describing as " exemplary " here there is no need to be understood that for other embodiment or design to be preferred or superior.

Fig. 1 has shown the radio communications system 100 that comprises a plurality of access points (AP) 110 of communicating by letter with a plurality of user terminals (UT) 120.(, in Fig. 1, only showing an access point 1) for for purpose of brevity.Access point also can be described as base station or other term.Each user terminal can be that fixed terminal or portable terminal and also can be described as accesses terminal, mobile radio station, distant station, subscriber equipment (UE), wireless device or other term.Each user terminal any particular moment all can with on down link and/or up link one or may communicate by a plurality of access points.Down link (that is, forward link) refers to the transmission from the access point to the user terminal, and up link (being reverse link) refers to the transmission from the user terminal to the access point.

The technology that is used to detect also demodulating data transmission of explanation here may be used to various wireless communication systems.For example, these technology can be used to satisfy the system of following condition, (1) use is one or more is used for the antenna of transfer of data and uses one or more antennas that are used for Data Receiving, (2) (for example use various modulation techniques, CDMA, OFDM, or the like), and (3) use one or more frequency bands for down link and up link.

For clarity, regarding to example wireless communication system illustrates present technique especially down.In this system, receiver is equipped with the antenna that a plurality of (T) are used for Data Receiving, and transmitter may possess one or more antennas.System further uses Orthodoxy Frequency Division Multiplex (OFDM), and it can become a plurality of (N) orthogonal subbands to the whole system bandwidth division effectively.For OFDM, at first use specific modulation scheme that the data or the pilot tone that transmit on each sub-band are modulated (promptly shining upon code element).For the sub-band that is not used for data/pilot transmission provides signal values of zero.For each OFDM code-element period, be used for the modulated symbol of whole N sub-frequency bands and signal values of zero and use inverse fast fourier transform (IFFT) to be transformed into time domain, with the conversion that obtains to comprise N time-domain sampling code element.In order to suppress inter symbol interference (ISI), the part of code element that often repeats each conversion is to form corresponding OFDM code element, and this OFDM code element is transmitted by wireless channel then.The OFDM code-element period (or simply, code-element period) corresponding to the cycle of an OFDM code element, it is the minimum unit of system transmissions.In a concrete design, system bandwidth is 20MHz, and N=64, sub-band are assigned with-32 to+31 index, and the duration of the code element of each conversion is 3.2 μ sec, and Cyclic Prefix is 800nsec, and the duration of each OFDM code element is 4.0 μ sec.

For clarity, the following describes two concrete transmission plans and two receiver structures.First transmission plan is used for transmission channel 1 (or simply, channel 1 or CH1) and have following feature: (1) on channel 1 be transmitted in the transmitter place not free-compensation, and arrive receiver in the unknown time, and (2) each transmission on channel 1 comprises a plurality of OFDM code elements that are used for data and pilot tone.Second transmission plan is used for transmission channel 2 (or simply, channel 2 or CH2) and have following feature: (1) on channel 2 be transmitted in the transmitter place have time-compensation and arrive the receiver place with boundary of time slot time unifying ground, and (2) each transmission on channel 2 comprises the single OFDM code element that is used for data and pilot tone.The low speed and the quick Random Access Channel that have with channel 1 and 2 similar characteristics have been described in above-mentioned U.S. Patent application 60/432,440.

Fig. 2 A shows the exemplary protocol data cell (PDU) 210 that can be used for channel 1 (CH1 PDU).CH1 PDU 210 comprises the reference part 220 with CH1 message part 230 Time Division Multiplexing.Reference part 220 comprises P pilot tone OFDM code element 222, and P can be any integer of one that is equal to or greater than.Promote the acquisition of CH1 transmission and the coherent demodulation of detection and assistance CH1 message part with pilot tone OFDM code element.CH1 message part 230 comprises D data OFDM code element 232, and wherein D can be one or any greater than one integer.Can produce pilot tone and OFDM data code element as described below.

Fig. 2 B has shown the exemplary PDU 250 (CH2 PDU) that can be used to channel 2.CH2 PDU250 comprises the reference part 260 multiplexed with CH2 message part 270 sub-bands.Reference part 260 is included in one group of sub-band (as the shade sub-band that shows at Fig. 2 B) and goes up the one group of pilot frequency code element that transmits.CH2 message part 270 comprises one group of data symbols that transmits on another group sub-band.By coding, interweave, and symbol mapped CH2 message 280 produces data symbols.As described below, the multiplexed pilot of processing frequency domain multichannel and data symbols are to produce time domain CH2 PDU250.

Among the embodiment that shows in Fig. 2 B, the pilot subband that interweaves and data subbands are so that the two ends of pilot subband and each data subbands join.The pilot frequency code element that transmits on pilot subband can be used to estimate channel response for data subbands and coherent demodulation.Also can realize other sub-band multiplexing scheme, and these within the scope of the present invention.For example, pilot subband can be in the both sides of every group of Q data subbands, and wherein Q can be any positive integer.

Fig. 3 A has shown the block diagram of carrying out the embodiment of the transmitter unit 300 that sends data processing as mentioned above for channel 1 and 2.The transmitter unit 300 that can realize in access point or user terminal comprises transmission (TX) data processor 310, optional TX spatial processor 330 and be used for the OFDM modulator 340 that each transmits antenna.

In TX data processor 310, CRC generator 312 be CH1 or CH2 message sink data also (optionally) be that message produces crc value.Encoder 314 is encoded to message data and crc value (if being included) according to specific encoding scheme then, so that bits of coded to be provided.Interleaver 316 is next according to specific interleaving scheme (that is, the rearranging) bits of coded that interweaves, so that frequency and possible time diversity to be provided.The data that symbol mapped unit 318 interweaves according to specific modulation then are to provide modulated symbol, and this modulated symbol is also referred to as data symbols and is expressed as s (k).

Multiplexer (MUX) 320 thinks that the CH1 of present or the mode of CH2 message definition receive and multiplexed data code element and pilot frequency code element.For the embodiment that shows among Fig. 2 A, CH1 PDU comprises P the pilot tone OFDM code element of being followed by D data OFDM code element.For CH1 message, multiplexer 320 is provided for each data symbols of D data OFDM code element then for each of P pilot tone OFDM code element provides one group of pilot frequency code element { p1 (k) }.For the embodiment that is presented among Fig. 2 B, CH2 PDU comprises L+1 pilot frequency code element with L data symbol interleave.For CH2 message, multiplexer 320 provide one group with one group of L+1 pilot frequency code element { P2 (k) } that L data code element is multiplexed.Under any circumstance, multiplexer 320 provides multiplexed data and pilot code flow filament.

