KR100860534B1 - Orthogonal code hopping multiplexing system employing adaptive beamforming array antenna - Google Patents

Abstract

The present invention relates to a method and apparatus for applying an adaptive beamforming array antenna using a beamforming technique as an intelligent antenna in a forward link of a code division multiple access system using an orthogonal code hopping multiplexing scheme. A first communication station transmitter apparatus according to the present invention includes a hop pattern generator for generating an orthogonal code hopping pattern corresponding to a forward link communication channel to each second communication station, and an orthogonal code to be assigned to each symbol period of an orthogonal code hopping pattern. An orthogonal code generation unit, a band spreader for generating a transmission signal by spreading the transmission symbol to each second communication station using the generated orthogonal code, and based on the arrival angle information of each second communication station that is periodically measured An adaptive beamforming array antenna unit for generating a weight vector corresponding to the forward link communication channel to the second communication station and applying the weight vector to the spread spectrum transmission signal and transmitting the weight vector to each second communication station through the plurality of beamforming antennas. It is characterized by including. According to the present invention, by applying the spatial filtering provided by the adaptive beamforming array antenna technique to an orthogonal code hopping multiplexing scheme, transmission quality degradation due to symbol collision and symbol puncturing can be effectively prevented.

Orthogonal code hopping multiplexing, adaptive beamforming array antenna, angle of arrival, group width.

Description

ORTHOGONAL CODE HOPPING MULTIPLEXING SYSTEM EMPLOYING ADAPTIVE BEAMFORMING ARRAY ANTENNA}

1A and 1B are block diagrams illustrating a Quadrature Phase Shift Keying (QPSK) spreading / despreading and modulation / demodulation unit of a conventional orthogonal code hopping multiplexing scheme.

FIG. 2 is a diagram illustrating a collision symbol control method when collision detection and collision between two different channels of a controller are detected in a conventional binary phase shift keying (BPSK) system of a conventional orthogonal code hopping multiplexing scheme.

3 is a block diagram illustrating a structure of a transmitter of a conventional adaptive beamforming array antenna using phased array antennas which is a type of intelligent antenna.

4 is a diagram illustrating the operation of a conventional adaptive beamforming array antenna to support mobility of a second communication station.

5 is a block diagram illustrating a baseband processor for each forward link communication channel in an orthogonal code hopping multiplexing transmitter according to the present invention to which an adaptive beamforming array antenna is applied.

6 is a diagram conceptually illustrating a symbol collision detection process when the adaptive beamforming array antenna technique is applied to an orthogonal code hopping multiplexing scheme.

7 is a diagram conceptually illustrating the conditions of symbol collision and resulting symbol puncturing between transmission beams provided by the first communication station to the second communication stations.

8A and 8B are diagrams conceptually illustrating a group-based hopping pattern allocation method based on the angle of arrival in an orthogonal code hopping multiplexing adaptive beamforming array antenna system.

9 is a diagram conceptually illustrating a hopping pattern allocation method for each angle of arrival based subgroup proposed by the present invention.

10 is a diagram conceptually illustrating group width reduction / expansion, which is a basic operation of the adaptive group width control method.

11A and 11B are diagrams illustrating a process of performing adaptive group width control through group width reduction / expansion.

<Explanation of symbols for the main parts of the drawings>

130, 135: Spreader 146: Orthogonal Code Generator

140: jump pattern generator 542, 544: collision detection and controller

320: weight vector processor 340: weight vector summer

721, 722, 723, 724: second communication station

The present invention relates to wireless data transmission and reception of an orthogonal code hopping multiplexing method using an adaptive beamforming array antenna, and more particularly, to an orthogonal code hopping multiplexing method in a forward link of a mobile communication system of a code division multiple access method. As a technique and apparatus for applying an adaptive beamforming array antenna using a phased array antenna, and an addition for mitigating the effects of intersymbol collisions and perforation based on the characteristics of the adaptive beamforming array antenna in the application technique and apparatus. Techniques and devices.

Orthogonal Code Hopping Multiplexing (OCHM) is described in detail in Ref. 1 and Ref. 2, and in this specification, code division that is already commercialized and in service to help conceptual understanding of the multiplexing scheme. The following description is based on IS-95, which is a Code Division Multiple Access (CDMA) system.

The reference numerals used in the drawings for describing the prior art apply equally when the parts having the same function and structure are applied to the embodiments of the present invention.

1A and 1B illustrate a conventional Quadrature Phase Shift Keying (QPSK) spreading / despreading and modulation / demodulation unit of an orthogonal code hopping multiplexing scheme, and FIG. 1A illustrates an internal configuration of a spreading and modulation unit of a first communication station transmitter. . Referring to FIG. 1A, symbols subjected to channel encoding for each channel branch into an in-phase channel and a quadrature channel 110 to perform QPSK modulation (110), and signal "0" of each symbol. And " 1 " are converted into " + 1 " and " -1 ", which are physical signals actually transmitted through the signal converters 120 and 125, and then spread by an orthogonal code (130 and 135).

The orthogonal code used at this time may be allocated differently for every symbol. One of the orthogonal codes generated by the orthogonal code generator 146 is selected and assigned to each symbol by the random leap pattern generated by the hop pattern generator 140. The orthogonal codes that are applied include not only Walsh codes, but also all orthogonal codes, such as the Orthogonal Variable Spreading Factor (OVSF) code or the Orthogonal Gold code used in IMT-2000. .

Meanwhile, the collision detection and controllers 142 and 144 detect collisions between orthogonal code symbols due to random hopping patterns generated for each channel and perform appropriate processing. The collision detection and the outputs of the controllers 142 and 144 are output from the quadrature code generator 146 and multiplied by the signal passed through the signal conversion device 148 (132, 136), where symbol puncture due to intersymbol collision If necessary, it is "0", and in other cases, it is "1".

