• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: An apparatus and method for searching an adjacent BTS(Base Transceiver Station) of an MS(Mobile Station) is provided to search the adjacent BTS for a soft handover in the MS. CONSTITUTION: A channel estimator(32) estimates a channel from a random slot of a random path of a multi-path signal received from a home BTS, outputs the estimated channel, and outputs multi-path signal arrival signal information. A controller(33) stores a part of time index having a relatively high auto-correlation function value among sampling values of an auto-correlation function of a primary synchronous channel code signal received from the home BTS and a weight value according to the time index, receives multi-path signal arrival time information, and outputs a timing signal. A multiplier(31) multiplies a channel estimating value to a corresponding path, a weight value according to the time index inputted from the controller(33), a transmission diversity indication bit to a common control physical channel, and a primary synchronous channel power to a common pilot channel power ratio under the control of the timing signal of the controller(33). Subtracters(34,35) subtract an output signal of the multiplier(31) from an output signal of a primary synchronous channel matching filter(11) according to each channel and provide the subtracted value to a non-coherent combiner(12).
    公开号:KR20020022409A
    申请号:KR1020000055185
    申请日:2000-09-20
    公开日:2002-03-27
    发明作者:김일규；원석호；방승찬
    申请人:오길록；한국전자통신연구원；
    IPC主号:
    专利说明:

    Neighbor Cell Search scheme and method for W-CDMA Mobile station
    [11] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an asynchronous wideband code division multiple access system, and more particularly, to an apparatus and method for a mobile station searching for a neighbor base station for soft handover in an asynchronous wideband code division multiple access system. It is about.
    [12] It is a ground-based wireless multiple access technology of Future Public Land Mobile Telecommunication System or International Mobile Telecommunication in the year 2000. Currently, many countries in the world adopt W-CDMA technology. The W-CDMA system is classified into a base station synchronous method and a base station asynchronous method.
    [13] In general, the base station synchronization method distinguishes each base station using an offset of the same code with respect to the absolute time, whereas the base station asynchronous method distinguishes each base station using different long codes. That is, the asynchronous W-CDMA scheme distinguishes each base station by a different spreading code for each base station. The number of spreading codes used in the system is 512.
    [14] In the asynchronous W-CDMA scheme, one frame has a length of 10 msec, which corresponds to a long code length. The base station transmits a common pilot channel (CPICH) signal as shown in FIG. 1 on the forward link, which is an unmodulated channel spread with a long code unique to the base station.
    [15] As mentioned earlier, the asynchronous W-CDMA scheme not only distinguishes each base station with 512 different codes, but since the frame boundary is independent for each base station, the search time can be very long when searching for a base station using an existing active correlator. In order to reduce the base station search time, the W-CDMA scheme divides 512 long codes into 64 long code groups, and puts two sync channels on the forward link as shown in FIG.
    [16] In the forward sync channel structure of FIG. 1, the primary sync channel code 1 is composed of a Generalized Hierachical Golay (GHG) code having an unmodulated 256-chip length, that is, once at a slot boundary for each slot (2560 chips). It is transmitted 15 times per frame and all base stations of the system use the same code as the primary sync channel code. In FIG. 1, c represents a primary synchronization channel code. The primary sync channel provides the mobile station with information about the slot starting point.
    [17] In FIG. 1, the Secondary Synchronization Channel Code 2 also has a 256-chip length, but different codes corresponding to the hopping code numbers are transmitted in every slot. The jump code sequence used for the secondary sync channel code is an RS code having a length of 15 (since one frame is 15 slots) and an alphabet size of 16. In FIG. 1, C i 0 C i 1 C i 2 ... C i 14 represent the jump code sequence for group i.
    [18] In the W-CDMA system, the number of hop code sequences used for the secondary synchronization channel is 64, which is equal to the number of long code groups. That is, the secondary sync channel code provides the mobile station with the long code group information of the current base station. The mobile station receives information on the frame boundary from the secondary sync channel code in addition to the long code group information of the current base station. That is, since the 64 hop code sequences used in the system are unique for all cyclic shifts, the secondary sync channel codes provide not only long code group information but also frame information.
