TW574797B - Transmission power control method and system for CDMA communication system - Google Patents

Description

574797 Case No. 91102157 Revised 玖, Description of the invention: '[Technical Field to which the Invention belongs] The present invention relates to a code division multiple access system, and more particularly to a multimedia system. Direct-sequence code division multiplexing access system uses a completely decentralized upload power control method. The present invention relates to a code division multiple access system, and more particularly relates to a direct code sequence (direct_sequence) of a multimedia code division multiple access system, using a fully distributed upload power control method. [Previous technology] In a CDMA multiple access system, a plurality of mobile users share the same frequency band to communicate with a single base station. Therefore, for example, if mobile station A and mobile station B transmit the modulated sine wave signal to the base station, the signal transmitted by mobile station 0 (received without receiving payment) will interfere with the transmission of mobile station A. The signal (may not be received), and communication between mobile station a and the base station has been established. The degree of this interference depends on the number (not necessarily received) received by the base station. If the level of interference increases to a certain level, communication between the mobile station and the base station will become impossible. If the transmission power of each mobile station can be controlled to always limit the signal level at the base station to a minimum and accepted power, then the maximum channel capacity for this communication by the base station will be possible. The farther the transmission power is away from the minimum required and acceptable power, the less channel capacity the base station can communicate with. 5 When the code division multiplexed access / t positive IS-95 transmission power method has been adopted, the system ’s transmission power control is unified, that is, adopted by North America. The number is described in ΤΙΑ / Ι · Series 95—Standard system. The response due to the two-way communication in the hive rate method will be described below. Meyer, S, and sound π are required for you, and you need to be first, that is, one uploaded :: 2: The mobile channel is used for the base station. The line: =, the uploaded mobile channel system-a kind of Data is transmitted by action = channel, and the mobile channel to be transmitted is a channel that transmits data from the base port to the mobile station. ", Figure 1 shows its structure of a mobile communication network. A public telephone exchange network is connected to a fixed terminal 200, such as-电 居 # 动 通信 网络 2G2. The mobile communication network The system is connected to a plurality of base stations 2G3a, 2㈣, and, and each base station 203 communicates with the mobile station 402a, 204b, and 402 in the cell it serves. FIG. 2 shows a communication system diagram of one-code multiplexed access. The system includes a mobile station 10, a base station 20, and an upload (reverse link) 30. The upload system indicates An electromagnetic wave communication link channel from the mobile station 10 to the base station 20, and a down-pass (forward chain) 40, which indicates the electromagnetic wave communication link channel from the base station 20 to the mobile station 10. The method of controlling the level of interference in a communication system with code division multiplexing is by power control, that is, when the power is transmitted from the mobile station 10 to the base station 20 (upload, reverse chain) or the power is transmitted from the base When station 20 is transmitted to mobile station at 10 o'clock (downlink, forward chain), all are controlled Or variable 574797 r *, v · 91102157 said date correction. Because the so-called "near / far problem ,,, power control upload (reverse strand) based 'is 2. This problem occurs when:-the mobile station is close-the base station will experience or be crossed to a relatively low power propagation loss, so the base station will see-a fairly high level of power from the mobile station, and vice versa-the mobile station Moving away from a base station will experience or suffer a relatively high power propagation loss, so the base station will see a relatively low level of power from one of the mobile stations. The uploaded power control is used to control the approaching or distant mobile station to reduce or increase the transmission power to the base station, which is a well-known technology; 1 See US Patent No. 6 issued to Edwards et al. No. 216 〇１〇 ♦, whose title is "Upload Power Control for Fixed Wireless Access", reveals that this upload power control is used for fixed wireless access communication networks. In the present invention, a radio frequency communication upload power control system in which the distance information between an external station (outstation) and a base station is related to a channel loss, and the channel loss uses a power control algorithm, so the signal power transmission can be ° Ideally controlled. The invention provides a power control strategy that is not only suitable for all channel losses, but also for individual loss of components. The channel loss is based on the received signal power and the transmitted signal power (the signal power transmitted by the # is calculated and calculated differently by the receiving station. See the US patent number issued to Tsunehara No. 6'307'844, No. 'Its title is "Divided Code Multiplexing Access System and Transmission Power Control Method'" Uncovering-Transmission Channel Transmission Power Control Method for Mobile Communication System for Single-direction Communication: : Ground, test the data transmitted by each mobile terminal in each channel. Case No. 91102157 Correction Date and generate transmission power control signal for each uploaded AC channel; the transmission power control signal is more Transmission and general multiplex transmission power control signals are transmitted to all mobile terminals through channel sharing using general mobile terminals. Each mobile terminal obtains the terminal from the received general transmission power control signals The transmission power control signal of the uploaded AC channel is used, and the transmission power of the message packet is controlled. In addition, the 'power control planning table is centralized It depends on the nature of control. For centralized control, the base station has complete knowledge of the connection gain to determine the power adjustment of each mobile station, but for decentralized institutions, the base station Have only part of the information of the received power (such as 'signal-to-noise ratio') (localinf〇rmati〇n). Many documents have discussed the distributed power used in frequency division multiplexed access and time division multiplexed access systems The control method assumes that under the threshold of the signal-to-noise ratio of all mobile stations with the same requirements, it focuses on the convergence speed of the power control process. In IEEE Trans · On Vehicular Technology, ρ · 1424_1429, Vo1 · 49 , No. 4, July 2000, published in the paper, transmission power characteristics in the CDMA multi-access cellular mobile system. In the paper, Mr. Wu first proposed a way to extend the results of his research. In the code multiplexed access system, it is determined that the concentration is a reasonable solution for power control. In addition, he further proposed a decentralized power control algorithm. This method is used for signals with different signals. Frequency division multiple access system for multimedia direct sequence requiring threshold for noise ratio. For frequency division multiple guard access system for multimedia direct sequence with different signal to noise ratio requirement threshold, please refer to Mr. Wu The power adjustment formula of the modified power control algorithm proposed in the distributed case number 91102157 is as follows: Case number 91102157 revised in the month Pi (n + l) = cn

