CN100568748C - The method and apparatus that is used for noise testing - Google Patents

Abstract

Noise testing is to carry out in the single symbol period segment of the longest orthogonal code symbol.Processor controls (520) identifies the unappropriated sign indicating number of a spreading factor less than the longest spreading factor of system.Despreader (512) is measured symbol energy based on unappropriated sign indicating number, and noise estimator (512) produces Noise Estimation based on the symbol energy that records.Subscriber station is to use similar techniques, to finish channel estimating in the cycle of a symbol period segment of long bandspread factor code.

Description

The method and apparatus that is used for noise testing

The cross reference of related application

The application required to submit " improved noise and the channel estimating of utilizing low spreading factors " by name, the U.S. Provisional Application No. of patent application serial numbers 60/424,474 on November 6th, 2002.

Technical field

The present invention puts it briefly and relates to radio communication, relates to the improved Noise Estimation in the wireless communication system specifically.

Background technology

Wireless communication field comprises a lot of wireless applications, as voice communication, and paging, Packet data service, and IP phone.A kind of challenge that these services are drawn is for the big different requirement of capacity, service quality, stand-by period, data transfer rate in different business.Various air interfaces grow up, and to utilize different wireless communication technology (as frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA)) these business are carried out combination.

Have the combination that does not require on the same group professional in order to adapt to, communication standard (as the CDMA2000 that is suggested and W-CDMA) has offered some clarification on the use of the orthogonal code of different length in the down channel from the wireless base station to the subscriber station.Some standards have also offered some clarification on the signal that the orthogonal code that is used for the elongated degree of different channels is launched different up channels (direction from the subscriber station to the wireless base station).For example, three types downstream signal may be launched in a wireless base station: pilot tone, voice, grouped data, and utilize the orthogonal code symbol of different length to come channelizing or " covering " various dissimilar signals.The length of orthogonal code symbol typically is described as many " chip ", and each chip is meant the binary system part of the minimum that transmits.In a spread spectrum system, the binary system chip sequence of each bit of information and pre-set every bit number of chips multiplies each other.Multiply by independent binary message bit by orthogonal code symbol, effectively the information bit of all chips in " expansion " symbol.Therefore, chip lengths or every bit number of chips often are known as " spreading factor " of emission information signal.

Another aspect of existing spread spectrum system is between the different user station and the frequency band between the different base station is shared.That is to say that the adjacent base station in spread spectrum system is with their downstream signal of identical band transmission.Because shared (also the crying " multiplexing ") of frequency band, the downstream signal of base station can disturb the downstream signal of adjacent base station devastatingly.No matter be from supported subscriber station number or the aspect of possible maximum information throughput is weighed from the down link, this interference all will reduce the capacity of adjacent base station.Still can allow signal to be received and the minimum of decoding by subscriber station is correct by using power control techniques that the transmitting power of all signals is reduced to, can improve the capacity of this system.The validity of power control is to a great extent by the accuracy decision of the noise testing of subscriber station and base station.Therefore, in the art, need a kind of means that the maximization noise measurement accuracy of using the variable bandspread factor system is provided.

Summary of the invention

Embodiment disclosed herein carries out noise testing and becomes possibility by making in the single symbol period segment of the longest orthogonal code symbol, reach demand proposed above.First aspect, the subscriber station of wireless system determines when on each channel of preceding two channels of the spreading factor expansion the longest with this wireless system and is sending information, also to determine to use the most ensuing two channels unoccupied (not being used to transmit data) of long spreading factor, and on the cycle of a symbol period segment of the longest spreading factor code sign, carry out Noise Estimation.Second aspect, subscriber station are determined the untapped channel of a relevant short spreading factor code sign, and carry out Noise Estimation in the symbol period of short bandspread factor code.The third aspect, subscriber station are used similar technology, so that carry out channel estimating in the cycle of a symbol period segment of long bandspread factor code.

Subscriber station may identify independently and not use channel.As selection, also may provide the sign of not using channel to subscriber station by the base station.

Description of drawings

Present invention is described with reference to accompanying drawing.In the accompanying drawings, same label is represented identical or intimate part.

Fig. 1 is the wireless communication system of example;

Fig. 2 is the example codes tree with a untapped short spreading factor channel;

Fig. 3 is based on the exemplary method that utilizes first group the longest bandspread factor code with common father's sign indicating number to measure noise;

Fig. 4 is based on the exemplary method that unappropriated short bandspread factor code is measured noise;

Fig. 5 utilizes short bandspread factor code to measure the example subscriber station of noise;

Fig. 6 provides and can use the example base station equipment that short bandspread factor code carries out the transmission signals of Noise Estimation.

Embodiment

Fig. 1 is an exemplary wireless communication system with an independent base station, comprises the subscriber station that has antenna 104 102 that communicates with the base station 112 that has antenna 114.Base station 112 or subscriber station 102 may use many antennas under the situation of the embodiment that does not depart from this paper and set forth.Subscriber station 102 is given by down channel 124 emission wireless signals in base station 112.Subscriber station 102 sends wireless signal to base station 112 by up channel 122.Base station 112 utilizes different subchannels to send multiple signal by down channel 124.In one exemplary embodiment, different downlink sub-channels can be distinguished by orthogonal code.That is to say, expand by this data bit being multiply by in the 112 employed sign indicating numbers of base station certain unique orthogonal code symbol in a certain specific data (data bit) of giving every bit that channel transmits.In one exemplary embodiment, subscriber station 102 utilizes the knowledge of the orthogonal code symbol that different subchannels are encoded and the knowledge which subchannel just is being used for transmitting data, comes the noise that down channel 124 receives is measured.

As used herein, term " noise " comprises the interference of thermal noise, and the interference that is caused by the signal of other signal sources emission.As used herein, subscriber station may be that move or fixing, and may communicate with one or more base stations.Subscriber station can be any in a variety of devices furtherly, including, but not limited to: the PC card, the CF card, external or internal modem, radio telephone may also comprise telephone or modulator-demodulator.