    [19] In the asynchronous W-CDMA scheme, the initial synchronization acquisition of the mobile station is achieved through three steps. 2 is a block diagram illustrating a receiver structure of a simplified mobile station for explaining the W-CDMA three-stage base station search algorithm.
    [20] The receiver for initial synchronization acquisition of the asynchronous W-CDMA scheme is transferred to the first stage searcher 4, the second stage searcher 5, the third stage searcher 6, and the controller 7 as shown in FIG. 2. It is composed.
    [21] The first stage searcher 4 finds the starting point of the slot for the base station having the lowest path loss by using a matched filter for the primary synchronization channel. The second stage searcher 5 obtains the long code group information and the information about the starting point of the 10 msec frame by using the correlator for the secondary synchronization channel and the R-S decoding. The third stage searcher 6 finds out the long code used by the current base station by using the frame start point and the long code group information obtained in the previous step. That is, if 8 long codes corresponding to a long code group are correlated using information on frame boundaries and the double maximum value exceeds a preset threshold, the mobile station transmits the long code having the maximum value to the current base station. Declares a long code to use for spread spectrum of the forward link. The mobile station thus obtains information about the frame synchronization and the long code of the current base station. In the third stage searcher 6 the mobile station uses the common pilot channel 3 of FIG.
    [22] 3 is a block diagram showing a detailed structural diagram of the above-described first step searcher 4. Referring to FIG. 3, the first stage searcher is composed of a code matching filter 11, a non-coherent combiner 12, a buffer 13, and a maximum detector 14 for a primary sync channel.
    [23] The first stage searcher 4 finds the starting point of the slot for the base station having the smallest path loss by using the first synchronization channel matching filter 11 and the non-coherent combiner 12. That is, the maximum detector 14 finds a slot boundary by selecting a position having the maximum value of the outputs of the 2560xK non-coherent combiner 12. Where K is the number of hypothesis tests of the first stage searcher per chip. In order to increase the detection probability of the first stage searcher 4 in the fading channel (or in a low SNR environment), a cumulative technique is introduced in the receiver.
    [24] That is, a buffer 13 capable of storing 2560xK sample values is allocated between the non-coherent combiner 12 and the maximum detector 14, so that the output of the 2560xK primary sync channel code matching filter generated in each slot is generated. Add by position across multiple slots. For example, when the cumulative length of the first step is 10 msec, the first sync channel matched filter output is accumulated non-coherently over 15 slots. The receiver finds the slot boundary by selecting the maximum of 2560xK values after 15 slots have been accumulated.
    [25] In FIG. 1, a of the primary sync channel code 1 and the secondary sync channel code 2 indicates to the mobile station whether transmit diversity is used for the common control physical channel (CCPCH) of the current base station. As an indicative bit, after completion of the three-stage base station discovery procedure, the mobile station finds a value by coherent demodulation of the primary synchronization channel or the secondary synchronization channel using a common pilot channel.
    [26] The basic three-stage base station search algorithm for initial synchronization acquisition of the mobile station is also used for neighbor base station search for preparation of soft handover in the mobile station active state. However, the difference between the two discovery processes is that since the number of groups to be searched in the second phase of discovery is 64 when initial synchronization is acquired, the information about the neighbor base station is transmitted from the currently active base station to the mobile station in advance when searching for the neighbor base station. It is much smaller than this.
    [27] As mentioned above, since all base stations use the same primary synchronization channel code, the output of the primary synchronization channel code matching filter in the first stage searcher 4 includes not only neighboring base station components but also home base station components. Therefore, when the reception power from the neighbor base station is less than the reception power from the home base station when searching for the neighbor base station, the first step searcher always selects only the position corresponding to the signal component received from the home base station. 4 is an exemplary view for explaining such a situation.