Table 1 has shown the two groups of pilot frequency code elements { p1 (k) } that are used for CH1 and CH2 reference part and the specific embodiment of { P2 (k) }.In this embodiment, altogether in 64 sub-frequency bands only 52 be used for data and pilot transmission, and do not use other 12 sub-bands (in table 1, have zero list item).In an embodiment, pilot frequency code element is the QPSK modulated symbol.Selection is used for 52 pilot frequency code elements of CH1 reference part so that the waveform that produces according to this pilot frequency code element has minimum crest to average deviation.This feature allows to transmit pilot tone OFDM code element on higher power level, and this can improve performance.

Table 1-is used for the pilot frequency code element of CH1 and CH2

Sub-band index	Pilot frequency code element P1 (k)	CH1 pilot frequency code element P2 (k)	Sub-band index	CH1 pilot frequency code element P1 (k)	CH1 pilot frequency code element P2 (k)	Sub-band index	CH1 pilot frequency code element P1 (k)	CH1 pilot frequency code element P2 (k)	Sub-band index	CH1 pilot frequency code element P 1(k)	CH1 pilot frequency code element P 2(k)
												-32	0	0	-16	-1+j	Data		0	0	0	16	-1+j	Data
-31	0	0	-15	1-j	1+j	1	1-j	-1-j	17	-1+j	1-j
												-30	0	0	-14	1+j	Data	2	-1-j	Data	18	1-j	Data
-29	0	0	-13	1-j	1+j	3	-1-j	-1-j	19	1+j	-1-j
												-28	0	0	-12	1-j	Data	4	-1-j	Data	20	-1+j	Data
-27	0	0	-11	-1-j	1+j	5	-1+j	1+j	21	1+j	-1-j
												-26	-1-j	-1+j	-10	-1-j	Data		6	1+j	Data	22	-1+j	Data
-25	-1+j	-1+j	-9	1-j	1-j	7	-1-j	-1-j	23	1+j	-1-j
												-24	-1+j	Data	-8	-1-j	Data	8	-1+j	Data	24	-1+j	Data
-23	-1+j	-1-j	-7	1+j	-1+j	9	-1-j	1-j	25	1-j	-1+j
												-22	1-j	Data	-6	-1+j	Data	10	-1-j	Data	26	-1-j	1-j
-21	1-j	-1-j	-5	-1-j	-1-j	11	1+j	1+j	27	0	0
												-20	1+j	Data	-4	-1+j	Data		12	1-j	Data	28	0	0
-19	-1-j	-1-j	-3	-1+j	-1+j	13	-1+j	1-j	29	0	0
												-18	-1+j	Data	-2	1-j	Data	14	-1-j	Data	30	0	0
-17	1+j	1+j	-1	-1+j	-1+j	15	1+j	-1+j	31	0	0

If a plurality of antennas can be used, then optional TX spatial processor 330 can be used to carry out spatial manipulation on multiplexed data and pilot frequency code element.For example, TX spatial processor 330 can be carried out following spatial manipulation, this processing is used for (1) wave beam-guiding or wave beam forms to send code element on the single space channel of mimo channel, (2) send diversity on a plurality of antennas and sub-band, transmitting code element realizing diversity, or (3) spatial multiplexing is to send code element on a plurality of space channels.In above-mentioned U.S. Provisional Application 60/421,309, describe the spatial manipulation that is used for all these transmission meanss in detail.

TX spatial processor 330 provides one to send code element stream for each antenna.If do not carry out spatial manipulation, sending code element only is multiplexed data and pilot frequency code element.For providing each, each OFDM modulator 340 sends code element stream.In each OFDM modulator 340, inverse fast Fourier transform (IFFT) unit 342 becomes the code element of being made up of N time-domain sampling through spatial transform to each sequence transformation that N transmits code element, and wherein N is the sum of sub-band.For the code element of each conversion, the part of Cyclic Prefix generator 344 repeated transformation code elements is to form the corresponding OFDM code element of being made up of M sampling.Cyclic Prefix generator 344 provides OFDM code element stream to transmitter (TMTR) 346, this transmitter converts the OFDM code element stream to one or more analog signals and further amplifies, filter, and the up-conversion analog signal sends this RF modulation signal from relevant antenna 350 then to produce the RF modulation signal.

Fig. 3 B explanation OFDM code element, it is made up of two parts: Cyclic Prefix and through the code element of conversion.In an embodiment, N=64, Cyclic Prefix comprise 16 samplings, and each OFDM code element comprises M=80 sampling.Cyclic Prefix is the duplicating of last 16 samplings (that is, the cycle continuity) of the code element of conversion, and is inserted into the front of the code element of conversion.Cyclic Prefix guarantees that the OFDM code element keeps its orthogonality under the situation of multipath delay expansion.

Figure 10 A is presented at the transmission of demonstration on the channel 1.The timeline that is used for channel 1 is divided into the CH1 time slot, and each CH1 time slot has the specific duration (for example, P+D OFDM code-element period).In an embodiment, can on each CH1 time slot, transmit a CH1 PDU.

User terminal A and B are their timing and frequency lock time and the frequency to system.Carry or embed the transmission (for example, beacon pilot frequency) of timing information by reception.User terminal is provided with their time then according to the timing information that receives.Yet the timing of each user terminal may depart from (or postpone) with respect to system time, and the numerical value that wherein departs from is usually corresponding to the propagation delay of the transmission that comprises timing information.If user terminal and system all (for example, GPS) derive their timing, then may not have timing slip between these entities from common time source.

In Figure 10 A, user terminal A and B (for example, select two different CH1 time slots (for example, being respectively time slot 3 and 1) to send their CH1 PDU randomly).Because user terminal A and B are associated with different timing slip and different propagation delays, their CH1 PDU arrives access point (being called round trip delay or RTD) with the CH1 boundary of time slot with respect to access point with different delays.

Figure 10 B has shown the transmission of demonstration on channel 2.The timeline that is used for channel 2 is divided into the CH2 time slot, and each CH2 time slot has the specific duration (for example, OFDM code-element period).On each CH2 time slot, transmit a CH2 PDU.

For Figure 10 B, user terminal A and B their system that timely locks regularly and further known their RTD (for example, between system's access periods) that is determined by access point and have returned report to user terminal.After this user terminal can adjust them transmission regularly to consider their RTD, make their CH2 PDU arrive access point in the time of selected CH2 boundary of time slot at time unifying.In Figure 10 B, user terminal A and B (for example, randomly) select CH2 time slot 3 and 1 to send their CH2 PDU respectively.Because user terminal A and B time bias their transmission, shown in Figure 10 B, CH2 PDU arrives access point about time on the border that is aligned in selected CH2 time slot greatly.