Be easy to realize technology that noise testing is improved the figure illustrates exemplary code tree with reference to Fig. 2, this code tree shows the distribution of the orthogonal code symbol of different subchannels.Exemplary embodiment shown in Figure 2 is according to the described subchannel allocating method of W-CDMA standard, but applicable to any wireless signal that different subchannels is used the different length spreading code.Code tree 220 has as shown in Figure 2 illustrated a kind of systems approach of distributing the orthogonal code symbol of different chip lengths for different subchannels.Under the situation that each data bit and complete code sign multiply each other, the length of code sign just equals the spreading factor of subchannel in the chip.

In Fig. 2, each " father " orthogonal code with first symbol lengths can be used for obtaining two " son " orthogonal codes with this symbol lengths of twice.(X Y) represents the rank of orthogonal code, and wherein X is the number of chip in the orthogonal code, and Y is the sequence number that is in other yard of this grade from the top to the bottom with label C.The value of X also can be regarded the spreading factor (SF) of correspondence code as.When father's orthogonal code obtains two sub-orthogonal codes, first in two sign indicating numbers is father's sign indicating number of twice of repetition, and second in two sign indicating numbers is the negate that father's sign indicating number back is added this yard.So two chip code C (2,0) with chip sequence (+,+) split into two four chip child codes, C (4,0)=(+,+,+,+) and C (4,1)=(+,+,-,-).Similar, two chip code C (2,1) with chip sequence (+,-) split into two four chip child codes, C (4,2)=(+,-,+,-) and C (4,3)=(+,-,-,+).Structure according to said method, the sign indicating number in the code tree on all " leaf " nodes can guarantee the leaf segment point coding quadrature with other, even the sign indicating number on some leaf nodes is than other leaf segment point codings longer (comprise more many chip).

Though code tree 220 the longest branches are presented at the top, (X, Y) the Y value in is less, does not get rid of and uses the code tree with the long branch of extending than the branch of bottom to the right for the label C of just the longest sign indicating number.For example, C in the code tree (4,0) and two branches of C (4,3) may extend to the leaf segment point coding of 256 chips always, and while C (4,1) and C (4,2) are as the leaf segment point coding.

As mentioned above, exemplary channel allocation shown in Figure 2 is based on the described subchannel allocating method of W-CDMA standard.Therefore, expand the pilot subchannel that is called as Common Pilot Channel (CPICH) with the sign indicating number of the C (256,0) in the code tree branch 202, and the C in the code tree branch 204 (256,1) sign indicating number is used to expand Primary Common Control Physical Channel (P-CCPCH).Sign indicating number the longest in code tree 220 has 256 chips.Therefore, 256 chips just are called as the longest spreading factor of code tree 220, and any have the sign indicating number of 256 chips all to be known as the longest bandspread factor code in code tree 220.In the W-CDMA code tree, CPICH and P-CCPCH are the longest bandspread factor codes.

As mentioned above, according to the requirement of the business relevant with channel, the spread spectrum system of expection uses different spreading factors for different channels.For example, in W-CDMA, be the pilot channel symbols covering pilot signal of 256 chips with length, be the channel symbol covering voice signal of 128 chips with length, and may be the channel symbol covering packet data signals of 64 chips with length.Therefore, the spreading factor of pilot tone, voice, Packet Data Channel is respectively 256,128, and 64.In addition, the voice signal of some low-vocoder-rate also can cover with the channel symbol of 256 chips.

Do not knowing which bar channel just is being used for transmitting under the situation of information signal, may can only carry out noise testing by the longest spreading factor.That is to say that in the W-CDMA system that uses code tree shown in Figure 2, if a subscriber station does not know which bar channel also is not assigned with, subscriber station just can only carry out noise testing with the longest spreading factor of 256 chips so.

Yet, know that at subscriber station one or more has under the situation of channel of shorter spreading factor, might improve noise testing.In one exemplary embodiment, subscriber station determines that the channel that a spreading factor is 128 chips is not used, thereby carries out noise testing in 128 chip period.The result can obtain twice 128 chip noise testings in each 256 chip period.For example, if subscriber station is determined the C (128 in the code tree branch 206,1) sign indicating number is not used to from base station transmission signal, subscriber station just can be at the CPICH C (256 in the code tree branch 202,0) or the P-CCPCH sign indicating number C (256 in the code tree branch 204,1) in each 256 chip period, generates the noise testing of twice 128 chips.

Do not using under the situation that channel can be identified, the frequency of Noise Estimation just can not be higher than per 256 chips once.Such Noise Estimation is unfavorable, because need the longer time to go to generate, and compared with using the Noise Estimation that generates, averages then than the short period, its ratio of precision is lower.In the absence of the sign indicating number of in the code tree known to the subscriber station 220, selecting unoccupied (be used for transmitting data), can generate improved Noise Estimation.

In order to think that a sign indicating number is unappropriated, all subcodes of this yard all must be unappropriated.For example, for C (32, the 31) sign indicating number 218 that makes 32 bits is considered to unoccupied, the subcode C of 64 bits (64,62) 210 and C (64,63) 216 must be unoccupied.Unoccupied for 216 yards of C (64,63) that make 64 bits, the subcode C of 128 bits (128,126) 212 and C (128,127) 214 must be unoccupied.If a sign indicating number corresponding codes channel is not used in transmission, perhaps delivering power is 0, and this sign indicating number can be considered to unappropriated so.

Shown in Figure 3 is to utilize the knowledge of unoccupied encoding channel to carry out the illustrative methods of improved Noise Estimation.In step 304, subscriber station is determined preceding four operating positions of long bandspread factor code.The method that subscriber station can be made this judgement is included in downlink message of pointing out these yards operating position of step 302 reception.As selection, subscriber station also can come the information measurement that receives to determine that independently which channel relevant with the longest bandspread factor code just is being used to transmit signal.