    [28] 4 shows the output of the non-coherent combiner 12 of FIG. 3 when searching for a neighbor base station. In the figure, 15 (A), 15 (B), and 15 (C) represent multipath components of a home base station, and 16 (A) and 16 (B) represent multipath components of a neighbor base station. In the situation where the multipath component of the home base station is larger than the multipath component of the neighbor base station as shown in FIG. 4, it is almost impossible to search the neighbor base station by using the three-stage base station search method used by the mobile station for initial synchronization acquisition.
    [29] As described above, the conventional three-stage base station search method has no problem in the search performance in the initial search mode, but has a disadvantage in that the performance is very degraded in the neighbor base station search mode for soft handover. In a DS-CDMA system, the mobile station should be able to search for neighboring base stations for constant soft handover. That is, the neighbor base station should be able to be searched not only when the received power from the neighbor base station is larger than the received power from the home base station (or the active base station) but also by the receiver. There is a problem that cannot be explored.
    [30] In order to solve this problem, the neighbor base station search apparatus is configured by adding a location deleter that drives only when searching for a neighbor base station for soft handover to the first step searcher for conventional initial synchronization search.
    [31] FIG. 5 is a diagram illustrating an example of a conventional neighbor base station search apparatus, which deletes positions installed in front of the first stage searchers 11, 12, 13, and 14 and the maximum detector 14 for a conventional initial synchronization search. It consists of a Peak Nulling 17. Since the mobile station already knows the frame boundary or the slot boundary for the multipath component of the signal received from the home base station, the position where the maximum value of the sync channel matched filter output of the home base station received signal exists (15 (A) and 15 in FIG. 4). (B) and 15 (C)) can be known beforehand. The position eraser 17 sets the value corresponding to this position of the matched filter output to 0, thereby preventing the maximum detector 14 at the rear end from selecting this position. As a result, the mobile station can detect the location 16 of the adjacent base station as shown in FIG. 6 to 18 show deleted home base station components.
    [32] The conventional neighbor base station search apparatus described above has the advantage that the receiver structure is not complicated because only the peak nulling to delete the components of the home base station is added. If the slot boundaries coincide, there is a case in which a neighbor base station cannot be searched (worst case). If there is only one home base station and one reception path from the home base station, the probability of such a situation is very small, one in 2560. However, if there are multiple home base stations and the received path is multipath, the probability is increased, and depending on the situation, a situation in which no handover is performed may occur.
    [33] In addition, this conventional method degrades the search performance of neighboring base stations due to the poor autocorrelation characteristics of the primary sync channel code. 7 shows an autocorrelation function of a primary sync channel code. Since the first sync channel code is designed to minimize the complexity of the matched filter, as shown in FIG. 7, the autocorrelation property is not good.
    [34] To solve the problems of the conventional method, another method has been proposed. FIG. 8 is a block diagram illustrating a neighbor base station search apparatus of a mobile station according to the second conventional method. This includes a common first stage searcher (11, 12, 13, 14) for initial synchronization acquisition, a autocorrelation function generator (21) for generating a primary sync channel autocorrelation function, and a common pilot channel among the signals received at the home base station. A channel estimator 23 for estimating a channel through the channel estimator 23, a multiplier 22 for multiplying the primary sync channel autocorrelation function and the estimated channel, a controller 24 for controlling timing according to the position of the home base station primary sync channel, and Two subtractors 25 and 26 subtract the multiplication result signal for each phase from the signal output from the primary synchronization channel matching filter 11.
    [35] This is multiplied by the primary sync channel autocorrelation function and the estimated channel for each channel and subtracted from the signal output from the primary sync channel matched filter 11 to thereby output from the home base station at the output of the primary sync channel matched filter 11. Eliminate all received primary sync channel code signal components.
    [36] FIG. 9 is an exemplary diagram illustrating an output signal component of the non-coherent combiner 12 when the second neighbor base station search apparatus described above is used. 9 illustrates a state in which interference components from the home base station are removed and only noise components exist. The mobile station is able to search for adjacent base station components in the maximum detector 14.