Fig. 4 has shown the block diagram of carrying out the embodiment of the receiver unit 400 that receives data processing as mentioned above for channel 1 and 2.Receiver unit 400 can be realized it in access point or user terminal, it comprises and is used for each a receiver (RCVR) 410 of T reception antenna 408, detector/data demodulator 420, and receive (RX) data processor 450.

Each antenna 408 receives the RF modulation signal that is sent by transmitter unit, and provides received signal to receiver 410 separately.Each receiver 410 makes its received signal meet the requirements of condition (for example, amplify, filter, and frequency down conversion), and the signal that digitlization satisfies condition to be to provide sampling, and sampled representation is x _i(n).

Detector/data demodulator 420 comprises data demodulator 430 and detector 440, and this detector receives and handle the sampling from all receivers 410, to detect and the transfer of data of demodulation on channel 1 and 2.Illustrate further the processing of unit 420 below.Unit 420 provides the data recovered code element, is expressed as

, it is to sending the estimation of data symbols s (k).In RX data processor 450, the data recovered code element is separated mapping by symbol de-maps unit 452, is deinterlaced by deinterleaver 454, and by decoder 456 decodings, with the data of the decoding that is provided for CH1 and CH2 message.If the message of recovering comprises crc value, then CRC verifier 458 is with the crc value verification message, to determine that whether correctly or decoded mistakenly it.

Figure 11 A shows the receiver processing of the channel 1 that is used for not free compensation.Refer back to Figure 10 A, though transmitter unit is attempted to send on specific CH1 time slot, the CH1 transmission is not free to be compensated, and the synthetic performance of channel 1 is similar to the channel of unallocated time slot.In this case, refer back to Figure 11 A, receiver unit can use the slip correlation detector, and to detect the CH1 transmission, each CH1 transmission can be received when any sampling period begins.

The correlation detector that can operate in time domain slips over whole time intervals that can receive CH1 PDU therein, whenever next sampling period.The sampling of a CH1 PDU of detection window indication will be by the time cycle of detector processes.This detection window can be initialised to the beginning of first CH1 time slot, and subsequently with sampling period of each front slide.For each sampling period with respect to a hypothesis, correlation detector is handled the sampling in detection window, with the tolerance of the CH1 PDU of the hypothesis determining to have received since the sampling period.If should tolerance surpass the CH1 thresholding, the CH1 PDU that then further decodes is to recover CH1 message.This tolerance can relate to signal energy or other parameter.The CH1 thresholding may be (for example, dynamically determining according to the sampling in detection window) that fix or adaptive.

Fig. 5 shows the block diagram of correlation detector 440a, and correlation detector 440a is an embodiment of the detector 440 in Fig. 4.Each sampling x of T reception antenna is provided respectively for separately antenna processing device 510 _i(n).In each processor 510, symbol accumulator 520 receive and the add up sampling that is used for current hypothesis and the sampling that adds up is provided for delay line/buffer 530

For the CH1 PDU that is presented among Fig. 2 A, symbol accumulator 520 is carried out adding up of P pilot tone OFDM code element, wherein carries out on each sampling basis and adds up, so that the pilot tone OFDM code element that adds up with M sampling to be provided.Delay line/buffer 530 is provided for the individual memory of N in M the sampling, and abandons M-N the sampling that is used for Cyclic Prefix effectively.These N samplings are used for the code element that is transformed corresponding to the pilot tone OFDM code element that adds up.

Signal detector 540 is identified for the tolerance of the pilot tone OFDM code element that adds up then.In an embodiment and as described below, measure relevant with the signal energy of N sampling of the pilot tone OFDM code element that is used to add up.Yet, also spendable other tolerance, and these are within the scope of the present invention.Adaptive threshold computing unit 550 is determined an adaptive threshold Y _i(n), to be used to determine whether to have received the CH1 transmission.The threshold value summation of 560 pairs of all T antennas of adder is to provide the thresholding of combination, and it can further have multiplier 562 scale factor convergent-divergent, to obtain final thresholding Y (n).The metric summation of 564 pairs of all T antennas of adder is to provide final metric value E (n), and this final metric value is by comparator 570 and last thresholding Y (n) comparison then.If E (n)〉Y (n), detector output will be indicated and received CH1 PDU, otherwise then not receive CH1 PDU.

Fig. 6 shows the block diagram of correlation detector 440b, and correlation detector 440b is the embodiment of the detector 440a in Fig. 5.The sampling x of each reception antenna _i(n) be provided for symbol accumulator 520, it is realized with P-1 delay cell 522 and P-1 adder 524.Each delay cell 522 provides the OFDM code element (being M sampling) of a delay.P-1 adder 524 is carried out adding up of P pilot tone OFDM code element on the basis of each sampling, and the sampling of the last adder pilot tone OFDM code element that is provided for adding up

Sampling

Can be expressed as:

${\tilde{x}}_i\left(n\right)=\underset{j=0}{\overset{P-1}{\mathrm{\Σ}}}(n-\mathrm{jM})$ For i ∈ { 1 ... T} equation (1)

Sampling

Be provided for delay line/buffer 530, it is to realize that with N-1 delay cell 532 each delay cell provides the delay in a sampling period.

Signal detector 540 is carried out the relevant of the pilot tone OFDM code element that adds up and known pilot OFDM code element, and the metric E of the pilot tone OFDM code element that is identified for adding up _i(n).N sampling of the pilot tone OFDM code element that each is used to add up is provided for each multiplier 542, and this multiplier also receives grips pilot samples accordingly altogether

, j ∈ { 0..N-1} wherein.In order to obtain

, use a N point IFFT will be used for the pilot frequency code element set { p of pilot subband ₁(k) } and be used for not using the signal values of zero (for example as shown in the table 1) of sub-band to transform to time domain, obtain the N point sampling

Arrive

, subsequently with their conjugation and offer N multiplier 542.Each multiplier 542 is with its sampling

With its conjugation pilot samples

Multiply each other, and the result is offered adder 544.Adder 544 will be from the results added of all N multiplier 542, and the result of addition is offered a unit 546.The square number magnitude of addition result is determined in unit 546, and it is as metric E _i(n).The metric that is used for each antenna can be expressed as:

$E_i\left(n\right)={|\underset{j=0}{\overset{N=1}{\mathrm{\Σ}}}{{\tilde{p}}^{*}}_1\left(j\right)\·{\tilde{x}}_i(n-j)|}^2$ For i ∈ { 1 ... T} equation (2)

Adder 564 receives and the metric of all T antenna is sued for peace, and so that final metric value E to be provided (n), it can be expressed as:

