WO2003009505A1 - Procede permettant la reduction de brouillage dans des voies adjacentes dans un systeme de communications a acces multiple par repartition de code (amrc) - Google Patents
Procede permettant la reduction de brouillage dans des voies adjacentes dans un systeme de communications a acces multiple par repartition de code (amrc) Download PDFInfo
- Publication number
- WO2003009505A1 WO2003009505A1 PCT/CN2001/001187 CN0101187W WO03009505A1 WO 2003009505 A1 WO2003009505 A1 WO 2003009505A1 CN 0101187 W CN0101187 W CN 0101187W WO 03009505 A1 WO03009505 A1 WO 03009505A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- mobile station
- code
- interference
- delay
- base station
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/707—Spread spectrum techniques using direct sequence modulation
- H04B1/7097—Interference-related aspects
- H04B1/7103—Interference-related aspects the interference being multiple access interference
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/707—Spread spectrum techniques using direct sequence modulation
- H04B1/709—Correlator structure
- H04B1/7095—Sliding correlator type
Definitions
- the present invention relates to the technical field of spread spectrum and C-plane A mobile communication, and in particular, to a method for reducing adjacent channel interference (ACI) in a CDMA mobile communication system.
- ACI adjacent channel interference
- DS-SS direct-sequence spread-spectrum
- CDMA code division multiple access
- the capacity of a CDMA communication system depends only on the signal-to-interference ratio, and has the characteristics of large capacity and soft capacity. Adding users will only reduce the signal-to-interference ratio, reduce the communication quality, and will not be rejected. That is, the system capacity does not have an insurmountable limit value like frequency division multiple access (FDMA) or time division multiple access (TDMA).
- FDMA frequency division multiple access
- TDMA time division multiple access
- the capacity of the C-A communication system depends on the level of interference within the system. Therefore, the ability to control the interference level in the system will become the key to the success or failure of the CDMA communication system.
- Interference can be divided into four major parts: First, the local and internal noise levels, there is no other method except for using low-noise amplifiers; Second, inter-symbol also known as inter-symbol interference (ISI); Third, multiple-access interference ( MAI), that is, interference from other users in the cell; the fourth is adjacent cell or inter-channel interference (ACI).
- ISI inter-symbol interference
- MAI multiple-access interference
- ACI adjacent cell or inter-channel interference
- it can be reduced or even eliminated by selecting an address code with good performance or some control methods. 01 01187 In the C-A communication system, each user has its own unique address code for identification.
- the spreading address codes of each user should be orthogonal to each other. This orthogonality requirement is consistent for any multiple-access system.
- the autocorrelation function at the origin of the address code as the main peak of the correlation function
- the autocorrelation or cross-correlation function outside the origin as the secondary peak of the correlation function.
- the auto-correlation between ideal multiple access codes and the secondary peaks of the cross-correlation function should all be zero.
- PCT / CN00 / 00028 The application number is PCT / CN00 / 00028, the inventor is Li Daoben, and the invention name is "A Spread Spectrum Multiple Access Coding Method with Zero Correlation Window"
- PCT patent application discloses a spread spectrum multiple address code with zero correlation window , Is called LS code, because LS code is composed of C code and S code, it is also called CS code.
- LS code a spread spectrum multiple address code with zero correlation window
- LS code a spread spectrum multiple address code with zero correlation window
- LS code is composed of C code and S code, it is also called CS code.
- the method of generating the LS code is described in detail in PCT / CN00 / 00028, which is omitted here, and this document is incorporated herein by reference.
- the designed spread-spectrum multi-address code with an interference-free window has the following two characteristics: First: The auto-correlation function of each spread-spectrum address code is zero except for the origin, that is, its Has the best characteristics. From the perspective of orthogonality, each spread-spectrum address code is completely orthogonal to any non-zero delay except for the zero delay. Second: The cross-correlation function between spreading address codes has a "no interference window" near the origin. From an orthogonality perspective, the relative delay between each spreading address code is less than the width of the "no interference window" Time is completely orthogonal.
- the above-mentioned spreading address code design method of the LS code enables the correlation function of the newly formed spreading address code to form an "interference-free window (IFW)" near the origin, so that the corresponding two-way synchronous code division multiple access system does not
- IFD interference-free window
- MAI multiple access interference
- ISI inter-symbol interference
- ACI adjacent channel interference
- the adjacent channel interference (CI) also exists in other CLA communication systems.