The symbols of each spread channel are amplified (150, 155) and then combined (160, 165) with a power gain value determined by power control for each channel, and then a signal conversion device (1) is used to distinguish the first communication station in a multi-cell environment. QPSK spreading modulation 170, 175 is performed by short Pseudo Noise sequences 172, 176 through 174, 178. The spread modulated signal passes through low pass filters 180 and 185, passes through carrier modulations 190, 195 and 200 that modulate to the transmission band for the IQ channel, and then sums up 210 (not shown). High power amplified through RF and then transmitted through the antenna.

FIG. 1B schematically illustrates the structure of a receiver of a second communication station corresponding to the first communication station transmitter described with reference to FIG. 1A. The signal received through the antenna is multiplied by the carrier signal (220, 225) and passed through the low pass filters 230, 235 to generate a baseband received signal. The PN columns 240 and 245 generated in synchronization with the PN sequence used for spread modulation at the transmitting side are summed in bit units with orthogonal codes generated from the hopping pattern generator 250 and the orthogonal code generator 252 synchronized with the transmitter. 254, 256, and then multiply the baseband received signal via signal conversion devices 258, 260 (262, 264). The baseband received signal, which has undergone the above process, is accumulated and despread during the transmission data symbol period (270, 275), and only the pilot channel component is extracted from the orthogonal code symbol assigned to the pilot channel to estimate the transmission channel (280). The phase distortion is corrected using the in phase distortion value (290).

FIG. 2 is a diagram illustrating collision between two different channels in a collision detection and controller of a BPSK orthogonal code hopping multiplexing system corresponding to the collision detection and controllers 142 and 144 in the QPSK scheme of FIG. 1A. If a collision is detected, it is a conceptual diagram illustrating a control method for a collision symbol.

2, the downlink channel from the first communication station 210 to the second communication stations #a 221 and #b 222 is the same in any symbol period by random leap with both active. When orthogonal codes are used, the collision detection and controller compares the symbol code values on the forward channels of the two second communication stations #a 221 and #b 222. If the two symbol code values are the same, the symbols of the two second communication stations 221 and 222 are summed, resulting in an increase in symbol strength. This is called symbol synergy, and the controller output symbol value is "1". Becomes On the contrary, if the symbol code values of the two second communication stations 221 and 222 are different from each other, the controller output symbol value of each channel is set to "0", and the second communication stations #a 221 and #b 222 on the forward channel of the second communication station # 221 and 222 are different. The symbol is not transmitted, which is called symbol perforation. The purpose of symbol puncturing is to avoid error amplification of symbol estimation in the channel decoding process of the receiver, and the loss of transmit energy caused by arbitrary symbol puncturing may be compensated for by adjusting transmit power of another symbol. This control scheme for inter-symbol collision is applied to the collision detection and controllers 135 and 136 of FIG. 1A in the light of the fact that in the case of FIG. 1A, a branching operation is performed on the IQ channel for a complex signal after QPSK modulation. have.

FIG. 3 is a structural diagram for conceptually explaining a structure of a transmitter of an adaptive beamforming array antenna (ABAA) using phased array antennas as a conventional technology. Referring to FIG. 3, the transmission symbols of the individual forward link communication channels to each of the second communication stations located within any first communication station service area are subjected to baseband processing and then through the user beamformer 310 to the phased array antenna. A specific phase shift is performed for each of the parts 370, 372, and 374 to branch.

The weight vector processors 320, 322, and 324 included in the user beamformer 310 receive the transmission symbols for each channel, and multiply the specific phase shift coefficient and the power gain for each antenna. The parameters multiplied by the transmission symbols for each channel are determined with reference to beamforming-related phase information and power information updated by the forward link weight vector controller 330. More specifically, the forward link weight vector controller 330 may include angle-of-arrival (AoA) information obtained from a reverse channel received signal of an arbitrary second communication station and power control information received in a closed loop power control process. It receives the input periodically, and generates the transmit power value of the transmission channel related to the size of the transmission beam and the phase shift coefficient for each antenna related to the beam direction when forming the user beam for symbol transmission to the second communication station, the weight vector processor of the corresponding channel Forwarded to (320, 322, 324). In most cases, the weight vector operation based on the output information of the forward link weight vector controller 330 is implemented by matrix operation. The user channel signals branched to the phased array antennas 370, 372, and 374 through weight vector operations are summed for each antenna through the weight vector summer 340 to form an output signal for each transmission antenna. The output signal for each transmit antenna is transmitted through the transmit antennas 370, 372, and 374 through the carrier modulators 350, 352, and 354 and the wireless processors 360, 362, and 364.

Adaptive beamforming array antennas are used for the formation of transmit and receive beams. Given the complexity of the implementation, it is common for an adaptive beamforming array antenna to be operated in a first communication station, so that in a forward link from the first communication station to the second communication station, a transmission beamforming technique is employed, and from the second communication station to the first communication station. Receive beamforming is applied to the reverse link. In this case, using a beam-steering technique, the angle of arrival from the receiver may be measured to provide a maximum beam gain to the receiver during symbol transmission.

4 illustrates the operation of an adaptive beamforming array antenna in a forward link to support mobility of a second communication station when conceptually assuming angles of arrival information for an individual second communication station as the location direction angle of the second communication station. It is a conceptual diagram. As shown in FIG. 4, the first communication station 410 obtains the maximum transmit beam gain through the beamforming technique for the second communication station #a 420 and the second communication station #b 430 at any time t_ref. Provide a user beam. When the second communication stations 420 and 430 move for a time t_1 from the reference time t_ref, the first communication station 410 sets the angle of arrival (location) of the individual second communication stations 420 and 430 over the reverse link. It measures and updates the weight vector of each channel with this information. The updated weight vector is computed for that channel so that the maximum beam gain directivity angle on the transmission beam pattern is adjusted to the angle of arrival (position) of the second communication station 420, 430 at any measurement point. This is called beam tracking. The first communication station 410 periodically applies a beam tracking process to continuously provide the maximum beam gain to the individual second communication stations 420 and 430 even when the second communication stations 420 and 430 move.