Pi p («) where 6 (η) is the transmission power of the i-th mobile station in the n-th iteration, and A is the minimum signal-to-noise ratio threshold of the i-th mobile station in the base station; rf0 is The signal-to-noise ratio of the i-th mobile station received in the nth iteration, c (w) is the power control factor and = in all cells

The maximum transmission power of the mobile station in CK n iterations. In each iteration, the mobile station i will adjust its power, which is the information from the base station 7i Yi. The results of numerical analysis show that the received signal to noise ratio can converge by this algorithm. However, this algorithm has a disadvantage: it is not practical for the base station to obtain the maximum power unless it is uploaded via a signal or changed in all cells. However, in order to implement the power control process mentioned in the past, the base station must know the maximum transmission power of all mobile stations in all cells: Therefore, this method is not practical for decentralized systems. Therefore, there is a need to provide a transmission power control method for a communication system with one code multiplex access. The method only needs to know part of the information at the base station, and can achieve different signals to the mobile station due to appropriate principles. Than the requirements. [Summary] Accordingly, the object of the present invention is to provide a transmission power control method for code division multiplexing access; / Case No. 91102157 Month-Day Modification System transmission power control method, especially the direct code division multiplexing of multimedia Access system. A secondary object of the present invention is to provide a transmission power control method for a code division multiplexed access system, wherein the method only needs to know part of the information at the base station and can achieve different signal and noise to the mobile station due to appropriate principles. Compared to requirements. A more important object of the present invention is to provide a transmission power control method for a code division multiplexed access system, wherein the method can not only quickly converge, but also make the transmission power within a reasonable range. In order to achieve the above object, the present invention provides a transmission power control system for a code division multiplexing access system, particularly a direct sequence code division multiplexing access system for multimedia. The code division multiple access system communicates between a base station and a plurality of mobile stations. The transmission power control method includes the following steps. First, the plurality of mobile stations transmit an uplink power to the base station. In the second step, the base station receives and measures the uplink power, where the uplink power comes from one of each of a plurality of mobile stations and has different signal-to-noise ratio requirements for the base station. In the third step, a device uses an iterative algorithm to obtain a convergent transmission power. The iterative algorithm indicates that the N + 1th transmission power of the first mobile station is equal to a convergence factor multiplied by the Nth transmission power of the first mobile station, where the convergence factor system in the nth iteration It is equal to one of the power convergence factors # in the nth iteration divided by one to determine the factor ρ (η) in the nth iteration. And the determining factor ρ (η) in the nth iteration is equal to the signal-to-noise ratio of the i-th mobile station received in the n-th iteration, divided by the base station for the i-th Line 574797, case number 91102157, requires the signal to noise ratio threshold (8). According to a feature of a transmission power control method of the present invention, the iterative algorithm is developed at the η-th money generation step—the step is selected, and the power convergence factor ^ is similar to the sub-P in the η-th iteration. (η), that is, c (w) «One of the power convergence factors of a transmission power control method according to the present invention is to receive the partial information from the target cell 'and the signal-to-noise ratio gate :: Xunbi acupoint means that the value of (^) among all base stations in this cell, the minimum value of $ among all base stations in this cell r («), or v (« ), ($-). One of the advantages of the transmission power control method of the present invention is that the method only needs to be known at the base station: # 讯 ’and can be regarded as an appropriate principle. Principle) The mobile station meets different signal-to-noise ratio requirements. One of the advantages of the transmission power control method of the present invention is that the method can not only converge quickly, but also make the transmission power within a reasonable range. Other features and advantages of the present invention will be apparent from the following detailed description, the accompanying drawings, and the scope of the patents as defined. 11