- each cell uses a unique PN offset (PN Offset) PN code to spread the signal in the cell. It also does not completely make the adjacent channel interference CI of adjacent cells disappear.
- PN Offset unique PN offset
- any technology that reduces adjacent channel interference is beneficial to increasing system capacity and improving system performance.
- the correlation characteristics of the LS code are good, and the cross-correlation is zero in the "interference-free window (IFW)"; outside of the “interference-free window (IFW)", it is only the channel in the neighboring cell and the channel in the local cell at some points
- the peak value of the related sub-peaks is larger, and the sub-peaks in other regions are smaller.
- IFW No Interference Window
- the cross-correlation peaks of the two LS codes are larger; and the peaks of the cross-correlation of other phase difference values are smaller, or even equal to zero. Therefore, in a system based on the LS code, when the phase difference between the signals is an integer multiple of a certain period, the adjacent channel interference is large; while in other cases, the interference is small.
- phase difference points correspond to some areas between the base stations in the cell, so that mobile stations in these areas are subject to large adjacent channel interference, while mobile stations in other areas are less vulnerable to interference. . Furthermore, the sensitivity of the mobile station to the adjacent channel interference is increased.
- the correlation between the spreading address codes used may also have larger peaks at some points and smaller peaks at other points Even the distance between the larger points of the secondary peaks has a certain periodicity.
- the forward delay control of the code channel is used to make most of the signal phase difference between adjacent channels at the receiving end avoid such a point with a large correlation sub-peak, it will inevitably reduce the adjacent channel interference of the system, or at least The interference is evenly distributed to all areas of the cell, so that the interference in some areas is large and the interference in some areas is small.
- the benefits for mobile station handover are even more obvious.
- an object of the present invention is to provide a method for reducing or eliminating adjacent channel interference to solve the above problems.
- the CDMA communication system includes at least one base station and at least one mobile station.
- the method is characterized in that it includes the following steps:
- the mobile station detects adjacent channel interference to the code channel used by the mobile station
- the code channel used by the mobile station avoids the situation of being subject to large interference from other channels, or makes the interference of mobile stations in all directions in the cell uniform, without the interference in some areas being much larger In other regions.
- the corresponding CDMA communication system can reduce adjacent channel interference or make the distribution of adjacent channel interference uniform.
- FIG. 1 shows a block diagram of a conventional wireless communication system
- FIG. 1 illustrates a process in which a base station according to the present invention adjusts a forward delay of a code channel used by a mobile station
- FIG. 3 illustrates a process in which a mobile station according to the present invention adjusts a forward delay of a used code channel
- FIG. 4 illustrates An auto-correlation result of an LS code
- FIG. 5 shows a cross-correlation result of an LS code
- FIG. 6 shows a distribution diagram of adjacent channel interference between two cells in a LAS-CDMA system
- FIG. 7 shows a process of reducing adjacent channel interference according to the present invention.
- FIG. 1 shows a conventional block diagram describing a wireless communication system.
- mobile stations MS1 and MS2 receive signals of corresponding base stations BTS1, BTS2, and BTS3 in neighboring cells C1, C2, and C3.
- the signals sent by base stations BTS2 and BTS3, if they can be detected by mobile station MS1, are adjacent channels for mobile station MS1.
- Interference UCI Specifically, it is assumed that the base station BTS2 provides services for the mobile station MS2, and the signal sent by the base station BTS2 to the mobile station MS2 is adjacent channel interference to the mobile station MS1.
- FIG. 2 shows a process of adjusting a code channel delay used by a mobile station according to the present invention.
- the base station BTS1 receives the signaling of the mobile station MS1. Then, the flow proceeds to step S202 o
- step S202 the operation determines whether the mobile station MS1 is a request for a channel.
- step S203 the base station BTS1 determines whether the positioning information of the mobile station MS1 has been obtained, that is, whether the position of the mobile station MS1 has been obtained.
- the positioning information can be obtained in two ways: the base station BTS1 tracking the mobile station MS1 or the mobile station MS1 measuring the signal sent by the base station BTS1. If "yes", then the procedure ⁇ step S204.
- step S204 the base station BTS1 determines the forward delay of the currently allocated code channel according to the positioning information. The specific process will be described below. Then, the flow proceeds to step S2G6, and in step S206, the base station BTS1 adjusts the forward delay amount of the code channel.