In order to make improved Noise Estimation become possibility, these four bandspread factor codes the longest must belong to same father's sign indicating number.For example, subscriber station has a priori, is exactly first the longest bandspread factor code, and C (256,0) 202 is used for transmitting complete 1 pilot channel (CPICH), and second bandspread factor code the longest, C (256,1) 204 is used for transmitting the P-CCPCH data.In step 302, subscriber station may receive an all unappropriated downlink message of remaining two subcodes that indicates father's sign indicating number C (64,0) 208.Specifically, the downlink message that receives in step 302 indicates C (256,2) and whether C (256,3) sign indicating number is all unoccupied, and perhaps whether father's sign indicating number C (128,1) 206 is unoccupied.In one exemplary embodiment, the downlink message of step 302 reception is a single-bit.Downlink message can be received from the base station by dedicated channel, broadcast channel or Multicast Channel.

When having half unoccupied in subscriber station is determined four subcodes of father's sign indicating number, subscriber station can produce twice Noise Estimation in per two code symbol period of father's sign indicating number.Specifically, in step 306, the signal that subscriber station utilizes the despreading of father's sign indicating number to receive provides short SF despread signal.Then, in step 308, short SF despread signal deposits buffer memory in first father's code symbol period.In step 310, short SF despread signal is deposited in buffer memory again in second father's code symbol period.In step 312, the difference that is deposited in the value of buffer memory and deposited in the value of buffer memory in first father's code symbol period in second father's code symbol period is determined.Constitute the Noise Estimation of receive channel in the difference of step 312 foundation.This difference can be determined by deduct a primary class value from a secondary class value.

Must be pointed out that must be corresponding to such father's code symbol period corresponding to the signal of the father's code symbol period that may subtract each other: the data that known two occupied channels transmit in these cycles be identical.For example, determine under C (256,2) and all unappropriated situation of C (256,3) that subscriber station knows that again the chip value of first 64 chip period transmission is identical with the chip value that second 64 chip period transmits at subscriber station.Specifically, first 64 chip of CPICH sign indicating number is identical with second 64 chip of CPICH sign indicating number, and first 64 chip of P-CCPCH sign indicating number is identical with second 64 chip of P-CCPCH sign indicating number.Therefore, any difference of the energy value of the chip of first that receives 64 chip period and second 64 chip period all just comes from noise.The difference of the energy value of the 3rd 64 chip period that receive similarly, and the chip of the 4th 64 chip period all just comes from noise.Therefore, when subscriber station knew that C (256,2) and C (256,3) sign indicating number is unoccupied, subscriber station can preceding two 64 chip period and latter two 64 chip period during each 256 chip code symbol respectively generate a Noise Estimation.Be these two Noise Estimation that per 128 chips need generate, can directly use or sue for peace to be averaged the Noise Estimation that generates reliable receive channel.

In one exemplary embodiment, for example, use quick Hadamard transformation, poor between the interference energy value of determining to receive according to 64 chip symbol-symbol (symbol-by-symbol).In one exemplary embodiment, each 256 chip code symbol period is divided into two 128 continuous chip code symbol period.Each of these two 128 chip code symbol period is divided into two 64 continuous chip code symbol period again.First Noise Estimation of first 128 chip code symbol period is provided by the difference of measuring first 64 chip period and second 64 chip period symbol energy.First Noise Estimation of second 128 chip code symbol period is provided by the difference of measuring the 3rd 64 chip period and the 4th 64 chip period symbol energies.64 chip father sign indicating numbers of CPICH in W-CDMA and P-CCPCH channel are under the situation of C (64,0) all-ones 208, and the measurement of 64 chip symbol energy can be practically multiplied each other the sample that receives and C (64,0) sign indicating number 208 and generated.Multiplying each other like this there is no need, and can not change the sample that receives because the sample that receives be multiply by all-ones.

Subscriber station also can use C (128,1) sign indicating number 206 to carry out the channel estimating of improved wireless channel.Specifically, the CPICH channel is the pilot channel that never is used for transmitting data in W-CDMA.The CPICH channel is used as the phase place of the channel estimating that the coherent demodulation that makes downstream signal can realize and the reference of amplitude.Be used to transmit under the data conditions at C (128,1) sign indicating number 206, the channel estimating of carrying out with CPICH sign indicating number 202 can only generate once in the CPICH of each the 256 chip code sign signal period.Yet, know under the situation that the P-CCPCH channel transmits with 90% duty factor as mentioned above at subscriber station, during the P-CCPCH sign indicating number is unappropriated, use father's sign indicating number C (128 so, 0) sign indicating number just can per 128 chip code symbol period generate a channel estimating as pilot code.Subscriber station just can generate twice channel estimating in one 256 chip code symbol period.

In addition, also know under C (128,1) the sign indicating number 206 unappropriated situations at subscriber station, during the P-CCPCH sign indicating number is unappropriated, can be in each 64 chip code symbol period generation channel estimating.Specifically, be that father's sign indicating number C (64,0) 208 can be used as the pilot code of 64 chips in that 10% time of the unique occupied subcode of father's sign indicating number C (64,0) 208 at the CPICH sign indicating number.Per 64 chip code symbol period of subscriber station generate a channel estimating, and per in other words 256 chip code symbol period generate four channel estimating.In one exemplary embodiment, subscriber station carries out infinite impulse response or finite impulse response filtering to these 64 chip channel estimating, is actually used in the channel estimating of the coherent demodulation of residue channel with generation.As selection, subscriber station can not carry out filtering yet and directly uses channel estimating.