Accordingly, the present specification proposes a new technique capable of efficiently performing forward channel transmission to a plurality of second communication stations by applying an adaptive beamforming array antenna scheme to a conventional orthogonal code hopping multiplexing scheme.

(references)

Reference 1: Republic of Korea Patent Publication No. 2000-0029400

Reference 2: Korean Laid-Open Patent Publication No. 2004-0773635

In the orthogonal code hopping multiplexing scheme, by assigning a random hopping pattern for each channel, symbol collisions occur when symbols of a plurality of channels are spread to the same orthogonal code in an arbitrary symbol interval. In this case, as described above with reference to FIG. Similarly, a control method called symbol synergy / puncture method is applied to collision symbols. However, in the case of symbol synergy and symbol puncturing during the puncturing, the energy loss of the corresponding symbols is generated by turning off the transmission power of the collision symbols. When symbol puncturing occurs frequently due to collisions between user symbols, the symbol transmission energy loss caused by the symbol transmission energy deteriorates the decoding performance during channel decoding at the receiver and maintains the error rate of an arbitrary transmission frame. This increases the ratio of bit energy to noise energy (required received Eb / No).

The present invention provides an adaptive beamforming array antenna scheme in a situation where symbol collisions between channels described above occur in an orthogonal code hopping multiplexing scheme, which is a type of multiplexing scheme in a forward link of a mobile communication system using a code division multiple access scheme. Its purpose is to dramatically reduce the occurrence of symbol collisions and perforations through the spatial filtering capability provided by. This also mitigates signal quality deterioration in the radio section caused by inter-symbol collisions, thereby ultimately improving the quality of the received signal when the orthogonal code hopping multiplexing scheme is applied, and the user capacity in any first communication station region. The purpose is to simultaneously increase the channel capacity for a limited first station transmit power.

In order to achieve the above object, the present invention applies a spatial filtering function provided by an adaptive beamforming array antenna to a spatial distribution of second communication stations that generate symbol collisions in an orthogonal code hopping multiplexing scheme, whereby It is characterized by reducing the occurrence of symbol puncture at source. In addition, the present invention reduces the degradation of channel decoding performance due to the reuse of orthogonal codes and maximizes the performance improvement effect by proposing additional techniques and devices that further increase the performance of symbol collision and puncturing of the antenna scheme. have.

In addition, the present invention considers that the adaptive beamforming array antenna technology is already in the commercialization stage, the number of forward link communication channels provided through any fixed beam generated in the first communication station is a constant value (the number of available orthogonal codes). And a new hop pattern assignment scheme that assigns an orthogonal code hopping pattern to eliminate symbol collisions and puncturing between communication channels, if less than several times, to maintain optimal link performance for any number of forward link communication channels. There is a characteristic.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings for describing the embodiments of the present invention, the same reference numerals are applied to parts having the same structure and function as those included in the prior art drawings. The following description of the present invention focuses on the parts that need to be changed or added to the prior art.

5 illustrates an internal configuration of the baseband processing unit for each forward link communication channel in the first communication station transmitter according to the present invention. Referring to FIG. 5, an arbitrary user symbol is branched into an in-phase and quadrature-phase signal (110) and passed through a signal converter (120, 125) to an orthogonal code. (130, 135). At this time, the orthogonal code used is obtained by using the orthogonal code generator 146 and the beam-specific user channel hopping pattern generator 540 and the orthogonal code generator 146 which provide orthogonal code hopping patterns for channels belonging to individual fixed beams generated from the adaptive beamforming array antenna. Is specified.

That is, the beam-specific user hopping pattern generator 540 generates an orthogonal code hopping pattern for channels belonging to each transmission beam generated by the adaptive beamforming array antenna of the first communication station, and in terms of function, the hopping pattern generator according to the prior art. Corresponds to the generator 140. On the other hand, orthogonal code generator 146 is configured to generate an orthogonal code assigned to each symbol time of the generated orthogonal code hopping pattern. For reference, examples of orthogonal codes applicable to the present invention include Quasi-Orthogonal Code of cdma2000 and Multi-Scrambling Code of Wideband Code Division Multiple Access (W-CDMA) system among IMT-2000 system standards. Generating techniques include an orthogonal gold code and a Kasami code, and the orthogonal code generator 146 may include various types of circuits for generating various other orthogonal codes, including the orthogonal code as illustrated. .

The symbol collision detection and controller 542, 544 detects symbol unit collision by comparing orthogonal codes for each channel in any symbol period of all forward link communication channels provided by the first communication station to a designated orthogonal code. For example, synergy or puncturing control may be performed by comparing symbol values between colliding symbols. The communication channels to be compared for symbol collision detection are designated by the angle of arrival information for the respective second communication station measured from the reverse link transmission signal of the second communication stations. The symbol collision detection and controller 542, 544 periodically receives the angle of arrival information of the reverse link transmission signal of the second communication station in the first communication station service area updated from the forward link weight vector controller 330.

6 conceptually illustrates a symbol collision detection process according to the present invention. The symbol collision detection and controllers 542 and 544 of the first communication station determine the angle of arrival of the second communication station corresponding to the channel for symbol collision detection for any channel in the maximum beam direction or boresight of the user beam. Set to. Based on the set maximum transmission beam direction, the angle-based range of the user beam width plus a certain amount of margin considering the angle of arrival measurement error and calculation error at the first communication station is an angle for symbol collision detection. It is set to angle range for symbol collision detection. The symbol collision detection and controller 542 and 544 designate transmission symbols of the forward link communication channels corresponding to the second communication stations having the angle of arrival value within the set angular range as compared symbols, and whether there is a collision between symbols. If the collision occurs, symbol synergy or puncturing control is performed.