- step S207 the base station BTS1 notifies the mobile station MS1 of the processing result by using signaling. If it is determined in step S203 that the base station BTS1 has not obtained the positioning information of the mobile station MS1, then the flow proceeds to step S205. In step S205, the base station BTS1 determines the forward delay according to the average occurrence of the delay amount of each code channel. Subsequently, the flow proceeds to step S206.
- step S208 the base station BTS1 determines whether the mobile station MS1 makes a code channel delay adjustment request. If "YES”, the flow proceeds to step S209.
- step S209 the base station BTS1 determines whether the code channel delay of the mobile station MS1 after the delay exceeds a certain range. If the adjustment range is not exceeded, the flow proceeds to step S206. If it is determined in step S209 that the base station BTS1 determines that the delay amount of the code channel of the mobile station MSI exceeds a certain range, then the flow advances to step S210.
- the so-called delay adjustment range can be determined by the width of the "no interference window” and the multiple delays of the wireless communication environment.
- the width of the "no interference window” is 7 chips, and the delay between the earliest and latest paths is 2 chips.
- the adjustment of the delay amount should be within the range of 4 to 5 chips. To ensure that the amount of all delays is less than the difference between the width of the "no interference window" and the multi-pass delay.
- step S210 the base station does not adjust the forward delay amount of the code channel used by the mobile station MS1, and proceeds to step S2Q7.
- step S207 the base station BTS1 notifies the mobile station MS1 of the processing result through signaling, and proceeds to step S211, which ends the control flow.
- step S208 if the base station BTS1 determines that the mobile station MSI has not performed a code channel delay adjustment request, the flow proceeds to step S211.
- FIG. 3 illustrates a process in which a mobile station according to the present invention adjusts the amount of forward delay of a used code channel.
- the mobile station MSI receives the signaling and data of the base station BTS1. Then, the flow proceeds to step S302.
- the mobile station MS1 determines whether the base station BTS1 notifies the processing result of its code channel delay. If "yes", the flow proceeds to S303.
- the mobile station adjusts the receiver of MS1 according to the code channel delay data sent by the base station BTS1, and proceeds to step S304.
- step S302 the mobile station MS1 determines that the base station BTS1 has not notified the forward delay processing result of the used code channel, the flow proceeds to step S304.
- step S304 the mobile station MS1 measures the signal energy and reception delay of signals of all neighboring base stations, that is, the base stations BTS1, BTS2, and BTS3, and proceeds to step S305.
- step S305 the mobile station MS1 measures the energy of the received adjacent channel interference. Then, the flow advances to step S306.
- step S306 the mobile station MS1 determines whether the received adjacent channel interference energy exceeds a preset threshold, and a specific setting method of the threshold is described below. If "YES”, the flow proceeds to step S307.
- step S307 the mobile station MS1 determines whether it is possible to determine its own position according to the energy and reception delay of all adjacent base station signals obtained in step S304. If "YES", the flow proceeds to step S308. In step S308, the mobile station MSI determines a code channel delay adjustment amount according to the positioning information. Then, the flow proceeds to step S309. In step S309, the mobile station MS1 sends an adjustment amount and an adjustment request to the base station BTS1. The flow then proceeds to step S310 and ends. If in step S307, the mobile station MS1 determines that it cannot determine its position based on the measured signal of the base station, the flow proceeds to step S311. In step S311, the mobile station MS1 randomly generates a code channel delay adjustment amount, and proceeds to step S309.
- step S306 in FIG. 3 The setting of the preset threshold in step S306 in FIG. 3 is described below to explain the process of determining the forward delay amount of the code channel in step S204 in FIG. 2 and step S308 in FIG. 3.
- the present invention will mainly be described in detail around a LAS-C belly A system with a width of 7 chips and a code length of C and S codes of 8 chips, but it does not mean that the present invention is limited to this. . this invention (DS-SS).
- Figure 4 is the autocorrelation result of an LS code, where the code length of C code and S code are 8 and the IFW width is 7.
- the abscissa is the correlation offset, the unit is chip, and the ordinate is the correlation value.
- the value of the ordinate at the abscissa 0 is the relevant main peak, which is 16 here, and all other places where the ordinate is not 0 are the relevant auxiliary peaks.
- Figure 5 shows the cross-correlation results of the two codewords in the LS code group. All places where the ordinate is not 0 are related subpeaks. It can be seen from Fig. 4 and Fig.
- the interval (-3.5, 3.5) is a "no interference window" with a width of 7 chips.
- the existence of "no interference window” is a characteristic of LS codes. As the length of the codeword, the number of codewords in the code group, and the composition of the codeword differ, the width of the "no interference window" may be different.