5747971 Ο- π · I ϊ, 丨:.; J I ./4 '/! Case No. 91102157 Revised in January [Simplified Illustration] In order to make the benefits and advantages of the present invention, those skilled in the art can understand the related technology To understand more clearly, the following description will be described in detail with the accompanying drawings, wherein: FIG. 1 is a structural diagram of a mobile communication network. Figure 2 is a representation of the prior art of a frequency division multiplexed access system. Fig. 3a is a diagram showing a frequency division multiplexing access system according to an embodiment of the present invention. Figure 3b is a frequency division multiplexing communication system showing 19 cells in the present invention. Fig. 4 is a graph of the convergence rate and different M values produced according to the present invention. The results are the maximum, minimum, and average factors of the parts used. Fig. 5 is a level diagram of transmission power variation according to the present invention. The result is that different power convergence factors are used at M = 7. Fig. 6 is a level diagram of transmission power variation according to the present invention. The result is that different power convergence factors are used at M = 9. [Schematic description] 10 mobile stations 20 base stations 20 30 — upload (reverse chain) 40 — download (forward chain) 100 base stations 110, 120, 130, 140, 150 mobile station 200 — public switched telephone network 201 —Fixed terminal 202 —Mobile communication network 12 574797 ~ year

Case No. 91102157 203a, 203b base station year, month, day, amendment 204a, 204b mobile station [implementation]

Although the present invention is allowed to be carried out in various embodiments, it is shown in the figure and a specific embodiment of the present invention will be described later. It should be understood that what is disclosed should not be construed as an illustration of the present invention, but is not intended to limit the present invention to the specific embodiments shown. It should be further understood that the title of this section, "Detailed Description of the Invention, usually refers to the requirements of the US Patent and Trademark Office," and is not necessarily included or delivered to limit the subject matter disclosed and the scope of the patents here. Figure 3a is a diagram showing a frequency division multiplexing input connection system according to an embodiment of the present invention.