The arrival angle information of the second communication stations used in the symbol collision detection process is information continuously collected to support beam tracking for user mobility in the original adaptive beamforming array antenna. No additional device, cost, and complexity are required to use angle of arrival information. The symbol collision detection and transmission symbols that have been verified as collision free at the controllers 542 and 544 or symbol punctured or synergistically controlled are spread by the orthogonal code assigned to that symbol. The spread symbols are QPSK spread modulations 170 and 175 using short PN sequences 172 and 176 for identifying the first communication station, and are then input to the user beamformer 310 to form a corresponding user transmission beam. . The transmission symbols input to the user beamformer 310 are branched for each transmit antenna in the weight vector processor 320 to obtain phase and power gain through processing with information transmitted through the forward link weight vector controller 330. Assigned. The branched signals for each transmit antenna output from the weight vector processor 320 are summed by the signals of the other channels and the transmit antennas in the weight vector summer 340, and the transmit antennas are processed through carrier modulation for each transmit antenna and radio frequency band processing. Is sent through.

FIG. 7 is an example conceptually illustrating a symbol collision between transmission beams for each second communication station provided by a first communication station transmitter having a baseband processing unit as shown in FIG. 7 shows that the second communication stations #a (721), #b (722), #c (723), and #d (724) hop between a plurality of orthogonal codes, and then all orthogonal codes OC # at any symbol transmission time point t_ref. The case where P is selected as a spreading code is illustrated. As shown in FIG. 7, since the second communication station #c 723 is not located within the symbol collision detection angle range for the transmission symbol of the second communication station #a 721, even if the same orthogonal code OC #P is used, Does not affect reception performance. Therefore, the transmission symbol of the second communication station #c 723 is excluded from the symbol collision detection comparison target of the second communication station #a 721. Accordingly, the first communication station 710 is located at #b 722 and #d 724, which are second communication stations located within the symbol collision detection angle range of the second communication station #a 721 at the time t_ref and hopping with the same orthogonal code. The symbol collision is detected, and symbol puncturing or synergy control is performed by comparing symbol values between the second communication station #a 721 and #b 722 and #d 724.

In applying the adaptive beamforming array antenna scheme to the orthogonal code hopping multiplexing scheme, the first communication station may generate a random sequence for each forward link communication channel of each second communication station and allocate a random hop pattern based thereon. Means for detecting and controlling symbol collisions provide significant performance improvements by simply selecting orthogonal codes according to random hopping patterns, but intentionally limiting the occurrence of symbol collisions and puncturing as described below. A new orthogonal code hopping pattern generation and assignment scheme may be applied. That is, a technique of generating and assigning an orthogonal code hopping pattern at a group level by grouping orthogonal code hopping patterns according to a predetermined criterion.

The transmission beams generated for each second communication station through the adaptive beamforming array antenna have a unique beam direction and size according to the position of the corresponding second communication station and perform beam tracking according to the movement of the second communication station. It has a continuous and unspecific distribution over the area. Therefore, by dividing the total angular range serviced by the first communication station into N _AHPG angle ranges by using, as a reference parameter, the angle of arrival for each second communication station periodically acquired by the first communication station from the reverse link signals from the second communication stations. Then, the entire orthogonal code hopping pattern is divided into AoA-based hopping-pattern groups (AHPGs), and a specific angle of arrival-based hopping pattern group is assigned to each divided angle range. . Next, randomly assign a hop pattern for each forward angle-based hop pattern group to a forward link communication channel to a second communication station having an arrival angle within a specific angle range.

No collision between orthogonal code hopping patterns in the angle of arrival-based hopping pattern group means that the hopping pattern is formed such that these orthogonal code hopping patterns do not spread the transmission symbol using the same orthogonal code at the same time point. A group of non-collision hopping patterns is called a collision-free hopping-pattern group (CFG). According to the above-described hopping pattern generation and allocation technique, the probability of occurrence of symbol collision and symbol puncturing is reduced. This is called an AHPG-based random group-level codeword hopping-pattern allocation (ARGHPA) scheme.

8A and 8B are specific examples of the random group level leap pattern allocation scheme for each arrival angle-based leap pattern group described above.

FIG. 8A illustrates an embodiment related to a random group level hopping pattern allocation scheme for each basic arrival angle-based hopping pattern group. FIG. According to this embodiment, when there are M forward link communication channels for the angle of arrival based hop pattern group #A in any first communication station service area and N _OC orthogonal codes can be used for the user communication channel, floor ( An orthogonal code hopping pattern is assigned to each user channel through a group of M / N _OC ) +1 collision avoidance hopping patterns. In this case, the number of collision avoidance jump pattern groups used in an arbitrary angle of arrival based jump pattern group is changed according to the increase and decrease of the number of user channels, and the N _OC orthogonal code jump patterns in the random collision avoidance jump pattern group are symbols of each other. Jump patterns with orthogonality that do not cause collisions. For reference, floor () means a floor function.

The most recent collision avoidance jump pattern group generated by a change in any number of user communication channels is all hop patterns in the group except for the situation where M% N _OC = 0 (the number of user channels is an integer multiple of the number of group hop patterns). Are not assigned to the user channel. In consideration of this, the last generated collision avoidance jump pattern group is separately defined as a recently-generated collision-free hopping-pattern group (LCFG). . The first communication station may use the frame level to minimize and equalize the frequency of symbol collisions between channels for any number of forward link communication channels that change over time in any angle-based hop pattern group or angle-based hop pattern subgroup. The angle of arrival information may be measured for each second communication station at the above cycle, and if necessary, the hop pattern may be reset. Accordingly, the number of collision avoidance jump pattern groups for each beam and the hop pattern for each channel may be adaptively changed at intervals of the frame level or more.