Shown in Figure 4 is another kind ofly knows the method that has a spreading factor to measure noise under than the short situation of not using sign indicating number of the spreading factor of the longest bandspread factor code the user.In step 404, subscriber station identifies this untapped sign indicating number.The method of the untapped sign indicating number of subscriber station identification is included in the downlink message that step 402 receives a untapped sign indicating number of identification.As selection, subscriber station also can be measured to received signal to identify untapped sign indicating number independently.

In case subscriber station identifies a untapped sign indicating number, subscriber station just can be in Noise Estimation of generation in each and the corresponding symbol period of untapped short SF sign indicating number.In step 406, the signal that subscriber station uses this untapped sign indicating number despreading to receive, thus obtain a short SF despread signal.Then, in step 408, subscriber station is estimated from short SF despread signal generted noise.

For example, if untapped sign indicating number has 64 spreading factor, so that the code sign length of untapped sign indicating number is 64 chips, so in step 408, subscriber station can generate a new Noise Estimation by per 64 chips.Perhaps subscriber station also can generate four independent Noise Estimation by per 256 chips.These four Noise Estimation can be averaged together also and can use respectively.As selection, Noise Estimation also can be transfused to wireless impulse response (IIR) filter or finite impulse response (IIR) filter.In per 256 chip period four 64 chips are estimated to average an instantiation can regarding the FIR filter as.

Because subscriber station is known the untapped sign indicating number that identifies and is not used for transmitting any signal, and because subscriber station is also known all other sign indicating number all and should untapped yard quadrature, so the difference of the some and next chip energy value that receives from untapped code symbol period is just caused by noise.In the exemplary embodiment of a unappropriated sign indicating number of use 64 chips, subscriber station is determined the signal energy of each 64 chip period, determines the difference of the symbol energy values of this symbol energy values and previous 64 chip period then.In one exemplary embodiment, utilize quick Hadamard transformation (FHT) to determine symbol energy values.Subscriber station can directly use short SF Noise Estimation, also can will lack the SF Noise Estimation by infinite impulse response (IIR) filter or finite impulse response (FIR) filter filtering earlier.The example of a FIR filter is exactly to average the code symbol period to each 256 chip to generate one 256 chip Noise Estimation for four continuous Noise Estimation.

In the W-CDMA system of suggestion, the CPICH channel is not used to carry data message.Specifically, the CPICH channel is a total pilot channel that keeps steady state value.At the CPICH channel is under the situation of all-ones C (256,0) 202, the CPICH channel represent one can be by the Constant Direct Current signal of the effective demodulation of any orthogonal code.The suggestion the W-CDMA system be the discontinuous transmission of P-CCPCH channel on the other hand.Specifically, the P-CCPCH channel transmits with 90% duty factor, so that corresponding P-CCPCH sign indicating number 204 is unoccupied in the time of per ten 256 chip code symbol period.Thereby the phase place of these circulations of subscriber station can determining simply can identify in ten 256 chip code symbol period P-CCPCH sign indicating number 204 unappropriated that.Knowing under the also unappropriated situation of remaining 128 chip code 206, just allowing subscriber station that father's sign indicating number C (64,0) 208 of 64 chips is treated as being that essence is unappropriated.Therefore, in one exemplary embodiment, when occupied subscriber station can be according to P-CCPCH sign indicating number 204 conversion between Fig. 3 and Noise Estimation technology shown in Figure 4.Specifically, in ten 256 chip code symbol period nine, the Noise Estimation that subscriber station execution graph 3 is described.Yet during per ten 256 chip code symbol period, subscriber station is that in three transformations between 64 chip segments in 256 chip code symbol period each generates a Noise Estimation.

During per ten 256 chip code symbol period, when the P-CCPCH channel does not transmit, 256 chip code symbol period are divided into 4 64 chip period in succession, in step 406, subscriber station is measured each interfering energy of four 64 chip period, and generates Noise Estimation in step 408 by determining the difference of interfering energy between measuring.First Noise Estimation is to be produced by the symbol energy difference of first and second 64 chip period, second Noise Estimation is that the symbol energy difference by second and the 3rd 64 chip period produces, and the 3rd Noise Estimation is that the symbol energy difference by third and fourth 64 chip period produces.In another alternate embodiments, subscriber station can generate the noise testing more than 3 by the method for determining the difference between non-conterminous 64 chip period in the tenth 256 chip code symbol period.For example, the 4th Noise Estimation can generate by the difference of determining the interferometry during first and the 4th 64 chip segment in 256 chip code symbol period.

As selection, under the situation of another the unoccupied sign indicating number beyond subscriber station is known C (64,0) code tree branch, subscriber station can also use a plurality of unoccupied sign indicating numbers to carry out Noise Estimation and combination Noise Estimation simultaneously.For example, at known C (128,1) sign indicating number 206 and C (64,62) under the sign indicating number 210 all unappropriated situations, P-CCPCH sign indicating number 204 unappropriated those one-periods in per 10 chip code symbol period, subscriber station can make up the Noise Estimation of utilizing C (64,0) 208 and C (64,62) 210 code signs to generate.In addition, the Noise Estimation of using the code sign of different chip lengths to generate also can be combined and produce more accurate combination Noise Estimation.For example, under the known C of subscriber station (64,62) 210 and C (128,126) 212 all unappropriated situations, subscriber station can utilize these two unappropriated sign indicating number generted noises to estimate, makes up the combination Noise Estimation that Noise Estimation forms per 128 chips or per 256 chips then.

Shown in Figure 5 is an exemplary apparatus of subscriber station 102, and it is configured to have first group of bandspread factor code the longest of public father's sign indicating number to measure noise (as the relevant discussion of Fig. 3) based on utilization.Receive wireless signal by antenna 104.As mentioned above, subscriber station 102 may use many strip antennas, but does not depart from embodiment described herein.Before being sampled by sampler 506, the gain of signal is regulated by automatic gain control (AGC) 504.AGC 504 may comprise also that the low-converter of a numeral or simulation is down-converted to intermediate frequency or base band frequency with the signal that receives.Then sampled signal is offered descrambler 508, obtain descramble signal thereby sampled signal be multiply by the scrambler that scrambling code generator 518 generates 508 li of descrambler.