Figure 3a shows a plurality of mobile stations no, 120, 130, 140, and 150 along with an example base station 100. The above includes a cellular system. It should be noted that there will be N mobile stations in this system. Here, the mobile station I (1 = < I = < N) indicates an arbitrary mobile station. Arrow ill-112 defines the possible communication between base station 100 and mobile station 110. Similarly, arrows 121-122, 131-132, 141-142, and 151-152 define the possible communications between base station 100 and mobile station 120, 130, 140, and 150, respectively. The mobile stations 110, 120, 130, 140 and 150 transmit upload power to the base station 100. The base station 100 receives and measures the power, where the power comes from one of each of the plurality of mobile stations and has different signal-to-noise ratio requirements for the base station. The base station 100 adopts a modified variant method to converge the power from a plurality of mobile stations, and the base station 100 calculates and adjusts the power by a power adjustment factor, where the power is 13 5ir ^ m The 91102157 correction rate comes from one of each of the multiple mobile stations. The received signal-to-noise ratio in the base station is from the i-th mobile station system: W⑷ μ where G; 1 is the channel gain from mobile station j to base station 1, f is other cell interference factors, and M is The number of mobile stations in the cell. It is noteworthy that whether A is reasonable or unreasonable depends strongly on the received power from other stations (ie, Gyif) or the required A (for μm) and M values. Because in most cases, under the principle of fairness, it can be reasonably required

And lim ^^ p \ n) = p for all i. This means that all signal-to-noise ratio requirements {βί} are reasonable when P 2 1. On the other hand, if P < 1 and the degradation details of the feature are allowed, the removal methods will be used. From the above discussion, we can know that > («+ 0 in) _, ⑻ n rU) π (>(°); = 〇 Pi In order to obtain a convergent transmission power, the choice seems to be a

Pj good way. Therefore, the method according to the embodiment of the present invention is provided as follows: 1. The first method uses a partial maximum factor of 14 574797: Case No. 91102157 Modified 'Order one dagger ^^) ^, that is, the power convergence factor ( f) all in this cell

Pj " y The maximum number of base stations. 2. The second method uses a partial minimum factor order, that is, the power convergence factor (f) is the minimum value of all base stations in this cell. y («) 3. The third method uses a partial average factor to make c ^ = (^-) flVg, that is, the power spring Pj convergence factor ($-) is the average of all base stations in this cell. Referring to Fig. 3b, Fig. 3b is a diagram of a frequency division multiplexed incoming communication system showing 19 cells in the present invention. The central cell line surrounded by 18 other hexagonal cells is the target cell. Assume that there are M mobile stations evenly distributed in each cell and have different signal-to-noise ratio threshold requirements {Bi} = {-15, -14, ..., -15+ (Μ-1)}. The initial transmission power of each mobile station is randomly distributed and exceeds 30dB. Note * Note that this value is only a proportion. The actual transmission power must be determined by the system at the time, so it is not in the scope of this patent. A large-scale attenuation propagation model is considered for the winding process. It is known from experience that the large proportional attenuation gain system is often expressed as η_

L {t) = k ^ Y ~ aWQ, where k is a constant, r is the distance, α is the path loss index and 7 is a uniformly distributed random variable, which has a zero mean and a variability of 4. 15 574797 Case No. 91102157 Amendment In the simulation we take ^ and ^. The large-scale attenuation propagation model is assumed to be fixed for any particular actor in the per-calculation process, but variable for each mobile user. Referring to Fig. 4 'is a graph of the convergence rate / different M value according to the present invention, and the results are expressed in terms of the maximum, minimum, and average factors. Note that the power convergence factor will not affect the received signal to noise ratio. For the proposed method, we can get the same graph. It can be seen from the figure that β is converged in less than 5 iterative steps, and the system characteristics (signal to noise ratio) require that after M > 9, it will be unrecoverable, refer to Figure 5 and Figure 6 ^ Power variation chart is shown. The result is the same power convergence factor as M = 7 and μ = 9 ^. The power convergence factor is set to the range of the transmission power. Although the two-knife floor shirt of the present invention can provide almost the same ㈣ΓΓΓ factor in the rate of convergence, it is clear that when the material is maximized, 彳 j is cleared and the potential is reduced. Therefore, it is known that the use part will fall strictly between these two results. Corridor power and watts, such as m㈣transmission power, have units of 单位 u (such as watts and watts) (this indicates that we can compare the steady-state transmission power of the power of any watt and the initial transmission power to z =) 'The dynamic range requirement of the power of the transmission wheel of the approximate moving platform. According to this view: will: less line algorithm using a part of the average factor will be a better one. Therefore, from the above knowledge, we can know that most of the amendments and changes can be realized, and 16 574797:, Case No. 91102157, the amendment will not depart from the original purpose of this creation and the concept of innovation. It should be understood that the specific embodiments shown are not intended or meant to limit the invention; the disclosed are intended to encompass the scope of the appended patent and all amendments will fall within the scope of the patent.