$E\left(n\right)=\underset{i=1}{\overset{T}{\mathrm{\Σ}}}{E}_i\left(n\right)$ Equation (3)

Threshold computation unit 550 determines that adaptive threshold is used for the CH1 PDU of current hypothesis in order to detection.The N sampling of the pilot tone OFDM code element that each is used to add up is provided for each unit 552, and the squared magnitude of sampling is determined in unit 552.Adder 554 is sued for peace so that threshold value Y to be provided to the squared magnitude from all N unit 552 then _i(n).Adder 560 receives and the threshold value of all T antenna is sued for peace, so that the threshold value Y of combination to be provided _Tot(n), it can be expressed as:

$Y_{\mathrm{tot}}\left(n\right)=\underset{i=1}{\overset{T}{\mathrm{\Σ}}}\underset{j=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|{\tilde{x}}_i(n-j)\right|}^2$ Equation (4)

Multiplier 562 then with the threshold value of scale factor convergent-divergent combination so that final threshold value to be provided, it can be by Y (n)=S ₁Y _Tot(n) provide.

Comparator 570 compares final metric value E (n) and final threshold value Y (n), and detector output D (n) is provided, and it can be expressed as:

$D\left(n\right)=\left\{\begin{array}{cc}\&prime;\&prime;\mathrm{<figure-callout\; id="1"\; label="CH"\; filenames="A200810178647E00281.png,A200810178647E00291.png"\; state="\{\{state\}\}">CH</figure-callout>}1\mathrm{PDU\; present}\&prime;\&prime;& \mathrm{if\; E}\left(n\right)>Y\left(n\right)\\ \&prime;\&prime;\mathrm{<figure-callout\; id="1"\; label="CH"\; filenames="A200810178647E00281.png,A200810178647E00291.png"\; state="\{\{state\}\}">CH</figure-callout>}1\mathrm{PDU\; not\; present}\&prime;\&prime;& \mathrm{otherwise}\end{array}\right.$ Equation (5)

If detect CH1 PDU, the time instant that detects at CH1 PDU is provided with OFDM symbol timing (that is, when detecting CH1 PDU, at the particular value of n) then.

Scale factor S1 is positive constant, select this positive constant so that (1) specific false dismissal probability to be provided, promptly do not detect the probability of the CH1 PDU that has transmitted and specific false alarm rate, i.e. indication when in fact not transmitting and phonily receives the probability of CH1 PDU.We wish false dismissal probability less than message error rate (MER), so that MER determines by the SNR and other parameters that receive, rather than are determined by detector.Can be in particular channel 1 and determine MER, for example be percent 1 or still less.Detector output may be used for determining whether to handle the CH1 message of CH1 PDU to recover to transmit of reception.Judge the CH1 message of whether correctly or mistakenly decoding according to the crc value that is included in the message.

For the given CH1 of reception PDU, correlation detector might be announced a plurality of detections.This is to have noise because of working as in one or more OFDM code element, and is being used for just announcing when there is signal in another OFDM of detected CH1 PDU detection.For example, when P=2, OFDM code element 1 can take place first and detect when having noise and having signal in OFDM code element 2, and when the OFDM code-element period arrival after a while of secondary signal OFDM code element, will have second of bigger final metric value and detect.Therefore, for P〉1, detector can be operated and think that additional P-1OFDM code-element period continues to detect the final metric value of CH1 PDU with the maximum of discovery PDU.By detection the OFDM symbol timing is set then with maximum final metric value, and also according to detecting relevant Time Calculation RTD therewith.

Can be independent of Message Processing and carry out testing process,, can normal mode continue to detect processing promptly no matter whether detect CH1 PDU.Therefore, if detect CH1PDU at first and detect another CH1 PDU at sampling period n with final metric value after a while with final metric value E (n-j) in the sampling period, E (n) wherein〉E (n-j), and j is less than the size of detection window, then may stop to be used for current Message Processing, and handle with the CH1 PDU that detects at sampling period n and to replace at the detected CH1 PDU of sampling period n-j.

Figure 11 B has shown the receiver processing of the channel 2 that is used for time bias.Refer back to Figure 10 B, transmitter unit transmits on specific CH2 time slot, and CH2 transmission is time bias, to arrive receiver unit at the CH2 boundary of time slot of selecting.In this case, refer back to Figure 11 B, receiver unit can detect the CH2 transmission in each CH2 time slot (rather than each sampling period), and detection window can move from the time slot to the time slot.For each CH2 time slot corresponding to hypothesis, the sampling that the detector processes of judgement-guidance receives in detection window is to determine in that time slot tolerance of the CH1 PDU of received hypothesis.If should tolerance surpass the CH2 thresholding, CH2 PDU is considered to receive so.

Fig. 7 has shown the block diagram of the embodiment of detector/data demodulator 420c, and it also is used in the unit 420 among Fig. 4.Detector/data demodulator 420c comprises the data demodulator 430c that is used to carry out coherent demodulation and is used to detect the detector 440c of judgement-guidance of CH2 PDU.Detector 750 to corresponding antenna demodulator 710 and judgement-guidance accordingly in detector 440c in data demodulator 430c provides every T the sampling of a reception antenna.

Each antenna demodulator 710 is the coherent demodulation that an antenna is carried out the OFDM code element that is used for a reception at every turn.For the OFDM code element of each reception, FFT unit 712 receives the sampling x that is used for the OFDM code element _i(n), remove the code element of Cyclic Prefix, and the code element r of fast Fourier transform (FFT) to provide N to receive is provided on the code element of conversion with the acquisition conversion _i(k), they comprise the data symbols r of reception _{I, d}(k) and the pilot frequency code element r that receives _{I, p}(k).720 pilot frequency code element r of channel-estimator according to reception _{I, p}(k) come the channel response of data estimator sub-band.Demodulator 730 is carried out and is received data symbols r _{I, d}(k) with the coherent demodulation of channel estimating, so that the data recovered code element to be provided

Symbol accumulator 740 is that T reception antenna receives and the data recovered code element that adds up from demodulator 710a to 710t, and the code element of recovery is provided

As above according to Fig. 4,450 of RX data processors are handled the code element of recovering

, so that the data of decoding to be provided.In an embodiment, CH2 message does not comprise CRC, and the CRC check is not carried out by the RX data processor.310 of TX data processors are handled the data of decoding so that the code element c (k) of modulation once more to be provided, and it is the estimation of the data symbols s (k) of transmission.As above be that Fig. 3 A is described, the processing of processor 310 comprises coding, interweave, and symbol mapped.The processing of RX data processor 450 often is called " decoding " simply, and the processing of TX data processor 310 often is called " coding again ".