Sampler 506 may be carried out the real number sampling, generates single stream of digital samples.As selection, sampler 506 also can be carried out complex sampling, and a complex sampling signal flow with in-phase signal part and quadrature phase signal part is provided.Sampler 506 may be sampled with the sampling rate of sampled point of every chip (being commonly referred to as " chip-x-1 ") to the received signal, also may use the higher sampling rate as every chip 4 sampled points (being commonly referred to as " chip-x-4 ").

Scrambling code generator 518 may generate the real scrambler that the single numerical value stream of usefulness is represented, perhaps also may generate the multiple scrambler of real part and imaginary part.One of them is that descrambler 508 uses real multiplications to carry out the descrambling functions under the situation of unique real number in scrambler and sample flow.At scrambler and sample data stream all is under the situation of plural number, and 508 pairs of duplicate sample notebook data streams of descrambler and multiple scrambler carry out complex multiplication.The details of this complex multiplication is at U.S. Patent number 5,930, the 230[the230 patent] in describe.Subscriber station 102 also may use the pilot filter (not shown) to correct the intrinsic phase error of channel.The detailed example of real pilot filter is at U.S. Patent number 5,506, provides in 865, provides in 230 patents that the detailed example of multiple pilot filter is mentioned in front.

In one exemplary embodiment, the scrambler of scrambling code generator 518 generations is corresponding with the scrambler that single base station uses.In one exemplary embodiment, in order to make this signal of base station and next signal of base station quadrature or nearly orthogonal, each base station is carried out scramble with different scramblers to its all transmission.For example, some base station is carried out scramble with identical pseudo-code (PN) sequence of elapsed time skew to their transmission, thereby obtains nearly orthogonal.The base station can be used the PN sequence and be duplicated (for example, per 26.7 milliseconds) or clocklike to block at interval or to restart PN sequence (for example, a message frame after initial per 10 milliseconds) up to it.The application of other kind scrambler also is foreseeable.

The descramble signal of descrambler 508 outputs multiply by short spreading factor (short SF) sign indicating number in short sf despreader 512.The control signal that the short SF sign indicating number that short SF despreader 512 uses is sent by processor controls 520 is determined.For example, receive CPICH and P-CCPCH signal simultaneously, but under ensuing 128 chip code, the 206 known unappropriated situations, the sample signal of 208 pairs of receptions of short SF despreader 512 usefulness C (64,0) sign indicating number is with 64 chip increment despreadings at subscriber station.This area personage generally acknowledge to utilize the all-ones as C (64,0) to carry out despreading and calculates without any need for multiplication reality and sign indicating number, finishes and can only deposit the chip energy value in buffer memory.In one exemplary embodiment, lack SF despreader 512 and deposit the buffer memory (not shown) in what preceding 64 chip one chips of each 128 chip code symbol period connect a chip.In the cycle of second 64 chip of each 128 chip code symbol period, short SF despreader 512 is determined the difference of the chip energy of the chip energy of each 64 chip period and previous 64 chip period corresponding with it, and each 64 chip energy difference values is exported to noise estimator 516.Noise estimator 516 utilizes these chip energy difference values to determine the Noise Estimation of each 128 chip code symbol period.As selection, short SF despreader 512 also can provide the interference measure of simple each 64 complete chip code symbol period, and a pair of interference measure of noise estimator 516 usefulness is Noise Estimation of each 128 chip code symbol period generation then.Noise estimator 516 output noises are estimated to processor controls 520.Like this, in one exemplary embodiment, customer station equipment 102 is according to the described method operation of Fig. 3.

As selection, customer station equipment 102 also can be according to the described method operation of Fig. 4.For example, determine one under the unappropriated situation of short SF sign indicating number outside the C of code tree branch (64,0) 208 at subscriber station, subscriber station can generate a new Noise Estimation after each code symbol period of this unappropriated sign indicating number.In this case, signal of processor controls 520 outputs determines to be used for the unappropriated short bandspread factor code of noise testing for short SF despreader 512.In one exemplary embodiment, lacking SF despreader 512 utilizes one to connect output energy difference in a chip ground with unappropriated short bandspread factor code with the buffer memory (not shown) of length and from a unappropriated code symbol period to the unappropriated code symbol period of the next one to noise estimator 516 1 chips.As selection, short SF despreader 512 also can be created on each corresponding to the simple interference measure in the code symbol period of unappropriated code sign.In one exemplary embodiment, lacking SF despreader 512 utilizes the quick Hadamard transformation (FHT) of a unoccupied code sign to produce simple interference measure.In this way, noise estimator 516 just can generate a new Noise Estimation after corresponding to each code symbol period of unappropriated sign indicating number.

As mentioned above, know C (128 at subscriber station 102,1) coding 206 is unoccupied, and the P-CCPCH channel only has under the situation of transmission in 9/10ths 256 chip code symbol period, and processor controls 520 reconfigures short SF despreader 512 and noise estimator 516 for the noise testing of optimizing each 256 chip code symbol period.Specifically, processor controls 520 is provided with short SF despreader 512 and noise estimator 516, and in 90% time that is used to transmit at the P-CCPCH channel, per 128 chips generate a Noise Estimation.In 10% time that the P-CCPCH channel is not used to transmit, processor controls 520 reconfigures short SF despreader 512 and noise estimator 516, generates a Noise Estimation with per 64 chips.