17

Claims (1)

574797 r * f,.. '-Bu ... Yi ..--.). 4 Case No. 91102157 Amendment and Patent Application Scope: 1. A transmission power control for code division multiplexed access system The method includes the following steps: transmitting an uplink power, the uplink power is from a plurality of mobile stations to a base station; receiving and measuring the uplink power, wherein the uplink power is from the plurality of mobile stations One requires a different signal-to-noise ratio for the base station, and an iterative algorithm is used to obtain a convergent transmission power. 2. The transmission power control method according to item 1 of the scope of patent application, wherein the iterative algorithm indicates that the N + 1th transmission power of the first mobile station is equal to a convergence factor multiplied by the Nth of the first mobile station Transmission power, where the convergence factor in the nth iteration is equal to one of the power convergence factors C (w) in the nth iteration divided by one of the determination factors ρ (η) in the nth iteration. 3. The transmission power control method according to item 1 of the scope of the patent application, wherein the determination factor ρ (η) in the n-th iteration is equal to the signal pair of the i-th mobile station received in the n-th iteration Noise ratio (#)) divided by the signal-to-noise ratio requirement (A) for the signal of the i-th mobile station in the base station. 4. The transmission power control method according to item 3 of the scope of patent application, wherein the iterative algorithm further selects the power convergence factor β in the nth iteration to be similar to that in the nth iteration The determining factor ρ⑻, that is, 淖)). 18 ~ sharp 91102157 + aa red 5. The transmission power control method according to item 1 of the patent application scope, wherein the power convergence factor is part of the signal-to-noise ratio information received by the target cell and the signal pair Noise ratio is determined by threshold requirements. 6. The transmission power control method according to item 5 of the scope of patent application, wherein the power r («) rate convergence factor is the maximum value (¥) among all base stations in this cell. 7. The transmission power control method according to item 5 of the scope of patent application, wherein the power y («) rate convergence factor is the minimum value of (^-) among all base stations in this cell. 8. The transmission power control method according to item 5 of the scope of patent application, wherein the power r⑷ rate convergence factor is an average value of (^-) among all base stations in the cell.口 j 9. The transmission power control method according to item 1 of the scope of the patent application, wherein the algorithm is simulated under the following conditions: Assume that M mobile stations are evenly distributed in each cell and have different signal pairs. Noise ratio threshold requirements; and use a large proportion of the attenuation propagation model in the on-chain process. 10. The transmission power control method according to item 9 of the scope of the patent application, wherein the large-scale attenuation propagation model is assumed to be fixed for any particular actor in each calculation process, but variable for each mobile user. 11. The transmission power control method according to item 1 of the scope of patent application, wherein the multiplexed communication system is a direct sequence multiplexed communication system. 12. —A transmission power control system for a code division multiplexing access system. The system includes: year and month S correction: set to 'used to transmit an uplink power automatic station to a base station; The on-chain power is set by a plurality of units for receiving and the rate is from the plurality of mobile stations, and the on-chain power, where the signal of the on-chain work requires a noise-to-noise ratio; < The base station has different placements to use an iterative, current rate. \ Different method to obtain a convergent transmission work 13. According to the twelfth generation algorithm in the scope of the patent application, the first round power control system is shown, where this is equal to a convergence factor multiplied by the first motion. The N + 1th transmission power is the Nth transmission power of the mobile station in the nth iteration, and one of the power convergence factors ^ convergence factor is equal to the nth iteration factor / 3 (η). In one of the nth iterations, I decided that the decision in the nth iteration of the 13th iteration of the patent scope was based on the power control system, in which the received sub- ^) is equal to the η-th For the i-th action in the platform in the iteration, ▲ Λ = the noise ratio (rf0) divided by the base U. According to the patent application scope No. 14: alum to noise ratio threshold U). The generation algorithm is in the first transmission power control system, where the power convergence factor ⑻a is further advanced-the η iteration is determined by the constant factor ρ (η), which is similar to that of P in the Qian generation. 