- the case where the absolute value of the secondary peak is 4 is the most common.
- the preset threshold in step S306 in FIG. 3 can be set to 25% of the energy of the relevant main peak, that is, 4 units. Same energy unit as the main peak. Therefore, when the received ACI interference energy is greater than 25% of the main peak energy, the mobile station MS1 considers that it has suffered strong adjacent channel interference (ACI), and then generates a forward code channel delay request.
- ACI adjacent channel interference
- step S204 in FIG. 1 and step S308 in FIG. 3 The following describes a method commonly used in step S204 in FIG. 1 and step S308 in FIG. 3 to determine the forward delay amount of a code channel according to the positioning information.
- the adjacent channel interference to the mobile station is larger at this time, and the adjacent channel interference is smaller in other cases.
- the chip rate of the system is 1228800 chips / s.
- Figure 6 shows the distribution of adjacent channel interference in the second cell of the LAS-CDMA system.
- formula (3) is a condition to be satisfied when the adjacent channel interference is large. Since the trajectory of the point where the difference between the two fixed-point distances is a certain value is a hyperbola, corresponding to each value of i, two hyperbola are formed between the two base stations BTS1 and BTS2. As shown in FIG. 6, in the area near these hyperbola, the adjacent channel interference experienced by the mobile station is relatively large. Since a chip is equivalent to a distance of 244 meters, and a chip is a signal distinguishing unit of the current CDMA system, each hyperbola in FIG. 6 represents a zone with a width of about 244 meters. Theoretically, when the distance between the two base stations is exactly equal to 4 * i chips, the area band on the extension line of the line segment between the two base stations BTS1 and BTS2 is also a region with large adjacent channel interference.
- the adjacent channel interference is small in areas other than the hyperbola, although the time difference between the signals transmitted by the two base stations BTS1 and BTS2 to point G1 cannot be changed, the downlink used by the mobile station at point G1 can be changed.
- the delay of the channel relative to other code channels changes the phase difference of the code sequence between the code channel and the code channel transmitted by another base station.
- FIG. 7 illustrates a process of reducing adjacent channel interference according to the present invention.
- the mobile station MS1 uses the downlink code channel 2 in the base station BTS 1 and the mobile station MS2 uses the downlink code channel 2 in the base station BTS2; and the code channels 1 and code channels in the base station BTS 1 and BTS2 signals 4 are standard delay code channels, that is, the code channel delay is zero.
- the mobile stations MS1 and MS2 are both within the area represented by a certain curve described in FIG. 6, that is, the adjacent channel interference energy will exceed a preset threshold.
- the mobile station MS1 determines that the adjacent channel interference (CI) received exceeds a preset threshold and sends a request, or the base station BTS1 actively makes the code channel 2 used by the mobile station MS1 at the base station according to the positioning information of the mobile station MS1 more
- the code channel is advanced by one chip ( Figure 7 shows the situation after one chip has been advanced), then the phase difference between the code channel 2 and the standard delay code channel in the signal sent by the base station BTS2 is determined by the original
- the increase of 8 chips to 9 chips enables the signal sent by the base station BTS2 to reach the mobile station MS1, avoiding the situation of large adjacent channel interference energy, and reduces the interference to the mobile station MS1.
- the mobile station MS2 also sends a request or the base station BTS2 actively advances the code channel 2 used by the mobile station MS2 one chip ahead of the other code channels, which will cause the standard delayed code channel in the signal sent by the base station BTS1 to the mobile station. MS 2 interference is reduced.
- a mobile station that has not been interfered by a large adjacent channel originally will have a phase difference between the channel and the adjacent channel that satisfies the condition that the adjacent channel interference is large. This is equivalent to putting some The larger interference in the area reaches almost all areas, which reduces the interference in the area with large interference, but increases the interference in the area with small interference.
- mobile stations MS1 and MS2 are located in the cells C1 and C2 covered by the base stations BTS1 and BTS2, respectively.
- the delays of the downlink code channels used by mobile stations MS1 and MS2 are ee 2 in chips; the base stations BTS1 and BTS2 reach the mobile station.
- the distances of MS1 are and r 2 , respectively.