The detector 750 of each judgement-guidance is that the OFDM code element of a reception is carried out detection at every turn.For the OFDM code element of each reception, FFT unit 752 receives the sampling x of OFDM code element _iAnd on the code element of corresponding conversion, carry out FFT (n), so that the code element r of N reception to be provided _i(k).Usually realize FFT unit 712 and 752, but, be shown as two unit at Fig. 7 for for the purpose of clear with FFT unit.

760 code elements with their expectation of signal detector are handled the pilot tone and the data symbols of reception, with the tolerance E that just is provided in processed OFDM code element _i' (n).Whether adaptive threshold computing unit 770 is identified for judging the received adaptive threshold Y of CH2 PDU _i' (n).The thresholding summation of 780 pairs of all T antennas of adder is to provide the threshold value Y of combination _Tot' (n), the threshold value that multiplier 782 should make up with scale factor 2 further convergent-divergents is to obtain final threshold value Y ' (n).The metric summation of 784 pairs of all T antennas of adder is to provide final metric value E ' (n), and this final metric value is by comparator 790 and last thresholding Y value then ' (n) relatively.If E ' is (n)〉Y ' (n), detector output will be indicated and received CH2 PDU, otherwise not receive CH2 PDU.

Fig. 8 A has shown the block diagram of data demodulator 430d, and data demodulator 430d is the embodiment of the data demodulator 430c in Fig. 7.Sampling x by FFT unit 712 each reception antenna of conversion _i(n), the code element of thinking each conversion provides N code element r that receives _i(k).For the embodiment that is presented in the table 1, N code element that receives comprises the pilot frequency code element of 28 receptions of 28 pilot subband, be used for 24 data sub-bands 24 receptions data symbols and be used for 12 additional code elements of 12 untapped sub-bands.For the sake of simplicity, following explanation is about being presented at the embodiment among Fig. 2 B, wherein N code element that receives comprises that L+1 the pilot frequency code element that receives that is used for L+1 pilot subband receives data with L that is used for L data sub-band, wherein pilot subband and each data subbands both sides join, and the sub-band index k that is used for pilot tone and data subbands is defined as wherein K={1...49} of k ∈ K.

Carry out each the coherent demodulation of L data sub-band by at first using two pilot subband of joining with the data subbands side to make an estimate as the data subbands channel response.Can obtain to be used for the channel estimating of k data sub-band by the pilot subband channel estimating that combination is used for both sides

, this can be expressed as:

${\hat{h}}_i\left(k\right)={\hat{h}}_i(k-1)+{\hat{h}}_i(k+1)$

$={{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="A200810178647E00321.png,A200810178647E00341.png"\; state="\{\{state\}\}">p</figure-callout>}}_2}^{*}(k-1)r_i(k-1)+{{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="A200810178647E00321.png,A200810178647E00341.png"\; state="\{\{state\}\}">p</figure-callout>}}_2}^{*}(k+1)r_i(k+1),k\&Element;K_d,$ And i ∈ { 1...T}, equation (6)

P wherein ₂(k) be the pilot frequency code element that on the k sub-frequency bands that is used for channel 2, transmits, and K _dThe set of expression data subbands, i.e. K _d∈ 2,4 ... 2L}.

The data recovered code element of each data subbands

Can be expressed as:

, to k ∈ K _dAnd i ∈ { 1...T} equation (7)

Can be the data recovered code element that each data subbands obtains all T reception antenna:

K ∈ K _d, equation (8)

In Fig. 8 A, L+1 multiplier 722 and L adder 724 are carried out the channel estimating that is presented in the equation (6).Each multiplier 722 multiply by the conjugation of the code element of the pilot tone of knowing in the sixth of the twelve Earthly Branches of being used for sub-band to the code element of the reception of corresponding pilot subband, so that the channel estimating of pilot subband to be provided.724 of each adders are to two pilot subband summations in related data sub-band side, so that the channel estimating to this data subbands to be provided.Can obtain simultaneously the channel estimating of L data sub-band, and this is within the scope of the invention according to other mode of interpolation method or some.

L multiplier 732 carried out the coherent demodulation that is presented in the equation (7).Each multiplier 732 is the r of receiving symbol of corresponding data subbands _i(k) multiply by the conjugation of the channel estimating that is used for sub-band

, so that the data recovered code element of data subbands to be provided

Shown in equation (8), the sampling of each of L adder 742 all T of execution reception antenna adds up.Each adder 742 receives and to T data recovered code element of T reception antenna of the data subbands that is used to be associated

Summation is with the code element s (k) of recovery that sub-band is provided.

As mentioned above, sub-band is multiplexed can be so that the both sides of Q data sub-band of each group and pilot subband join, and wherein Q may be greater than one.If Q〉1, then can carry out coherent demodulation in a number of ways.In one embodiment, the pilot frequency code element that each pilot subband receives is used as the coherent reference that is used for two adjacent data sub-bands, and can be according to the pilot frequency code element of this reception reception data symbols of these data subbands of demodulation coherently.Can obtain hard decision then and use hard decision to remove modulation, to obtain the improved channel estimating of follow-up two data sub-bands with data symbols from firm detection.Can be from end data subbands (that is, and then pilot subband) beginning demodulation process, and continue to handle and reach the intermediate data sub-band.When detection receives every pair of code element of data, can obtain to be used for improved channel estimating away from the data subbands of pilot subband.In another embodiment, the pilot frequency code element of the reception of every pair of pilot subband of interpolation is to obtain each channel estimating of Q data sub-band that the pilot subband side joins.

Whether the message of crc value through being usually used in determine receiving is correctly or decoded mistakenly.In some cases, we wish to comprise crc value in message, because overhead relevant with crc value and/or other consideration.In this case, need another mechanism whether effective to determine the message that receives.In the embodiment that shows among Fig. 7, but operating data demodulator 430c and RX data processor 450 provide the message of decoding for each hypothesis, and can operations detector 440c, to provide for hypothesis whether the received indication of message is arranged.

Fig. 8 B is presented in the frequency domain and carries out differential detection and be the block diagram of detector 440d of judgement-guidance of the embodiment of the detector 440c in Fig. 7.Sampling x by FFT unit 752 each reception antenna of conversion _i(n) come to provide N code element r that receives for the code element of each conversion _i(k).