'That is c% Pi〇 ^ (t Ό • according to the patent application No. 13 of the scope of the wheel power control system, where the 20 574797.: 肊 m': '., 丨 --.-'; two: ^ 乂 丨 Case No. 91102157 Revised Power Convergence Factor is determined by part of the signal-to-noise ratio information received in the target cell and the signal-to-noise ratio threshold requirements. 17. According to the application The transmission power control system according to item 16 of the patent, wherein the y⑻ power convergence factor is the maximum Pj value among all base stations in this cell. 18. The transmission power control system according to item 16 of the application, wherein the power convergence factor The minimum value of ($) among all base stations in this cell. 19. The transmission power control system according to item 16 of the patent application scope, wherein the y («) power convergence factor is the average of all base stations in this cell. Pj value 20. The transmission power control system according to item 13 of the patent application scope, wherein the algorithm is simulated under the following conditions: Assume that M mobile stations are evenly distributed in each cell and have a different signal-to-noise ratio Threshold requirements; and the use of a large-scale attenuation propagation model for the on-chain process. 21. The transmission power control system according to item 20 of the patent application scope, wherein the large-scale attenuation propagation model assumes any specific action in each calculation process It is fixed, but it is variable for each mobile user. 22. The transmission power control system according to item 13 of the scope of patent application, wherein the communication system of the multiplexed access is a direct sequence of multiplexed access. Access 21 574797________ Satoshi, Amendment 丨 Supplement 丨 Case No. 91102157 Month-Day Amendment _-ri r I 丨 _ 丨 I-η " II—. As a noisy communication system. The base station of the system is received at the code division multiplexing station. The base station includes: a set for receiving and measuring an uplink power, wherein the uplink power is from a plurality of mobile stations ―And the signal to noise ratio requirement of the base station; The device is used to make-iterative method to get 4 number of transmission power, apply for 23 base stations, where the iteration can not show the brother. The first transmission power of the mobile station is equal to the ^ th transmission power of the mobile station, and the convergence factor in the iteration of ϊ is equal to the factor n at the nth iteration. Μ 一 is in the nth iteration No.—Decision 25. According to the United States and China in the scope of the 24th patent application, the determinant factor 〆) is the same as the first action received in the heterogeneous iteration of the signal of the mobile station in the iteration of the nth iteration Taiwan's news Shanghai (屮) divided by the base station for 26. According to the scope of patent application requirements 申请. : Going further in the nth iteration. The second iteration, where the iteration is also called 'ρΆ. (Determining factor ρ also applies for the base station No. 4 of the patent scope of the country's fourth base station, Bazhong Power Convergence Factor 22 27 574797 Case No. 91102157 Amendment The daughter is determined by the partial signal-to-noise ratio information received in the target cell and the signal-to-noise ratio threshold requirements. 28. The base station according to item 27 of the scope of patent application, wherein the power convergence factor is the maximum value of (^) among all base stations in this cell. 29. The base station according to item 27 of the scope of patent application, wherein the power convergence factor y⑷ is the minimum (+) of all base stations in this cell. P j 30. The base station according to item 27 of the scope of patent application, wherein the power convergence factor y («) is an average value of all base stations (q ~) in this cell. 31. The base station according to item 23 of the scope of patent application, in which the algorithm is simulated under the following conditions: Assume that M mobile stations are evenly distributed in each cell and have different signal-to-noise ratio thresholds. Requirements; and use a large proportion of the attenuation propagation model for the on-chain process. 32. The base station according to item 31 of the scope of patent application, wherein the large-scale attenuation 豢 propagation model is assumed to be fixed for any particular actor in each calculation process, but variable for each mobile user. 33. The base station according to item 23 of the scope of patent application, wherein the communication system of the multiplexed multiple access is a direct sequence communication system of the multiplexed multiple access. twenty three