- Table 1 Possible value combinations of ee 2 and possible results of e 2 Consider the possibility of lr 2 - ri
- d 12 values. d 12/244, 0, 1, 2, 3, 4 of the four possibilities to take the remainder (also re-rounded), and 0 correspond to the base stations BTS1 and BTS2 transmitted signals are formed at different reception point, These four phase differences of 1, 2, and 3 chips each correspond to a hyperbolic band with a width of about 244 meters. When the result is 0, it meets the condition of being subject to large adjacent channel interference. Without forward delay control, mobile station MS1 is subject to greater interference from base station BTS2. When the result is the other three values, mobile station MS1 is subject to base station interference. The interference of BTS2 is small, at this time the mobile station MS 1 It is located in an area other than the area represented by the hyperbola in FIG. 6. When the result is 2, the mobile station MS1 is located near the middle of two adjacent hyperbola.
- Mod (Mod (d 12/244 , 4) + (ee 2), 4) is meant to base station BTS2 transmits the mobile station MS2 1 ⁇ 2 number reaches the mobile station MS1, mobile station MS1 and exactly the phase difference between the code channels is a multiple of 4 chips, mobile station MS1 will form large interference; if Mod (Mod (d 12/244 , 4) + (e factory e 2), 4) results
- Mod (Mod (d 12/244 , 4) + (e factory e 2), 4) results
- the signal sent to the mobile station MS2 reaches the mobile station MS1, the interference to the mobile station MS1 is small. Therefore, as can be seen from Table 2,
- Mod (d 12/244, 4 ) is equal to 0, whether the mobile station MS1 how phase delay, the base station BTS2 transmits the signal will be subject to the delay> ⁇ large interference code channels with the purpose of;
- Mod (d 12/244, 4 ) is equal to 1, as long as the phase delay of the mobile station MS1 + 1, regardless of the signal transmitted from the base station BTS2 of each code channel delay how the mobile station MS1 would avoid adjacent channel interference Larger case
- Mod (d 12/244, 4 ) is equal to 2, as long as the phase delay of the mobile station MS1 is 0, regardless of the signal transmitted from the base station BTS2 of each code channel delay how the mobile station MS1 would avoid adjacent channel interference than Big situation
- Mod (d 12/244, 4 ) is equal to 3, as long as the phase delay of the mobile station MS1 -1, regardless of the signal transmitted from the base station BTS2 of each code channel delay how the mobile station MS1 would avoid adjacent channel interference Bigger case.
- the positions of all mobile stations can be determined, that is, the distance between the position where the mobile station is located and the large adjacent channel interference zone in FIG. 6 can be accurately determined according to the positioning information, and the situation when performing forward delay control,
- the value can be taken according to Table 3. At this time, the possibility that the mobile station is subject to a large adjacent channel interference (ACI) is reduced.
- ACI adjacent channel interference
- a channel in cell C1 may choose to advance a chip ahead of time for the neighboring base station BTS2 to avoid greater interference, and for the neighboring base station BTS3, it is required to lag by one chip.
- BTS1, BTS2, and BTS3 there is a mobile station MS1 in cell C1. Let BTS1, BTS2, and BTS 3 reach the mobile station MSI distances are ⁇ , r 2 and r 3 , and
- 61 is a forward channel delay amount used by the MSI, and e 2 and e 3 represent delay amounts of a forward channel in the cells BTS2 and BTS3, respectively; the base stations BTS 1, BTS2, and BTS 3 send signals at the same time. According to the previous derivation, we can get
- Mod (d 12/244, 4 ) and Mod (d 13 / 244,4) similarly respectively 0, 1, 2, 3 may be four kinds of values, provided e 2, e 3, respectively, have the same - 1, 0, 1 Three values are possible, each of which is independent. There are 432 combinations of the five variables. Considering the combination of all the values that meet the conditions of the adjacent channel interference UCI) interference, Table 4 will be obtained.