Above also discussed how to make subscriber station can according to P-CCPCH204 and 206 yards all unappropriated information of C (128,1) at least the one-period in per ten 256 chip period produce improved channel estimating.In one exemplary embodiment, the output of descrambler 508 is provided for channel estimator 522.Channel estimator 522 generates a channel estimating on each code symbol period of C (64,0) sign indicating number 208.Each channel estimating all comprises amplitude and phase information, improves the performance of the coherent demodulation of each downlink channel signals with these information.Channel estimator 522 can carry out filtering by the output to descrambler 508, for example uses IIR or FIR filter filtering to generate the estimation of each channel.In one exemplary embodiment, channel estimator 522 comprises that further additional secondary filter comes the channel estimating of 64 chips is carried out filtering.In one exemplary embodiment, these secondary filters can be IIR or FIR filter.An example of FIR filter is exactly that four 64 chip channel estimating in each 256 chip code symbol period are averaged, thereby the aggregate channel that forms per 256 chip code symbol period is estimated.

The identification of unappropriated sign indicating number can be finished by in several means any one.For example, the sign of one or more unoccupied sign indicating numbers can send subscriber station 102 to by a control channel in a signal.As mentioned above, only need indicate C (128,1) sign indicating number 206 in the base station whether under the unappropriated situation, this task can only be finished with a single information bit.For example, transmit " 1 " and represent C (128,1) sign indicating number 206 unoccupied, transmit " 0 " and represent that C (128,1) yards 206 is just occupied to be used for transmitting data.This single bit can be from the base station transmits by a control channel, and with 510 demodulation of control channel demodulator.In one exemplary embodiment, the output of descrambler 508 offers control channel demodulator 510, and this demodulator is separated single information bit and transferred to determine that its value is " 1 " or " 0 ", and decoded bits is exported to processor controls 520.Processor controls 520 is adjusted to the control signal of short sf despreader 512 and noise estimator 516 according to the value of information bit.

Control channel signals also may comprise the data that are used for indicating the unappropriated sign indicating number outside the C of code tree branch (64,0) 208.Control channel demodulator 510 demodulation control channel signals, and the data that will indicate unappropriated sign indicating number are exported to processor controls 520.Then, processor controls 520 control signal of adjusting to short sf despreader 512 and noise estimator 516 instructs them to utilize unappropriated sign indicating number generted noise to estimate.Noise estimator 516 output noises are estimated to processor controls 520.

As discussed above, the used control channel of signal that is carried out demodulation by control channel demodulator 510 may be a broadcast channel, and the dedicated channel of subscriber station 102 perhaps is used for to comprising that a plurality of subscriber stations of subscriber station 102 transmit the Multicast Channel of information.Subscriber station 102 is being arranged to can carry out (for example, different types of noise is as shown in Figure 3 and Figure 4 estimated) under the situation of polytype Noise Estimation, dissimilar unoccupied channel informations may be with dissimilar channel transmission.For example, the single-bit of indication C (128,1) sign indicating number 206 operating positions may transmit with broadcast channel, and another message that is used for discerning a different unappropriated sign indicating number may be with a dedicated channel transmission.

The different form that much is used to discern unappropriated sign indicating number here is foreseeable.In one exemplary embodiment, control channel is used for transmitting the sign of spreading factor and untapped sign indicating number.For example, (X Y) can use 8 bit values of a position mapping to discern to sign indicating number C, and 8 bits of this mapping comprise two bits that are used for discerning X, 6 bits that are used for discerning Y.Use such sign indicating number, dibit should enough be used for representing the code length of any from 16 to 128 chips or from 8 to 64 chips.6 bits should provide by any one index in 64 sign indicating numbers in the group of preceding dibit identification.As selection, use control channel bit still less also can discern this group coding, to pre-determine be in the short bandspread factor code that seldom uses one to discern one group.For example, the base station can comprise rule a: C (32,31) 218, and C (64,63) 216 and C (128,127) 214 always just distribute at last.In this several encoding any one can be with a dibit information representation.For example, " 00 " expression does not have a channel unoccupied, and " 01 " expression C (32,31) is unoccupied or the like.Also have a kind of possible selection, just be to use single predetermined short bandspread factor code, for example 64 chip C (64,1) sign indicating number (not shown) just can only be represented with single-bit.As selection, the sign indicating number that any other is predetermined take or the unoccupied state also can be represented with an independent bit specifically distributing to this signal.

As selection, equipment shown in Figure 5 can be used to identification and not use encoding channel and need not to receive this information from control channel.In one exemplary embodiment, subscriber station 102 utilizes equipment shown in Figure 5, and a part or all possible 64 chip code are carried out the energy threshold search.

Shown in Figure 6 is an exemplary base equipment that provides the short bandspread factor code of permission use to carry out the transmission signals of Noise Estimation.Unmodulated CPICH signal 602 is exported to an adder 618.In P-CCPCH channel modulator 628, modulate with 204 pairs of P-CCPCH signals 604 of P-CCPCH sign indicating number.Then, the gain that is exported to the P-CCPCH signal of 610 pairs of modulation of gain controller of the P-CCPCH signal of modulation is adjusted individually.In one exemplary embodiment, switch 612 is periodically opened the transmission of controlling the P-CCPCH channel, and for example with 90% duty factor, just channel transmitted in 90% time, and remaining 10% time does not transmit.In one exemplary embodiment, switch 612 disconnects the code symbol period of one 256 chip in the code symbol period of per ten 256 chips.

Data-signal 606 is exported to one or more data signal modulation devices 614, and these modulators use the code sign of distinct symbols length and different spreading factors that independent data-signal is modulated, and the data-signal of modulation is provided.Through after the modulation of modulator 614, each data-signal all passes through gain controller 610 quilts gain-adjusted respectively.Use at least one control channel modulator 616 that at least one is modulated by the unoccupied channel signal that processor controls 608 provides, a modulated control channel signal is provided.Then, the control channel signals of 610 pairs of modulation of gain controller carries out gain-adjusted.In one exemplary embodiment, processor controls 608 provides gain control signal, and this gain control signal decision gain controller 610 will be applied in the gain on each signal.As selection, gain control signal also can be provided by an additional processor controls (not shown).