    [37] The second conventional method can overcome all the disadvantages of the first conventional method, but generates an autocorrelation function of 511 samples in each slot and multiplies the channel estimator output values of the real part and the imaginary part, respectively, Since the operation of subtracting this value from the first synchronous channel matched filter output signal of the imaginary part is required, the power consumption of the receiver is very large. In particular, when the number of home base stations is several and the path of the received signal from the home base station is multipath, the computation amount increases in direct proportion to the number of the home base stations and the number of paths, so that the power consumption of the mobile station becomes very large. Has its drawbacks.
    [38] Accordingly, an object of the present invention devised to solve the above problems of the prior art is to overcome the disadvantages of the first conventional method and the second conventional method described above, while the complexity of the receiver is much smaller than that of the second conventional method. In terms of performance, it is to provide a neighbor base station search apparatus and method which is almost similar to the second conventional method.
    [1] 1 is a diagram illustrating a structure of a forward sync channel and a common pilot channel of a general base station asynchronous W-CDMA scheme;
    [2] 2 is a block diagram illustrating a receiver of a mobile station for initial synchronization acquisition according to the prior art in the base station asynchronous W-CDMA scheme;
    [3] 3 is an internal detail view of the first stage searcher of FIG. 2;
    [4] 4 is a diagram illustrating a problem of the prior art, an exemplary view of the output of the non-coherent combiner of FIG. 3 in a handover situation;
    [5] FIG. 5 is a block diagram illustrating a first stage searcher including a location deleter as a first conventional method for solving the problem illustrated in FIG. 4;
    [6] 6 is an exemplary diagram of an output of a non-coherent combiner in a first stage searcher configured as shown in FIG. 5;
    [7] 7 is a graph showing an autocorrelation function of a primary sync channel code of a W-CDMA scheme;
    [8] FIG. 8 is a second conventional method for solving the problem illustrated in FIG. 4, which is a block diagram of a first step searcher for removing all primary synchronization channel components of a home base station in a handover situation.
    [9] 9 is an exemplary diagram of an output of a non-coherent combiner in a first stage searcher configured as in FIG. 8;
    [10] 10 is a block diagram of a first stage searcher including a neighbor base station search apparatus of a mobile station according to an embodiment of the present invention.
    [39] The neighbor base station search apparatus of the mobile station according to the present invention for achieving the above object includes a first synchronization channel matching filter and a non-coherent combiner, and receives the multipath signal from the home base station and the neighbor base station to receive the best reception power. A neighbor base station search apparatus having a first-stage searcher for searching a large neighbor base station, comprising: a multi-correlation function of the home base station output from the primary synchronization channel matching filter, the autocorrelation function including a main wave for each path; And partial interference elimination means for eliminating some lobes having a relatively large value.
    [40] Preferably, the partial interference elimination means estimates and outputs a channel using a common pilot channel in an arbitrary slot of an arbitrary path of the multipath signal received from the home base station, and outputs the multipath signal arrival time information. A channel estimator; A time index of a portion (N) having a relatively large autocorrelation function value among the sampling values of the autocorrelation function of the primary sync channel code signal received from the home base station and its weight are stored, and the multipath signal arrives. A controller for receiving time information and outputting a timing signal; Controlled by the timing signal of the controller, the channel estimate value for the corresponding path, the weight of each time index input from the controller, the transmit diversity indication bit for the common control physical channel, and the primary sync channel power versus common pilot channel A multiplier for multiplying the power ratio; And a subtractor provided by subtracting the output signal of the multiplier for each channel from the output signal of the first synchronous channel matching filter and providing the non-coherent combiner.