8B illustrates the process of generating unique jump patterns without mutual collision in any group of collision avoidance jump patterns. All collision avoidance jump pattern groups are assigned a unique random number sequence to define the hop characteristics of each collision suppression jump pattern group while sharing orthogonal code hop patterns without N _OC mutually signed collisions. The random random sequence for each group assigned to the random collision avoidance jump pattern group #S is cyclically code-switched bit by bit through the sum of the bitwise sums and the indicators of the orthogonal code hopping patterns for the transport channel belonging to the group #S. Create a jump pattern.

The leap patterns generated through the above process have a characteristic that they do not cause symbol collision by maintaining orthogonality with other leap patterns in the same group, and in the same manner as a random leap pattern allocation method with orthogonal code leap patterns in other leap pattern groups. It will cause random symbol collisions. The random group level hopping pattern allocation scheme for each arrival angle-based hopping pattern group is based on the angle of arrival-based hopping pattern group in the orthogonal code hopping multiplexing scheme using the adaptive beamforming array antenna. In an environment where a small number of forward link communication channels is required, the symbol collision probability can be greatly reduced. In particular, in an environment where the number of user channels in the angle of arrival-based hop pattern group is required to be less than the number of orthogonal codes, the existing transmission is completely excluded by the possibility that any communication channel transmission symbol in the group collides with the symbols of other user channels in the same group. The code division multiplexing scheme for assigning fixed orthogonal codes for each communication channel of (where the maximum assignable number of user channels is limited to the number of orthogonal codes) provides link performance substantially equivalent.

If the angle of arrival of a particular second communication station is located at a boundary area on an angle range of an arbitrary angle-based jump pattern group, the arrival of the vicinity of the boundary belonging to the group adjacent to the corresponding angle of arrival-based jump pattern group Channel reception performance may be affected by the transmission beam of the second communication station having an angle. Accordingly, the angular range of an arbitrary angle of arrival-based jump pattern group may include a non inter-group collision region (NICR) and an angle of arrival-based hop pattern group, which exclude transmission symbol collisions between the angle of arrival-based hop pattern groups. It is divided into an inter-group collision region (ICR) in which inter-transmission symbol collision may occur (see FIG. 8A). Of these, the range of inter-collision collision zones is equal to half of the transmit beam width at each boundary of any angle range of any angle-based hop pattern group, provided that the transmit beam width for each second station is fixed. This is the angle range plus the margin for measurement error. The forward link communication channels for the second communication stations with the angle of arrival in the inter-collision collision area have the effect of symbol collisions with the communication channels belonging to the adjacent angle of arrival-based hop pattern groups compared to those in the non-collision zone between intergroups. As a result, the overall symbol collision probability and the symbol puncturing probability increase.

9 illustrates the transmission symbols of forward link communication channels in any of the above-mentioned angle of arrival-based jump pattern group regions, except that they collide with transmission symbols of communication channels belonging to an adjacent angle of arrival-based hop pattern group. Accordingly, as a method for excluding the effect of the delay required for the change of the jump pattern on the collision probability due to the arrival angle of the corresponding second communication station leaving the area of the existing angle of arrival-based jump pattern group, the angle of arrival-based hop pattern subgroup ( An example conceptually illustrating an AGHPS-based random group-level hopping-pattern allocation (ARGHPA II) scheme for each AoA-based hopping-pattern subgroup (AHPSG).

Referring to FIG. 9 based on a difference from FIG. 8A, the angle of arrival-based jump pattern groups are set based on the angle of arrival information on the second communication station, and each angle of arrival-based jump pattern group is defined by two angles of arrival-based jump pattern. Separate into groups. Next, a random group level hopping pattern allocation method is applied to each arrival angle-based hopping pattern subgroup defined as described above, and each of the two subgroups in the random arrival-based hopping pattern group is based on an even / odd angle of arrival. hopping pattern portion group (Even / odd AoA-based hopping -pattern subgroup: AHPSG-E / O) of the definition and the number N _OC the coming into the halves of the orthogonal codes available for the forward link of the first communication station to each base N _OC / 2 orthogonal codes are allocated for each hopping pattern subgroup. Any angle of arrival based hop pattern subgroup generates individual hop patterns in the manner described with reference to FIG. 8B for the assigned N _OC / 2 orthogonal codes.

In the random-group-based jump pattern subgroup according to the angle of arrival-based jump pattern subgroup, any angle of arrival-based leap pattern subgroup may include other neighboring angle-based jump pattern subgroups (or neighbor-based angle of arrival-based jump pattern groups). Because they use a set of orthogonal codes different from each other, the forward link transmission symbols to the second communication station located at the angle of arrival-based hop pattern subgroup boundary do not collide with other forward link transmission symbols belonging to the neighboring subgroup and Arbitrary angle-based jump pattern reassignment of fast jump patterns because moving from a subgroup area to an adjacent area does not increase collisions on the corresponding forward link communication channel due to processing delays that occur during the reassignment of new jump patterns. The increase in system complexity and cost for the system can be greatly alleviated.

Due to the uneven distribution of the second communication stations in the service area of the first communication station in a real environment, any second communication station experiences in an orthogonal code hopping multiplexing scheme using a random orthogonal code hopping pattern for each forward link communication channel. The symbol collision and thus symbol puncturing probability is determined by the density of the second communication station in the region where the second communication station is located. This allows each second communication station to experience different symbol collision and symbol puncturing probabilities depending on the area in which it is located within the service area of the entire first communication station. In the situation where there is a difference in link quality due to a difference in symbol collision and symbol puncturing probability of each channel appearing in the forward link communication channel, the proposed angle of arrival based hop pattern group setting method can greatly alleviate this problem.

In this regard, an adaptive group width control that adjusts the angular width of the individual angle of arrival-based jump pattern groups periodically so that the number of second communication stations provided with the jump pattern by each angle of arrival-based jump pattern groups is uniform. We propose an adaptive group-width control (AGWC) method. This method uses the angle of arrival information for each second communication station. As described above, this information is basically information continuously measured from signals received from the first communication station for adaptive beamforming. No additional parameter measurement is required.