For the metric E ' of the code element of determining each conversion (n), at first obtain a detection statistic g by the real part by 2L the dot product that uses adjacent a pair of pilot tone and data subbands to form is summed to each reception antenna _i(n).Detection statistic g _i(n) can be expressed as:

$g_i\left(n\right)=\underset{\mathrm{ki}=1}{\overset{2L}{\mathrm{\&Sigma;}}}z\left(k\right)\&CenterDot;z^{*}(k+1)$ For i ∈ { 1 ... T} equation (9a)

Wherein

$z_i\left(k\right)=\left\{\begin{array}{cc}{r}_i\left(k\right)\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="A200810178647E00321.png,A200810178647E00341.png"\; state="\{\{state\}\}">p</figure-callout>}}_2^{*}\left(k\right)& \mathrm{for\; k}\&Element;(\mathrm{1,3},...2L+1)\\ r_i\left(k\right)\&CenterDot;c^{*}\left(k\right)& \mathrm{for\; k}\&Element;(\mathrm{2,4},...2L)\end{array}\right.---b)$

The metric E ' of conversion code element (n) can be expressed as:

$E\&prime;\left(n\right)={\left|\underset{i-1}{\overset{T}{\mathrm{\&Sigma;}}}\mathrm{Re}\left\{g_i\left(n\right)\right\}\right|}^2$ For i ∈ { 1 ... T} equation (10a)

Select as another kind, metric E ' (n) can be expressed as:

$E\&prime;\left(n\right)=\underset{i-1}{\overset{T}{\mathrm{\&Sigma;}}}{\left|\mathrm{Re}\left\{g_i\left(n\right)\right\}\right|}^2$ For i ∈ { 1 ... T} equation (10b)

In Fig. 8 B, 2L+1 multiplier 762,2L multiplier 764 and adder 766 are carried out the detection statistics g that is presented in the equation (9) _i(n) calculating.Each multiplier 762 multiply by the pilot frequency code element known the sixth of the twelve Earthly Branches or the conjugation of the code element of modulation again of that sub-band to the code element of the reception of relevant pilot tones or data subbands.Each multiplier 764 is carried out from the dot product of the output of a pair of multiplier 762 of a pair of adjacent pilot frequencies and data subbands.766 of adders are to from 764 summations of L multiplier, so that detection statistic g to be provided _i(n).For the embodiment that is presented in the equation (10a), unit 768 receives g _i(n) and to adder 784 provide real part, the real part summation of 784 pairs of all T antennas of adder.Ask square to provide metric E ' (n) by 786 pairs of the outputs in unit from adder 784.For the embodiment that is presented in the equation (10b), unit 786 can be placed between unit 768 and the adder 784.

Adaptive threshold computing unit 770 be identified for each reception the conversion code element adaptive threshold Y ' (n).Each of 2L+1 receiving symbol ri (k) of pilot tone and data subbands is provided to each unit 772 of the squared magnitude of determining code element.Adder 774 is sued for peace so that thresholding Y ' to be provided value to the squared magnitude of all 2L+1 unit 772 then _i(n).Adder 780 receives and the thresholding of all T antenna is sued for peace, so that the threshold value Y of combination to be provided _Tot(n), it can be expressed as:

${Y\&prime;}_{\mathrm{tot}}\left(n\right)=\underset{i-1}{\overset{T}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{2L+1}{\mathrm{\&Sigma;}}}{\left|r_i\left(k\right)\right|}^2$ Equation (11)

Multiplier 782 with the threshold value of scale factor S2a convergent-divergent combination so that final threshold value to be provided, it can by Y ' (n)=S.Y _Tot' (n) provide.Usually, the duration of the PDU that will detect add up each threshold value Y ' (n) and metric E ' (n).Therefore, if PDU crosses over a plurality of OFDM code-element periods, at first be each calculating thresholding and metrics of these OFDM code elements then as mentioned above, add up then so that final thresholding and the metric of PDU to be provided.

Comparator 790 (n) (n) compares final metric value E ' with final threshold value Y ', and provides detector output D ' (n), and it can be expressed as:

$D\&prime;\left(n\right)=\left\{\begin{array}{cc}\&prime;\&prime;\mathrm{<figure-callout\; id="2"\; label="CH"\; filenames="A200810178647E00321.png,A200810178647E00341.png"\; state="\{\{state\}\}">CH</figure-callout>}2\mathrm{PDU\; present}\&prime;\&prime;& \mathrm{if\; E}\&prime;\left(n\right)>Y\&prime;\left(n\right)\\ \&prime;\&prime;\mathrm{<figure-callout\; id="2"\; label="CH"\; filenames="A200810178647E00321.png,A200810178647E00341.png"\; state="\{\{state\}\}">CH</figure-callout>}2\mathrm{PDU\; not\; present}\&prime;\&prime;& \mathrm{otherwise}\end{array}\right.$ Equation (12)

If detector output D ' (n) indicate and has CH2 PDU, then the CH2 message of being decoded by the RX data processor is considered to effectively also, and depends on the circumstances and can further be handled by controller.Otherwise CH2 message is dropped.

Fig. 8 C is presented in the time domain and carries out coherent detection and be the block diagram of detector 440e of judgement-guidance of another embodiment of the detector 440c in Fig. 7.The sampling x of each reception antenna is provided to delay line/buffer 830 of realizing with N-1 delay cell 832 _i(n), each delay element provides the sampling period of a delay.

The OFDM code element that detector 440e carries out each reception is relevant with its corresponding " reconstruct " OFDM code element, thinks that the OFDM code element of reception is determined to measure E " (n).The N sampling x of the OFDM code element that is provided for receiving to corresponding multiplier 842 _i(n) each, multiplier 842 also receives the reconstructed sample d of corresponding conjugation ^*(j), j ∈ { 0...N-1} wherein.For obtaining d ^*The pilot frequency code element p that (j), will be used for pilot subband by a N point IFFT 830 ₂(k) (for example as shown in table 1), the c of modulated symbol again (k) that is used for data subbands, with be used for the OFDM code-element period do not use sub-band signal values of zero (N the code element that promptly is used for N total sub-channel) transform to time domain, arrive d (N-1) to obtain N reconstructed sample d (0), they are subsequently by conjugation and offer N multiplier 842.The operation that other elements among Fig. 8 C are carried out is as above described to Fig. 6.The metric E that is used for each antenna " (n) can be expressed as:

$E\&prime;\&prime;\left(n\right)={|\underset{j=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{d}^{*}\left(j\right)\&CenterDot;x_i(n-j)|}^2$ I ∈ { 1 ... T} equation (13)

The final metric value E that is used for all T antenna " (n) can be represented as:

$E\&prime;\&prime;\left(n\right)=\underset{i=1}{\overset{T}{\mathrm{\&Sigma;}}}{E\&prime;\&prime;}_i\left(n\right)$ Equation (14)

Be used for final metric value E " (n) Bi Jiao threshold value Y " (n) can be as come determining to Fig. 6 is described.Especially, the composite door limit value Y that is used for all T antenna " _Tot(n) can be expressed as:

${Y\&prime;\&prime;}_{\mathrm{tot}}\left(n\right)=\underset{i=1}{\overset{T}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{\left|x_i(n-j)\right|}^2$ Equation (15)

Final threshold value can be by Y " (n)=S _2bY _Tot" (n) provide.