    [41] In addition, the neighboring base station search method of the mobile station according to the present invention, receiving a multi-path signal received from the home base station and the neighbor base station through the first synchronization channel matching filter, the maximum detector to search for the neighbor base station with the largest reception power In the neighbor base station search method of,
    [42] A first step of storing a portion (N) of the time index having a relatively large autocorrelation function value and a corresponding weight among sampling values of the autocorrelation function of the primary sync channel code received from the home base station;
    [43] And removing a part of the lobes having a relatively large autocorrelation function value from the multipath signal received from the home base station and providing the non-coherent coupler.
    [44] Hereinafter, an apparatus and method for searching for a neighboring base station of a mobile station according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
    [45] FIG. 10 is a block diagram illustrating a neighbor base station searching apparatus for searching for a neighbor base station of a mobile station according to an embodiment of the present invention.
    [46] Referring to FIG. 10, this is arranged with a general first stage searcher (11, 12, 13, 14) for the initial synchronization acquisition, a multiplier (31), a channel estimator (32), a controller (33), and each phase. Subtractors 34 and 35.
    [47] The first synchronization channel matched filter 11, the non-coherent combiner 12, the buffer 13, and the maximum detector 14 of the first stage searcher are the same as in the conventional operation, and thus detailed description thereof will be omitted. do.
    [48] Before explaining the operation of the present invention will be described the theoretical basis of the present invention.
    [49] As shown in FIG. 7, the autocorrelation function of the primary sync channel code has a value over the -255 to 255 chip intervals. The autocorrelation function is symmetrically around a point where a time index is zero. When the autocorrelation function value of the mainlobe ML is 1.0, the maximum value of the absolute value of the autocorrelation function value of the first side lobe is 0.25 (SL1A, SL1B). In other words, it is mainly about 25% of the ube, the value gradually decreases with time.
    [50] Accordingly, the neighbor base station search apparatus according to the present invention includes N positions having a relatively large size, including mainly a hub (ML), among the outputs of the matched filter during the 511 chip interval for the primary sync channel code signal received from the home base station. By removing only components corresponding to (1 N << 511), the calculation amount is reduced.
    [51] Table 1 summarizes the time index and weight at nine positions (N = 9) where the autocorrelation function values are relatively large. As mentioned above, since the autocorrelation function is bilaterally symmetric and do not need to store the main lobe (because the autocorrelation value in the main lobe is 1), we store only (N-1) / 2 time indexes and their weights. . This time index weight is stored in the controller 33, and once stored, does not change.
    [52] Time index0± 2± 6± 7± 9 WeightOne0.25-0.250.199-0.199
    [53] As shown in the above table, when N is 9, the amount of computation for removing the primary synchronization channel component of the home base station is 9/512, that is, 1.76%, compared to the aforementioned second method.
    [54] The controller 33 stores weights for the time indexes as shown in Table 1, and receives the arrival time information of the multipath signals received from the home base station from the channel estimator 32. In addition, the controller 33 controls the timing of the multiplier 31 by using the stored time index value and the arrival time information of the multipath signals. The multiplier 31 receives the channel estimation value of the channel estimator 32 for the corresponding path under the control of the controller 33 and at the same time receives the weight value from the controller 33 to multiply the multiplication defined in Equation 1 below. Perform for each channel and Q channel. The output of the multiplier 31 is input to the subtractors 34 and 35, respectively, and the subtractors 34 and 35 subtract the output signal of the multiplier 31 from the output signal of the primary synchronous channel code matching filter 11.
    [55] In the case of time index n, the output of the multiplier 31 is expressed as in Equation (1).
    [56]
    [57] In Equation 1, α I and α Q are outputs of the channel estimator 32 using a common pilot channel (CPICH) for a home base station received signal in an arbitrary slot. α I and α Q have completely independent characteristics between the respective paths and have different values, although not completely independent between the slots.
    [58] If the synchronization channel of the home base station transmits the synchronization channel signal in the adjacent slots through different antennas by the Time Switching Transmit Diversity (TSTD) technique using two antennas, the channel estimator 32 of FIG. The channel estimation value for the first antenna is passed for the slot having the number of channels, and the channel estimation value for the second antenna is passed for the slot having the odd number. In this case, α I and α Q have completely independent characteristics between each path and each slot.