The basic operations of the adaptive group width control method are group-width contraction (GWC) and group-width expansion (GWE). As shown in FIG. 10, group width reduction is an operation of reducing the angle range of the angle of arrival-based jump pattern group when the number of second communication stations in any angle of arrival-based jump pattern group is larger than the reference value. The width extension is an operation of extending the angular range of the angle of arrival-based jump pattern group when the number of second communication stations in the angle of arrival-based jump pattern group is less than the reference value.

가 된다.An adaptive group width control method using the above two operations is shown in FIGS. 11A and 11B. 11A illustrates the overall process of the adaptive group width control scheme. Group width control in the adaptive group width control method is continuously performed at predetermined intervals, and the angle of arrival information of the second communication stations in the service area collected by the first communication station immediately before execution of the control is a parameter for adaptive group width control. Number of second stations in the angle control unit for each angle-based jump pattern group I ⁱ _k (i: indicator of the group for angle-based jump pattern, k (= 1, ..., N ⁱ _unit ): angle of arrival-based jump pattern In the order of the angle adjustment units specified in the counterclockwise direction in group i). The angle control unit is defined as a basic angle range control unit that adjusts the angle range of the angle of arrival-based jump pattern group when the adaptive group width is controlled, and includes N ⁱ _units within an arbitrary angle of arrival-based jump pattern group i. The sum of I ⁱ _k per angular adjustment unit is the number of second communication stations whose corresponding angle of arrival based hop pattern group i provides the hop pattern.

Becomes

로 설정하고 임의의 도래각 기반 도약 패턴 그룹 i 가 현재 지원하는 제2 통신국 수와 기준 파라미터의 차

를 개별 도래각 기반 도약 패턴 그룹별로 구한다. N_AHPG 개의 Dⁱ _U 들 중 가장 큰 값을 가지는 것을 D^max _U 로 설정하고 해당 도래각 기반 도약 패턴 그룹을 Gmax 로 지정한다. 상기의 과정을 통해 적응형 그룹 너비 제어에 필요한 파라미터들이 지정되면, 다음 단계(S112)에서는 도래각 기반 도약 패턴 그룹 Gmax 에 대해 그룹 너비 축소를 수행하고 단계(S113)에서는 도 11A에 도시된 바와 같이 도래각 기반 도약 패턴 그룹 Gmax 를 중심으로 하여 좌우 양쪽에 있는 도래각 기반 도약 패턴 그룹들에 대해 번갈아 가며 그룹 너비 제어 순서 s(s=0 은 Gmax 를 지칭함)를 지시자로서 재지정하고 Dⁱ _U 값을 기반으로 그룹 너비 축소 또는 그룹 너비 확장을 순서대로 수행한다.In the first step (S111) of adaptive group width control, parameters used in the control method are specified. First, the average of the number of second communication stations supported for each angle-based jump pattern group is referred to as a reference parameter for group width control.

Difference between the reference parameter and the number of second communication stations currently supported by any angle of arrival based hop pattern group i

Is obtained by individual arrival angle-based leap pattern groups. The largest value among N _AHPG D ⁱ _U is set to D ^max _U and a corresponding angle of arrival based jump pattern group is designated as G ^max . If the parameters necessary for the adaptive group width control are specified through the above process, in step S112, the group width reduction is performed for the arrival angle-based jump pattern group Gmax, and in step S113, as shown in FIG. 11A. arrival the incoming alternating for each of the base hopping pattern group group width control sequence s D ⁱ _U value reassign (s = 0 is referred to Gmax) a as an indication that the right and left sides to the center at each based hopping pattern group Gmax Group width reduction or group width expansion is performed in order.

FIG. 11B is a flowchart showing the group width control method of steps S112 and S113 as a whole. When step S112 of FIG. 11A starts 1101, the angle of arrival based jump pattern group Gmax is designated (1111) and the operation number value m is initialized (1112), until D ^s _U of Gmax is smaller than zero. The group width reduction process proceeds to the angle adjustment unit level (1113). In the process of reducing the width of each group, m is increased by 1 (1114) and D ^s _U is subtracted from the number of users in the angle control unit as the angle width is reduced by alternating both boundary portions of the corresponding angle of arrival-based jump pattern group. One value is updated as shown in Equation (1) (1115).

...(1)

...(One)

The N ^s _unit value is then updated by decreasing the width of the group by 1 (1116). After performing the group width reduction for Gmax corresponding to step S112 described above, readjust the peripheral angle-based jump pattern groups s = 1, s = 2 to accommodate the angle adjusting unit subtracted from Gmax. After (1121), the group of arrival-based jump patterns in the next order is designated (1122) and m is initialized (1123). When the size of D ^s _U of the specified arrival angle-based leap pattern group s is smaller than 0 (1124), the group width expansion is performed when the size is smaller than 0, and the group width reduction is performed when the size is larger than 0. In the group width expansion operation, the group width expansion process proceeds to the angle adjustment unit level until D ^s _U of the corresponding angle of arrival-based jump group becomes greater than 0 (1131). In each group width expansion process, m is increased by 1 (1132), and the group width expansion is performed at the boundary of the boundary except for the boundary where the group width control of the corresponding angle of arrival-based jump pattern group is already performed, and D ^s of the group _U is updated as Equation (2) with the number of users in the angle adjusting unit added (1133).

...(2)

...(2)

The N ^s _unit value is then incremented by 1 by the group width extension (1134). If D ^s _U of the specified arrival angle-based jump pattern group s is greater than 0 (1124), the group width reduction is performed, and the group width reduction process is angled until D ^s _U of the arrival angle-based leap group is less than zero. Proceed to the adjustment unit level (1141). In the process of reducing the width of each group, m is increased by 1 (1142), and the group width is reduced at the remaining boundary except for the boundary on which the group width control of the corresponding angle of arrival-based jump pattern group has already been performed, and D ^s _U is updated as shown in Equation 3 below by subtracting the number of users in the added angle adjusting unit (1143).