- Table 6b Forward delay control, Mod (d 12 , 4) and Mod (d 13 , 4)
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN01815250.3A CN1211967C (zh) | 2001-07-20 | 2001-07-20 | 降低cdma通信系统相邻信道干扰的方法 |
PCT/CN2001/001187 WO2003009505A1 (fr) | 2001-07-20 | 2001-07-20 | Procede permettant la reduction de brouillage dans des voies adjacentes dans un systeme de communications a acces multiple par repartition de code (amrc) |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/CN2001/001187 WO2003009505A1 (fr) | 2001-07-20 | 2001-07-20 | Procede permettant la reduction de brouillage dans des voies adjacentes dans un systeme de communications a acces multiple par repartition de code (amrc) |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2003009505A1 true WO2003009505A1 (fr) | 2003-01-30 |
Family
ID=4574833
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2001/001187 WO2003009505A1 (fr) | 2001-07-20 | 2001-07-20 | Procede permettant la reduction de brouillage dans des voies adjacentes dans un systeme de communications a acces multiple par repartition de code (amrc) |
Country Status (2)
Country | Link |
---|---|
CN (1) | CN1211967C (zh) |
WO (1) | WO2003009505A1 (zh) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1134205A (zh) * | 1993-10-27 | 1996-10-23 | 诺基亚电信公司 | 消除多址干扰的方法和移动站 |
US5584057A (en) * | 1993-04-29 | 1996-12-10 | Ericsson Inc. | Use of diversity transmission to relax adjacent channel requirements in mobile telephone systems |
-
2001
- 2001-07-20 CN CN01815250.3A patent/CN1211967C/zh not_active Expired - Fee Related
- 2001-07-20 WO PCT/CN2001/001187 patent/WO2003009505A1/zh active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5584057A (en) * | 1993-04-29 | 1996-12-10 | Ericsson Inc. | Use of diversity transmission to relax adjacent channel requirements in mobile telephone systems |
CN1134205A (zh) * | 1993-10-27 | 1996-10-23 | 诺基亚电信公司 | 消除多址干扰的方法和移动站 |
Also Published As
Publication number | Publication date |
---|---|
CN1211967C (zh) | 2005-07-20 |
CN1452822A (zh) | 2003-10-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Salmasi et al. | On the system design aspects of code division multiple access (CDMA) applied to digital cellular and personal communications networks | |
JP3848253B2 (ja) | 移動通信システムにおけるアップリンク同期伝送方式ハンドオーバ及びアップリンク同期伝送方式の転換を遂行する方法 | |
US7031282B2 (en) | Method and apparatus for providing orthogonal spot beams, sectors, and picocells | |
KR101547790B1 (ko) | Cell_fach 및 유휴 모드에서의 무선 링크 동기화 및 전력 제어를 위한 방법 및 장치 | |
AU685523B2 (en) | Method for eliminating mutliple-access interference and a mobile station | |
US7480271B2 (en) | Method for reducing multi-cell interferences in wireless communications | |
US20060050662A1 (en) | Uplink interference cancellation | |
US7012948B2 (en) | Method for assigning codes in uplink of synchronous wireless telecommunication system | |
KR20060009350A (ko) | 시분할 듀플렉스 코드 분할 다중 액세스(tdd-cdma)네트워크에서 소프트 핸드오버 및 소프터 핸드오버 방법 | |
WO1994010766A1 (en) | Code division multiplex access mobile communication system | |
EP1733489A1 (en) | Method and apparatus for joint detection in downlink tdd cdma | |
CN110213804B (zh) | Nr非授权下行场景下的一种全向和方向lbt动态切换方法 | |
KR100760479B1 (ko) | 같은 주파수 밴드폭에서 두개의 cdma 시스템을오버레잉하는 방법 및 장치 | |
JP2002509240A (ja) | Cdma移動通信システムにおいて、移動ターミナルの位置を決定するための方法およびシステム | |
JP3069603B2 (ja) | 移動通信システムでの逆方向同期設定方法及びそれを利用した逆方向同期式伝送方法 | |
JP3865212B2 (ja) | 送信電力設定方法、移動通信システム及び基地局 | |
JP2001309425A (ja) | Cdma移動通信システム | |
GB2391427A (en) | A communication system and method of allocating resource | |
WO2003009505A1 (fr) | Procede permettant la reduction de brouillage dans des voies adjacentes dans un systeme de communications a acces multiple par repartition de code (amrc) | |
KR20010021098A (ko) | 씨디엠에이 기지국 장치, 및 씨디엠에이 이동 통신 시스템 | |
WO2009079956A1 (fr) | Procédé et système de détection de source de brouillage de liaison descendante, et dispositif associé | |
JP2008278525A (ja) | スペクトラム拡散通信システム及び該システムを構成する送信機及び受信機 | |
JP2004088696A (ja) | 移動無線端末装置 | |
KR100833064B1 (ko) | Td-scdma 시스템의 동기 제어방법 및 이에 적용되는 장치 | |
JP3777845B2 (ja) | スペクトラム拡散通信システム及び該システムを構成する送信機及び受信機 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 018152503 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
122 | Ep: pct application non-entry in european phase | ||
NENP | Non-entry into the national phase |
Ref country code: JP |