    [59] In Equation 1, a is a bit indicating whether transmit diversity is used in a common control physical channel (CCPCH) of a home base station. P PSC / P CPICH is the ratio of primary synchronization channel (PSC) power to CPICH of the home base station, the base station of the present invention transmits this value to all mobile stations in the base station area and the mobile station of the present invention is a soft hand. This value should be received and stored from the base station before the neighbor base station search for over.
    [60] Ω n in Equation 1 is a weight value defined in the present invention for the nth time index value, which is provided from the controller. It is also within the scope of the present invention when N is 1, that is, mainly removing only ubes.
    [61] When searching for a primary synchronization channel of a different frequency in the initial synchronization acquisition mode or the compressed mode, it bypasses the partial interference cancellation function of the neighboring base station search apparatus without operating. Here, the initial synchronization acquisition mode is a moment when power is applied to the mobile station, and the compressed mode is a mode for the mobile station to search for another frequency and is transmitted from the base station to the mobile station through a higher layer message.
    [62] While the invention has been described above based on the preferred embodiments thereof, these embodiments are intended to illustrate rather than limit the invention. It will be apparent to those skilled in the art that various changes, modifications, or adjustments to the above embodiments can be made without departing from the spirit of the invention. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.
    [63] As described above, according to the present invention, there is a problem with the conventional method for searching for the neighboring base station, that is, if the slot boundary of the signal received from the home base station and the neighboring base station is identical, the neighboring base station cannot be searched, and the primary The problem that the search performance of neighboring base stations is degraded due to the poor autocorrelation property of the sync channel code is solved. In addition, the problem of the conventional second neighbor base station search method is solved, that is, a large amount of calculation for the primary synchronization channel interference cancellation of the home base station is very large power consumption of the mobile station is solved. Therefore, the receiver equipped with the neighbor base station search apparatus according to the present invention has an advantage of smoothly performing soft handover while keeping the power consumption of the terminal to a minimum when used in an asynchronous W-CDMA mobile station.
    权利要求:
    Claims (5)
    [1" claim-type="Currently amended] A neighbor base station search apparatus including a first sync channel matching filter and a non-coherent combiner, and having a first stage searcher receiving a multipath signal from a home base station and a neighbor base station and searching for a neighbor base station having the largest reception power,
    And a partial interference elimination means for receiving a multipath signal of the home base station output from the primary synchronization channel matching filter and removing some lobes having a relatively large autocorrelation function value including a main wave for each path. Neighbor base station search apparatus for a mobile station.
    [2" claim-type="Currently amended] The method of claim 1,
    The partial interference removing means,
    A channel estimator for estimating and outputting a channel using a common pilot channel in an arbitrary slot of an arbitrary path of the multipath signal received from the home base station, and outputting the multipath signal arrival time information;
    A time index of a portion (N) having a relatively large autocorrelation function value among the sampling values of the autocorrelation function of the primary sync channel code signal received from the home base station and its weight are stored, and the multipath signal arrives. A controller for receiving time information and outputting a timing signal;
    Controlled by the timing signal of the controller, the channel estimate value for the corresponding path, the weight of each time index input from the controller, the transmit diversity indication bit for the common control physical channel, and the primary sync channel power versus common pilot channel A multiplier for multiplying the power ratio; And
    And a subtractor for subtracting the output signal of the multiplier for each channel from the output signal of the first synchronous channel matching filter and providing the noncoherent combiner to the non-coherent combiner.
    [3" claim-type="Currently amended] The method of claim 2,
    And the N value is greater than or equal to 1 and much smaller than the total number of sampling of the autocorrelation function.