For the detector of judgement-guidance, scale factor S ₂(for the detector 440d in Fig. 8 B is S _2aAnd be S for the detector 440e in Fig. 8 C _2b) be positive constant, select this constant to be used for the specific false alarm rate that the specific false dismissal probability of CH2 PDU and (2) announce to exist CH2 PDUs improperly so that (1) to be provided.If define CH2 message like this,, then only rely on detector to determine whether to exist CH2 message so that they do not comprise crc value.Because underlying cause may provide wrong CH2 message to controller:

● false-alarm---noise in the received signal is detection trigger phonily; With

● incorrect decoding---the signal trigger detection correctly still CH2 message of decoding comprises uncorrected and undetected mistake.

If channel 2 is used as Random Access Channel, then the false-alarm of CH2 PDU can cause system to non-existent user terminal Resources allocation, and this will cause the wasting of resources.Under the sort of situation, we wish selection percentage factor s ₂To minimize false alarm probability, because we do not wish that noise triggers the waste resource frequently.

Incorrect decoding probability is relevant with detection probability, and the higher detection probability can cause more incorrect decoded events.When incorrect decoded events takes place, provide the CH2 message of decoding mistakenly to controller.Perhaps, controller can be checked the validity of CH2 message in certain other mode.For example, if CH2 message comprises the unique identifier of the user terminal that is used to transmit message, then whether controller can check the CH2 message unique identifier of recovery to be included in effective identifier list.If the unique identifier in the CH2 message of determining to receive is that effectively then system can be to the user terminal Resources allocation relevant with that identifier.

At scale factor S ₂Selection in, when false alarm probability and incorrect decoding probability were kept below specific level, we wished as far as possible effective CH2 message that detect more.Might change zoom factor S according to system loading ₂For example, if system load is low and have the effective identifier of minority, then the likelihood of system mistake ground Resources allocation is little.In this case, may use the low valve that detects.Along with system load increases, can increase and detect valve to reduce the ratio of incorrect decoded events.

Fig. 9 shows the block diagram of the embodiment of the user terminal 120x in access point 110x and the system 100.For this embodiment, each is equipped with a plurality of antennas access point 110x and user terminal 120x.Usually, access point and user terminal each all can equip the transmit/receive antenna of any number.

On up link, at user terminal 120x, TX data processor 310 is from data source 308 and other Data Receiving and the communication data (for example, CH1 and CH2 message) of handling self-controller 360, so that multiplexed data and pilot frequency code element to be provided, as above described for Fig. 3 A.TX spatial processor 320 can be carried out spatial manipulation and think that each antenna provides a string transmission code element on pilot tone and data symbols.Each modulator 340 receives and handles the corresponding code element stream that sends, and so that corresponding uplink modulated signals to be provided, transmits this uplink modulated signals from relevant antenna 350 then.

At access point 110x, T antenna 408a receives the uplink modulated signals that transmits to 408t from user terminal, and each day the alignment respective receiver 410 provide received signal.Each receiver 410 is adjusted received signal, and the signal of a step digitlization through adjusting of going forward side by side is to provide sampling.Detector/data demodulator 420 is carried out then and is handled to detect CH1 and CH2 message, as mentioned above.RX data processor 450 is handled the code element of recovering, with traffic data (providing to the data sink 452 that is used for memory) that decoding is provided and recover CH1 and CH2 message (provide further handle to controller 460).

The processing that is used for down link may be same as or be different from the processing that is used for up link.Handle (for example: encode, interweave and modulate) and can handle from data source 468 and the signaling of coming the data of self-controller 460 (as, response message) by TX data processor 470 by ground, TX spatial processor 480 spaces.Transmission code element from TX spatial processor 480 is handled T the downlink modulated signal that transmits to 408t via antenna 408a to produce by modulator 410a then to 410t.

At user terminal 120x, downlink modulated signal is received by antenna 350, is received by receiver 340 and adjusts and digitlizations, and complementally handled in the mode of the processing carried out at access point by RX spatial processor 370 and RX data processor 380.The data of the decoding of down link are provided for data sink 382 and are provided for storage and/or offer controller 360 further handling being used to.

Controller 360 and 460 is controlled at the operation of each processing unit at user terminal and access point place respectively.Memory cell 362 and 462 stores data and the program code that is used for controller 360 and 460 respectively.

Detector, demodulator and the receiver unit specific embodiment of correlation and judgement-guidance have been described for specific PDU form for clarity.For these detectors various other embodiment and to use also be possible, and this is within the scope of the invention.For example, correlation detector may be used to the channel transmitted of time bias, and the detector of judgement-guidance can be used to the channel transmitted of not free compensation.

Can in frequency domain (shown in Fig. 8 B) or time domain (shown in Fig. 8 C), realize the detector of judgement-guidance.In addition, the detector of judgement-guidance may be used to various PDU forms.For example, the detector of judgement-guidance may be used to such PDU form, wherein data and pilot tone are sub-band multiplexed (as above described for CH2 PDU), and data and pilot tone are time division multiplexings (TDM) (as above described for CH1 PDU) or the like.Can or not use the detector of judgement-guidance with pilot tone with pilot tone.Usually, the detector of judgement-guidance uses frequency domain to receive the data sampling of data symbols or time domain reconstruction to detect transfer of data in received signal.When unavailable CRC or other error detection mechanism during, can advantageously use this detector with the detect-message mistake.

The use adaptive threshold can provide the detection performance of robust in a plurality of operation schemes, for example in the frequency band for the no licence that has various interference sources.Can thresholding be set according to specific statistic for the transmission that will detect.The energy that this statistic can relate to useful signal adds interference in noise and the transmission or other parameter.

Shuo Ming detector here, demodulator and receiver can be used to various types of transfer channels.For example, these unit may be used to the Random Access Channel of different types, for example describe in detail in above-mentioned U.S. patent application 60/432,440 and U.S. Provisional Patent Application 60/421,309.

Shuo Ming detector here, demodulator and receiver can be used to the communication system that various wireless multi-paths insert.Such system is the wireless multiple access mimo system that illustrates in above-mentioned U.S. Provisional Patent Application 60/421,309.Generally speaking, these systems may or may not use OFDM, maybe can use other multi carrier modulation scheme to replace OFDM, and can or may not utilize MIMO.