...(3)

... (3)

Thereafter, the N ^s _unit value is updated by decreasing it by 1 by expanding the group width (1144). Change the group width of adjacent angle of arrival-based jump pattern groups (without adaptive group width control yet applied) to accommodate the resulting change after the end of group width control for that angle of arrival-based jump pattern group. Update the N ^s _unit value and the D ^s _U value (1121) and specify a group of angles of arrival-based jump patterns to perform the next group width control (1122). Given that the group width of the angle of arrival-based jump pattern group, which originally corresponds to the last sequence, is determined by the group width control process for the previous groups, total N _AHPG -1 group width control including step S112 as a whole After performing the process (1151), the adaptive group width control process at that time is terminated (1152).

The adaptive group width control method can be applied to both a random group level hopping pattern allocation method for each arrival angle-based hopping pattern group and a random group level hopping pattern allocation method for each arrival angle-based hopping pattern subgroup. Applying the adaptive group width control method to the angle of arrival-based jump pattern group and setting the angular range of the lower two angles of arrival-based jump pattern subgroups to half of the group of the higher jump pattern, and adapting each angle of arrival-based jump pattern subgroup Two detailed application methods may be used, in which the type group width control method is applied and as a result, the angle range of the upper angle of arrival based hop pattern group is determined. The period for performing the adaptive group width control process is determined according to the system requirements for the mobility of the second communication station and the link quality of the forward link communication channel, and adaptively changes the period according to the change of the system situation. It is also possible to apply.

In the code division multiplexing scheme, the orthogonal code may be reused for the user beams in the unit service area of the first communication station in order to provide the number of user channels corresponding to the greatly increased forward link capacity by applying the adaptive beamforming array antenna. In the case where transmission beams using the same orthogonal code exclusively allocated are overlapped, continuous frame errors may occur due to severe reception interference of the corresponding forward link communication channel, and thus a communication channel may be disconnected. In order to prevent this, a high accuracy location tracking technique and a perfect channel retrieval / reallocation scheme are required for all second communication station transmission beams in the service area, and a considerable amount of additional system complexity and load is required to support this. .

Unexpected near-far effect when using multi-scrambling code or quasi-orthogonal code as a user channel code as an alternative to solve the complexity and load problems caused by reuse of orthogonal codes. This can cause a significant amount of receive interference. On the other hand, in the orthogonal code hopping multiplexing scheme using the intelligent beam array antenna, when an overlap occurs between arbitrary second transmission station transmission beams, symbol interference due to orthogonal code hopping in symbols instead of continuous interference does not occur in the corresponding second communication station. Because we experience the probability of, we can expect recovery by channel coding / decoding techniques for random symbol unit errors. As a result, the large number of user channels and adaptive beamforming arrangements provided by orthogonal code hopping multiplexing avoids the increased system load and complexity due to the use of special orthogonal code reassignment techniques or multiscrambling codes, and further increases the interference. The increase in link capacity provided by the antenna can be effectively combined.

The configuration of the present invention has been described above by specific embodiments such as specific components and limited embodiments and drawings, but it is provided to help general understanding of the present invention. The present invention is not limited to the above embodiments, and those skilled in the art may add various forms of modifications and variations from this description.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and all subjects having equivalent or equivalent modifications to the claims as well as the following claims are intended to be included in the scope of the present invention. will be

According to the present invention, spatial filtering is performed to alleviate the degradation of link quality due to symbol puncture due to inter-symbol collision caused by random orthogonal code hopping patterns in the forward channel transmission in the conventional orthogonal code hopping multiplexing scheme. By applying an adaptive beamforming array antenna that provides a function to an orthogonal code hopping multiplexing scheme, the frequency of symbol punctures for any user load is significantly reduced compared to the case of using a basic omni-directional antenna or sector division antenna. Have

In addition, according to the proposed group level random hopping pattern allocation scheme, when the number of forward link communication channels provided to the second communication stations is less than or equal to the number of available orthogonal codes, symbol collisions are completely excluded and consequently orthogonal code division multiplexing. Provide link quality equivalent to the scheme.

In addition, even when the number of forward channels provided by the first communication station exceeds the number of available orthogonal codes, the frequency of symbol collisions and punctures is significantly lowered than in the case of using a random hopping pattern in the conventional orthogonal code hopping multiplexing scheme. Can be.

On the other hand, according to the proposed angle-based jump pattern subgroup random group level leap pattern allocation method, it is required to exclude the collision area between groups and to switch to the leap pattern group existing at both boundaries of the arbitrary angle-based jump pattern group. The effect of delay in processing can be eliminated. In addition, the proposed adaptive group width control method maintains uniform symbol collision and puncturing probability in each forward link communication channel with respect to non-uniform distribution of second communication stations in the service area of the first communication station appearing in the real environment. Can be.

In addition, the present invention is defined as a symbol collision in which the influence of interference on the reception of the corresponding forward link communication channel according to the position of the second communication station due to the leap of the orthogonal code in symbol units is limited within the symbol interval and consequently deteriorates the link quality. By applying the schemes proposed in the present invention to the generation of symbol puncturing that causes a significant reduction in the frequency and significantly overcomes the channel coding / decoding gain, system complexity and processing load can be greatly reduced.