Processor controls 608 provides unappropriated channel signal according to occupied signal in the code tree 220.Unappropriated signal or signal can format by in question any method of Fig. 5.For example, can whether occupied with single-bit indication code C (128,1) 206.As selection, also can indicate except list 64 chip code outside the C (64,0) 208 with single-bit, as 64 chip code C (64,1) (not shown), whether occupied.Perhaps, with one in one group of unappropriated sign indicating number of different spreading factors possibilities of many bit recognition.

In one exemplary embodiment, processor controls 608 allocated code channels in case data signal use when giving subscriber station.In order to make short bandspread factor code can be used for the possibility maximum that subscriber station is used as Noise Estimation, just only all have under all occupied situation of sign indicating number of identical spreading factor the short bandspread factor code of being scheduled to that is designated as few use are distributed processor controls 608 at other.For example, as mentioned above, processor controls 608 can guarantee C (32,31) 218 as far as possible, C (64,63) 216, and C (128,127) 214 is not occupied, and indicates unappropriated short spreading factor with one 2 bit message.For example, " 00 " expression does not have unappropriated channel, and " 01 " expression C (32,31) is unoccupied or the like.Processor controls 608 is preserved the short bandspread factor code of being appointed as few use as far as possible.

In one exemplary embodiment, be added in together in adder 618 through CPICH, the P-CCPCH of gain-adjusted, the data-signal and the modulated control signal of modulation, adder is added up each signal and is formed the transmission signal of a combination.Then, the transmission signal of combination multiply by a scrambler at scrambler 622 and obtains a disturbing signal.Scrambling code generator 620 provides scrambler for scrambler 622.The scrambler that the scrambler that is provided by scrambling code generator 620 should generate with the scrambling code generator 518 in the subscriber station 102 is identical.Therefore, as mentioned above, the scrambler that scrambling code generator 620 provides may be real number or complex code.Scrambler also can be a pseudo-code (PN) sign indicating number.The transmitting of combination that adder 618 provides is under the situation of complex signal, and scrambler 622 is carried out complex multiplication and come transmitting of this combination carried out disturbance.The disturbing signal that scrambler 622 generates is carried out up-conversion in upconverter (UCVT) 624, in high power amplifier (HPA) 626, amplifies, and from antenna 114 emissions.As mentioned above, many antennas may be used in base station 112 under the situation that does not depart from present embodiment.

The insider can recognize further that illustrative logical blocks, module, circuit and algorithm steps that embodiment that various and this paper sets forth interrelates can realize by electronic hardware, computer software or method that both combine.For the interchangeability of this hardware and software clearly is described, various example components, logical block, module, circuit and algorithm steps all mainly are described in the above from their function.Such function is to realize the restriction depending on concrete application and design suffered total system by hardware or software.The insider who is skilled in technique may realize above representation function for each concrete application by various method, and not talkative one-tenth has departed from category of the present invention but these carry out decision.

Schematic logical block, module, circuit and the algorithm steps that the embodiment that this paper sets forth relates to can be carried out or realization with following equipment: general processor, digital signal processor (DSP), application-specific integrated circuit (ASIC) (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, the perhaps wherein several combination arbitrarily that designs according to above-described function.This realization can be applicable to control channel demodulator 510, short SF despreader 512, noise estimator 516, and part such as processor controls 520.In addition, general processor can be a microprocessor, but as selecting, and processor also can be conventional processors, controller, microcontroller or state machine arbitrarily.Controller can also by several computing equipments in conjunction with realizing, for example, microprocessor and DSP, a plurality of microprocessor, one or more microprocessor that links to each other with the DSP core, perhaps any other combination of this structure.

The method that the embodiment that this paper sets forth relates to or each step of algorithm can directly realize with hardware, perhaps carry out with the software module of processor, perhaps both are combined.Software module may be stored in the storage medium of RAM memory, flash memory, ROM memory, eprom memory, eeprom memory, register, hard disk, moveable magnetic disc, CD-ROM or any other form known in the art.The storage medium of a demonstration is connected with processor, and processor just can read information from storage medium like this, and to the storage medium write information.As selection, storage medium also can be integrated in the processor.Processor and storage medium may be on a slice application-specific integrated circuit (ASIC)s (ASIC).This ASIC may be installed in the subscriber station.As selection, processor and storage medium also can be used as discrete device and are installed in the subscriber station.

Providing preamble for by the description of illustrated embodiments, is can make or use the present invention for the insider who makes this area.Is conspicuous for the various modifications of these embodiment to the people of this area, and the principle of the universality that this paper describes in detail also can be applied among other the embodiment under the situation that does not depart from total inventive concept of the present invention and category.Therefore the present invention is not the embodiment shown in being limited to here, but will be awarded and principle disclosed herein and novel features the wideest corresponding to scope.

Claims (18)

1, a kind of noise measuring method comprises:

Determine that a short bandspread factor code is unoccupied, wherein said short bandspread factor code has the short spreading factor littler than the longest spreading factor;

Measure the symbol energy that first symbol energy provides first to record based on described short bandspread factor code;

Measure second symbol energy based on described short bandspread factor code second symbol energy that records is provided; And

Difference based between the described symbol energy that first records and described second symbol energy that records generates first Noise Estimation;

Wherein, described short spreading factor be the longest spreading factor 1/4th, and wherein, described short bandspread factor code and two bandspread factor codes the longest have common father's sign indicating number, wherein first in two spreading codes the longest is occupied always, and the longest wherein said bandspread factor code all has the spreading factor that equates with the longest described spreading factor;

Described method further comprises:

Determine described two second of the longest bandspread factor code be in unoccupied state with predetermined duty factor;

Measure the 3rd symbol energy based on described short bandspread factor code the 3rd symbol energy that records is provided;

Measure the 4th symbol energy based on described short bandspread factor code the 4th symbol energy that records is provided; And

Difference based on described the 3rd symbol energy that records and described the 4th symbol energy that records, generate second Noise Estimation, wherein measure first symbol energy, measure second symbol energy, measure the 3rd symbol energy, measure the 4th symbol energy, occur in respectively in four continuous code symbol period, described four continuous code symbol period are present in the maximum length code symbol period relevant with the maximum length code symbol with the longest spreading factor.