Shuo Ming detector here, demodulator and receiver can be realized by variety of way.For example, can be at hardware, software or these unit of realization in their combination.Realize for hardware, one or more application-specific integrated circuit (ASIC) (ASIC) of the function of explanation here, digital signal processor (DSP), digital signal processing appts (DSPD) can be designed to carry out, programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, other electronic unit, or realize detector and receiver with their combination.

Realize for software, can with carry out described here functional module (as, process, function or the like) realize detector, the signal processing of demodulator and receiver.Software code can be kept at memory cell (as, the memory cell 362 and 462 among Fig. 9) and be carried out by processor (as controller 360 and 460).Can in processor or outside processor, realize memory cell, and realize under the memory cell situation beyond the processor that it can communicate to connect processor via the various devices that prior art is known the sixth of the twelve Earthly Branches.

Provide the explanation of the front of disclosed embodiment to build or use the present invention to allow any those skilled in the art.The technical staff is easy to these embodiment are carried out various modifications, and the general principle of definition here can be applicable to not deviate from other embodiment of the spirit or scope of the present invention.Therefore, the present invention embodiment of being not limited only to here show but meet according to the scope of the maximum of disclosed principle and novel features here.

Claims (24)

1. the receiver unit in the wireless communication system comprises:

One demodulator is used to handle the data symbols that received so that the code element of recovery to be provided;

First data processor is used to handle the code element of described recovery so that the data of decoding to be provided;

Second data processor is used to handle the data of described decoding so that the code element of modulation again to be provided; And

One detector is used to handle the data symbols of described reception and the code element of described modulation is again exported so that a detector to be provided.

2. receiver unit according to claim 1, the wherein said data symbols that receives are to be used to be assumed to be the transfer of data that received, and whether the transmission of wherein said detector output designation data is considered to receive.

3. according to the receiver unit of claim described 2, further comprise:

One threshold computation unit is used for determining a thresholding that is used for transfer of data, and

Wherein said detector is used for providing a tolerance according to the data symbols of described data symbols that has received and modulation again, and wherein determines described detector output according to described tolerance and thresholding.

4. receiver unit according to claim 3, wherein threshold computation unit is used for determining thresholding according to the signal that is used for a plurality of receptions of a plurality of antennas, and wherein detector is used for determining described tolerance according to the signal of a plurality of receptions.

5. receiver unit according to claim 1, wherein detector is further used for handling the pilot frequency code element that received so that detector output to be provided.

6. receiver unit according to claim 5, wherein data symbols sends on data subbands, and pilot frequency code element sends on pilot subband, and wherein data subbands and pilot subband are multiplexed.

7. receiver unit according to claim 6, wherein data subbands and pilot subband interweave, and make the two ends of each data subbands all be joined by pilot subband.

8. receiver unit according to claim 1, wherein detector is used for carrying out the coherent detection of time domain.

9. receiver unit according to claim 8, wherein obtain the code element that has received, and wherein detector is used at input sample and carries out relevant between according to the reconstructed sample that modulated symbol obtains again according to the input sample that is used to be assumed to be the transfer of data that has received.

10. receiver unit according to claim 8, wherein obtain the code element that has received, and wherein detector is used at input sample with according to modulated symbol again and be used for carrying out between the reconstructed sample that the pilot frequency code element of transfer of data obtains relevant according to the input sample that is used to be assumed to be the transfer of data that has received.

11. receiver unit according to claim 1, wherein detector is used for carrying out the differential detection of frequency domain.

12. receiver unit according to claim 5, wherein detector is used for:

The corresponding code element of modulation again of each data symbols that has received and one is multiplied each other, so that a demodulated data symbol to be provided,

Each pilot frequency code element that has received and a corresponding known symbols are multiplied each other, so that the pilot frequency code element of a demodulation to be provided,

Between the pilot frequency code element of demodulated data symbol and demodulation, carry out dot product, and

The result of dot-product is added up.

13. receiver unit according to claim 2, wherein transfer of data is used for the Random Access Channel at wireless communication system.

14. receiver unit according to claim 1, wherein this wireless communication system uses multi-carrier modulation.

15. receiver unit according to claim 1, wherein this wireless communication system uses Orthodoxy Frequency Division Multiplex (OFDM).

16. the receiver unit in the wireless communication system comprises:

One processor is used to handle the data symbols that has received that is used to be assumed to be the transfer of data that has received, and the code element of modulation again is provided, and these code elements of modulating again are the estimations to the data symbols that sends; And

One detector, the code element that is used to handle the data symbols of reception and modulation again is to provide a detector output, and whether this output designation data transmission is considered to receive.

17. receiver unit according to claim 16, wherein processor is used for data symbols that demodulation received so that the code element of recovery to be provided, the code element that decoding recovers is providing decoded code element, and the decoded code element of recompile is to provide the code element of modulation again.

18. receiver unit according to claim 16, wherein processor is further used for handling pilot frequency code element of reception and the corresponding known pilot symbols that is used for transfer of data, so that detector output to be provided.

19. a method that detects the transfer of data in the wireless multiple access communication system comprises:

First handles, and handles the data symbols that has received that is used to be assumed to be the transfer of data that has received, and so that the code element of modulation again to be provided, these code elements of modulating again are the estimations to the data symbols that sends; And

Second handles, and the code element of handling described data symbols that has received and modulation again is to provide a detector output, and whether this output designation data transmission is considered to receive.

20. method according to claim 19, wherein said first processing comprises:

The data symbols that demodulation has received to be providing the code element of recovery,

The code element that decoding recovers to be providing decoded data, and

The decoded code element of recompile is to provide the code element of modulation again.

21. method according to claim 19 further comprises:

The thresholding of the transfer of data that is identified for supposing, and wherein further determine detector output according to described thresholding.

22. method according to claim 21, wherein second processing comprises:

Code element according to data symbols that has received and modulation is again determined a tolerance, and

To measure with thresholding and compare, wherein this detector output is based on this comparison.

23. an equipment that is used in the wireless multiple access communication system comprises:

Be used to handle the data symbols that has received that is used to be assumed to be the transfer of data that has received to provide as device to the modulated symbol again of the estimation that sends data symbols; And

Be used to handle the device that data symbols that has received and the code element of modulating are again exported with the detector that provides a designation data transmission whether to be considered to receive.

24. equipment according to claim 23 further comprises:

Be used for the device of demodulation data accepted code element with code element that recovery is provided,

Be used to decode the code element recovered so that the device of decoded data to be provided, and

Be used for the decoded data of recompile so that the device of the code element of modulation again to be provided.

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