Claims (24)

A transmitter apparatus of a first communication station for providing a service area to at least one second communication station and transmitting data through a forward link communication channel to a second communication station located in the service area. A hop pattern generator for generating an orthogonal code hopping pattern corresponding to a forward link communication channel to each second communication station; An orthogonal code generation unit generating an orthogonal code to be allocated to each symbol section of the orthogonal code hopping pattern; A band spreader which spreads a transmission symbol to each second communication station by using the generated orthogonal code to generate a transmission signal; And A weight vector corresponding to a forward link communication channel to each second communication station is generated based on the angle of arrival information of each second communication station that is periodically measured, and the weight vector is applied to the spread spectrum transmission signal. Adaptive beamforming array antenna unit for transmitting to each second communication station through a beamforming antenna Transmitter device comprising a. The method of claim 1, Comparing each symbol section of a separate orthogonal code hopping pattern respectively corresponding to a separate second communication station, detecting when the orthogonal codes of the separate orthogonal code hopping pattern match in a specific symbol period (hereinafter, "symbol collision") A symbol collision detection unit; And A symbol collision control unit for adjusting a transmission symbol value to the second separate communication station according to whether or not the transmission symbol value to the second second communication station is the same when the symbol collision is detected; Transmitter device further comprising. The method of claim 2, And the symbol collision control unit adjusts the value of each transmission symbol to '0' when the transmission symbols to the second separate communication station are different. The method of claim 2, The symbol collision detection unit transmits a forward link communication channel to other second communication stations having a angle of arrival within the symbol collision detection angle range by using a predetermined range around the angle of arrival of each second communication station as a symbol collision detection angle range. Transmitter device, characterized in that for comparing the collision with the symbol. The method of claim 1, Arrival angle information extraction unit for extracting the angle of arrival information of each of the second communication station from the signal received through the reverse link communication channel from each of the second communication station Transmitter device further comprising. The method of claim 5, And the angle of arrival information extracting unit measures the angle of arrival information of each second communication station according to a period shorter than a frame period. The method of claim 1, And the adaptive beamforming array antenna unit sets the angle of arrival of each second communication station to the maximum transmission beam direction of a forward link communication channel to each second communication station. The method of claim 1, And the hopping pattern generator divides the service area of the first communication station into a plurality of partitions, and independently generates a hopping pattern for forward link communication channels belonging to each of the divided areas. The method of claim 8, The hopping pattern generator generates at least one collision avoidance group by grouping the entire hopping pattern into a plurality of hopping pattern units in which symbol collisions do not occur, and the same collision is performed for the forward link communication channels belonging to the respective partitions. Transmitter device, characterized in that the first allocation of the jump patterns included in the exclusion group. The method of claim 9, The hopping pattern generation unit is configured to forward the forward link communication channel to the second communication station corresponding to the excess when the number of second communication stations belonging to each of the divided areas exceeds the total number of hopping patterns included in the collision avoidance group. Assigning a hopping pattern included in another collision avoidance group for each other. The method of claim 8, The hop pattern generation unit may include at least one of a size of each collision avoidance group, a total number of jump patterns included in the collision avoidance group, and an individual hop pattern in the arrival angle information of each second communication station measured in a period of a frame period or more. And adaptively change accordingly. The method of claim 1, The leap pattern generation unit generates at least one collision avoidance group by grouping the entire leap patterns into a plurality of leap pattern units in which symbol collisions do not occur, and divides the entire user area into a plurality of angular ranges. And preferentially assigning a hopping pattern included in the same collision avoidance group to a forward link communication channel to a second communication station having an angle of arrival within an angular range. The method according to claim 8 or 12, wherein And the orthogonal code generation unit shares an orthogonal code set for modulating transmission symbols of a forward link communication channel belonging to the different partitions between different partitions. The method according to claim 8 or 12, wherein An angular range control unit for adaptively changing the angular range of the divided area according to the number of second communication stations in the divided area Transmitter device further comprising. The method of claim 14, The angular range controller extends the angular range when the number of second communication stations in the divided area is less than a preset reference value, and reduces the angular range when the number of second communication stations in the divided area is larger than a preset reference value. Transmitter device, characterized in that. The method of claim 8, The leap pattern generator divides each divided area into a plurality of subdivided areas according to an angular range, divides the entire orthogonal code set assigned to the divided areas according to the number of the subdivided areas, and belongs to the subdivided areas. And spreading modulating a transmission symbol of a forward link communication channel using the divided orthogonal code set corresponding to the subdivision region. A transmitter apparatus of a first communication station for providing a service area to at least one second communication station and transmitting data through a forward link communication channel to a second communication station located in the service area. Through a forward link communication channel to the second communication station, the transmission symbols are spread by using an orthogonal code selected for each transmission symbol unit according to a predetermined hop pattern, and then through an adaptive beamforming array antenna to the second communication station. Transmitter device, characterized in that for transmitting. Generating an orthogonal code hopping pattern corresponding to each of the second communication stations located in the service area provided by the first communication station and an orthogonal code for each symbol section of the orthogonal code hopping pattern; A second step of spreading a symbol to be transmitted to the second communication station by using the generated orthogonal code to generate a symbol signal to be transmitted; And Transmitting the symbol signal to the second communication station via an adaptive beamforming array antenna; Data communication method comprising a. The method of claim 18, The second step, Extracting angle of arrival information from a reverse link received signal from the second communication station; And Setting in the maximum transmission beam direction of the second communication station based on the angle of arrival information Data communication method further comprises. The method of claim 18, A fourth step of dividing the service area provided by the first communication station into a plurality of divided areas according to an angle range; More, And wherein said first step generates and assigns said orthogonal code hopping pattern to a forward link communication channel belonging to said partition in each partition. The method of claim 20, The fourth step divides the divided area into a plurality of detailed divided areas according to an angle range, The first step is to divide the entire orthogonal code set assigned to the partitioned area into the number of the detailed partitioned areas, and to use the modulation for transmission symbols of the forward link communication channels belonging to the respective detailed partitioned areas. Data communication method characterized in that. The method of claim 20, A fifth step of adaptively changing the angular range of the divided region according to the number of second communication stations belonging to the divided region; Data communication method further comprises. The method of claim 22, The fifth step may include expanding the angular range when the number of second communication stations belonging to the divided area is less than a preset reference value; And Reducing the angular range when the number of second communication stations belonging to the divided area is larger than a preset reference value Data communication method comprising a. A computer-readable recording medium having stored therein program code for performing a data communication method according to any one of claims 18 to 23.

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