2, the method for claim 1 further comprises receiving a unappropriated message of the short bandspread factor code of indication, wherein saidly determines to be based on described message.

3, method as claimed in claim 2, wherein, described message is a single bit, and wherein, described short bandspread factor code is C (128, a 1) sign indicating number, and wherein said short spreading factor is 128.

4, method as claimed in claim 2, wherein, described message is a single bit, and wherein, described short bandspread factor code has the length that is less than or equal to 128 chips, and is sign indicating number rather than C (128, the 1) sign indicating number of being scheduled to.

5, method as claimed in claim 2, wherein, described message is a single bit, and wherein, described short bandspread factor code is the sign indicating number of being scheduled to 64 chip lengths.

6, method as claimed in claim 2, wherein, described message is a single bit, and wherein, described short bandspread factor code is the sign indicating number of being scheduled to 32 chip lengths.

7, method as claimed in claim 2, wherein, described message is more than a bit, and from a group code with different chip lengths the described short bandspread factor code of identification.

8, the method for claim 1, wherein described short bandspread factor code and at least one the longest occupied bandspread factor code have common father's sign indicating number, and wherein, the longest described bandspread factor code has the spreading factor that equates with the longest described spreading factor.

9, a kind of noise measuring equipment comprises:

Be used for determining the unappropriated device of short bandspread factor code, wherein said short bandspread factor code has the short spreading factor littler than the longest spreading factor, wherein, the spreading factor of described short bandspread factor code be the longest spreading factor 1/4th;

Be used for measuring the device that first symbol energy provides first symbol energy that records based on described short bandspread factor code;

Be used for measuring the device that second symbol energy provides second symbol energy that records based on described short bandspread factor code;

Be used for generating the device of first Noise Estimation based on the difference between the described symbol energy that first records and described second symbol energy that records;

Be used for measuring the device that the 3rd symbol energy provides the 3rd symbol energy that records based on described short bandspread factor code;

Be used for measuring the device that the 4th symbol energy provides the 4th symbol energy that records based on described short bandspread factor code; With

Be used for determining the device of second Noise Estimation by the difference between described the 3rd symbol energy that records and described the 4th symbol energy that records;

Wherein measure first symbol energy, measure second symbol energy, measure the 3rd symbol energy, measure the 4th symbol energy, occur in respectively in four continuous code symbol period, described four continuous code symbol period are present in the maximum length code symbol period relevant with the maximum length code symbol with the longest spreading factor.

10, a kind of noise measuring equipment comprises:

Processor controls is configured to be used for determine that a short bandspread factor code is unoccupied, and wherein said short bandspread factor code has the short spreading factor littler than the longest spreading factor;

Despreader is configured to measure first symbol energy based on described short bandspread factor code first symbol energy that records is provided, and provides second symbol energy that records based on second symbol energy of described short bandspread factor code measurement;

Noise estimator is configured to generate first Noise Estimation based on the described symbol energy that first records and described second difference that records between the symbol energy;

Wherein, the spreading factor of described short bandspread factor code be the longest spreading factor 1/4th, wherein said despreader further is configured to measure four symbol energies on four continuously short spreading factor code symbol period in the spreading factor code symbol period the longest, and the 3rd and the 4th symbol energy that records except described first and second symbol energy are provided;

Wherein, the described noise estimator difference that further is configured to be used for by between described the 3rd symbol energy that records and described the 4th symbol energy that records is determined second Noise Estimation.

11, equipment as claimed in claim 10, further comprise the control channel demodulator, it is configured to demodulation and indicates the unappropriated message of described short bandspread factor code, and wherein said processor controls determines that based on described message described short bandspread factor code is unoccupied.

12, equipment as claimed in claim 11, wherein said control channel demodulator is configured to message is decoded into single bit, wherein said despreader is configured to use C (128, the 1) sign indicating number of short spreading factor to measure described first and second symbol energy.

13, equipment as claimed in claim 11, wherein said control channel demodulator is configured to message is decoded into single bit, wherein said despreader be configured to use the predetermined short bandspread factor code relevant with described single bit measure described first with second symbol energy, wherein said predetermined short bandspread factor code has the length that is less than or equal to 128 chips.

14, equipment as claimed in claim 11, wherein said control channel demodulator is configured to message is decoded into single bit, wherein said despreader be configured to use the predetermined short bandspread factor code relevant with described single bit measure described first with second symbol energy, wherein said predetermined short bandspread factor code has the length that equals 64 chips.

15, equipment as claimed in claim 11, wherein said control channel demodulator is configured to message is decoded into single bit, wherein said despreader be configured to use the predetermined short bandspread factor code relevant with described single bit measure described first with second symbol energy, wherein said predetermined short bandspread factor code has the length that equals 32 chips.

16, equipment as claimed in claim 11, the message that wherein said control channel demodulator is configured to decode is more than 1 bit, wherein said despreader is configured to based on described message more than 1 bit, uses the predetermined group code with different chip lengths to measure described first and second symbol energy.

17, equipment as claimed in claim 11, wherein said noise estimator further is configured to provide two Noise Estimation for each the longest spreading factor code symbol period, in described two Noise Estimation first is first Noise Estimation, determines second Noise Estimation by the difference between described the 3rd symbol energy that records and the 4th symbol energy that records.

18, equipment as claimed in claim 17, wherein said processor controls are configured to further determine when unoccupied a bandspread factor code the longest is during a predetermined duty factor.

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