    [4" claim-type="Currently amended] A method for searching for a neighboring base station of a mobile station for receiving a multipath signal received from a home base station and a neighboring base station through a primary sync channel matching filter and a non-coherent combiner and searching for a neighboring base station having the largest reception power,
    A first step of storing a portion (N) of the time index having a relatively large autocorrelation function value and a corresponding weight among sampling values of the autocorrelation function of the primary sync channel code received from the home base station;
    And removing a part of the lobes having a relatively large autocorrelation function value from the multipath signal received from the home base station and providing the non-coherent combiner to the non-coherent combiner.
    [5" claim-type="Currently amended] The method of claim 4, wherein
    The second step,
    Receiving a multipath signal from the home base station, estimating and outputting a channel using a common pilot channel in an arbitrary slot of an arbitrary path, and outputting the multipath signal arrival time information;
    Multiplying the time index weight stored in the first step, the channel estimate estimated in the first sub-step, the transmit diversity indication bit for the common control physical channel, and the primary sync channel power to common pilot channel power ratio. 2 substeps; And
    And a third substep of subtracting the multiplication result value of the second substep from the output signal of the first synchronization channel matching filter for each channel and providing the result to a non-coherent combiner. .
    类似技术:
    公开号 | 公开日 | 专利标题
    DE60118715T2|2007-04-19|Correlation filter for the reverse channel in a wireless cdma system with multiple bit rates
    US5703873A|1997-12-30|Method and apparatus for synchronizing subscriber equipment with base stations in a CDMA radio network
    KR100467543B1|2005-01-24|Path search method, channel estimation method, and communication systems
    US7965759B2|2011-06-21|Synchronization codes for wireless communication
    KR100254751B1|2000-05-01|Reception timing detection circuit of cdma receiver and detection method
    DE60220409T2|2008-01-24|Device and method for carrying out initial cell search in a wireless communication system
    JP4263368B2|2009-05-13|Apparatus and method for interference cancellation in spread spectrum communications
    JP3407711B2|2003-05-19|Path search circuit in DS-CDMA receiver
    AU756272B2|2003-01-09|Cellular system, mobile portable apparatus, base station apparatus, optimum path detecting method, and apparatus thereof
    EP1235360B1|2006-03-08|Communication terminal apparatus and demodulation method
    US7349461B2|2008-03-25|Efficient back-end channel matched filter |
    AU756683B2|2003-01-23|Appararus and method for synchronizing channels in a W-CDMA communication system
    US6847630B2|2005-01-25|Communications in an asynchronous cellular wireless network
    DE60111278T2|2006-03-16|A cell search method and apparatus in an asynchronous wideband CDMA receiver
    KR100705064B1|2007-04-06|Combining sub-chip resolution samples in fingers of a spread-spectrum rake receiver
    US8411552B2|2013-04-02|Cell search method in OFDM cellular system, frame transmission method thereof, and forward link frame structure thereof
    KR100950904B1|2010-04-06|Initial cell search in wireless communication systems
    JP3028800B2|2000-04-04|CDMA cellular system and spreading code detection method in CDMA cellular system
    US7317749B2|2008-01-08|Pilot signals for synchronization and/or channel estimation
    AU692006B2|1998-05-28|De-spread code phase detection apparatus in spread spectrum type receiver
    US6175587B1|2001-01-16|Communication device and method for interference suppression in a DS-CDMA system
    US6404760B1|2002-06-11|CDMA multiple access interference cancellation using signal estimation
    KR100726050B1|2007-06-08|Method and apparatus for efficient synchronization in spread spectrum communications
    EP1173931B1|2004-11-03|Cell search apparatus and method in cdma mobile communication system
    Wang et al.2000|Cell search in W-CDMA
    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2000-09-20|Application filed by 오길록, 한국전자통신연구원
    2000-09-20|Priority to KR1020000055185A
    2000-09-20|Priority claimed from KR1020000055185A
    2002-03-27|Publication of KR20020022409A
    2002-08-07|Application granted
    2002-08-07|Publication of KR100347512B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR1020000055185A|KR100347512B1|2000-09-20|Neighbor Cell Search scheme and method for W-CDMA Mobile station|
    [返回顶部]