JP3626055B2 - Radio terminal apparatus, base station, and reverse common channel random connection method in code division multiple access system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless terminal device, a base station, and a plurality of terminal devices that transmit data via a common channel using a code division multiple access method.randomThe present invention relates to a connection (Random Access) method.
[0002]
In more detail, the present invention relates to one of the preamble signatures that can be used by the terminal device.,and,One of the available access slots,Is transmitted to the base station, the base station acquires the preamble, and this preambleButcaptureWhether or notTo the terminal device, the terminal device transmits data according to the result of capturing the preamble or retransmits the preamble, thereby reducing unnecessary data transmission, reducing interference signals, and improving network efficiency. Only the preambleofBy performing fast retransmission, it becomes possible to quickly reach an appropriate power level, and the reverse direction is achieved by a code division multiple access system with excellent time delay characteristics.(Up direction)Common channelrandomThe present invention relates to a connection apparatus and method.
[0003]
[Prior art]
The mobile communication service, whose demand is rapidly increasing, has not been activated yet. However, the mobile communication service that supports the data service has not been activated as a service form that enables voice information transmission while moving. In simple data transmission, there is an increasing demand for moving image signal reception during movement. In particular, not only audio signals but also simple data to video are supported, and services can be received anywhere in the world through internationally integrated standards.3rd generationResearch on IMT-2000 (International Mobile Telecommunication-2000) for mobile communication services has been actively conducted in Japan and overseas. In addition, although mobility is somewhat limited, research for high-speed data transmission has also been conducted, and in particular, the wireless LAN presented in the IEEE 802.11 standard proposal has already been 2 Mbps (Mega bit per sec) data. Has been commercialized as a product that can transmit.
[0004]
Generally, such high speed data transmissionWhen doingCircuit-switch currently used in public switched networks, digital cellular and personal mobile communication systemsThenInefficient use of limited channelsBecauseIs not desirable. As a measure for solving the problems of such a circuit switching system, IMT-2000, which is being studied as a standard plan for a short-distance regional network and a next-generation mobile communication system, uses a packet switching system for high-speed data transmission. (Packet-switch) is applied.
[0005]
On the other hand, the CDMA (Code Division Multiple Access) signal system bandwidth spreading method applied in the digital cellular system currently in service increases the capacity and cannot be wiretapped from the outside. There is a feature that communication can be stably performed in a multipath environment generated by a rapidly changing wireless channel.
[0006]
The IMT-2000 system, which is currently undergoing standardization activities, has the basic requirement of supporting packet data as well as existing voice data. However, due to the non-periodic characteristics of packet data, As described above, the method of using the dedicated channel has a problem that resources cannot be used efficiently. That is, continuous data such as voice data is allocated and used as a dedicated channel, whereas in the case of packet data that is discontinuous and variable in the amount of data to be transmitted, If a dedicated channel is used, there arises a problem that the capacity supported by the system cannot be satisfied.
[0007]
Therefore, the appropriate number of reverse directions(Up direction)If channels are shared, resources can be used efficiently.Not onlyThe voice service and the service with variable amount of data to be transmitted can be accommodated within the capacity range of the system. In addition, it is expected that the amount of data transmitted by subscribers will increase in the future.(Up direction)Efficient use of resources using common channels should be an essential issue.
[0008]
Reverse direction like this(Up direction)The ALOHA method is known as the simplest method for channel connection using a common channel and data transmission. ALOHA method is typicalrandomAs a connection method, it was developed as a protocol for a wireless network between Hawaiian islands at the University of Hawaii in 1970. In the ALOHA method, data is transmitted without a separate time plan between the base station and the terminal device.FromData transmission efficiency is reduced,In particularWhen there are many terminal devices, between transmission dataofCollisions occur frequentlyBecauseNetwork overload phenomenon occursdid. thereTo determine this problem, base station and terminal equipmentWithA slot ALOHA with a standard time in between was studied. Slot ALOHAsoCauses data to be transmitted by the terminal deviceIf, Reference timeInsideonlyofData transmission efficiency by allowing transmissionTheincreaseI am letting. The reason isThis is because the probability of being disturbed by its own data transmission due to data generated in other terminal devices is reduced, and the efficiency of the network is generally improved.
[0009]
Next, a conventional ALOHA protocol using a code division multiple access method will be described with reference to FIG.
[0010]
FIG. 9 illustrates a data transmission process in the ALOHA protocol using a conventional code division multiple access system.
[0011]
According to FIG. 9, the terminal device transmits data through one access attempt. This connection attempt is composed of a plurality of access sub-attempts, and the access sub-attempts are The connection probe sequence is composed of a plurality of connection probes. The connection probe sequence is composed of a plurality of connection probes.
[0012]
This connection probe includes a connection channel message or a preamble transmitted in the form of a simple pilot before transmission of user data, and connection information and user data following this preamble, in order to capture terminal device timing. This is done with an access message capsule.
[0013]
Through the connection attempt process configured as described above, a terminal device that intends to transmit a connection message or data on a reverse common channel first transmits one connection probe at a constant power level. The power level used at this time not only reduces the influence of interference on other terminal devices that transmit data using dedicated channels or transmit data through other reverse common channels, but also reduces the number of retransmissions. Use the best one to reduce the processing time through.
[0014]
Attempt data transmission with first connection probeShiThe terminal device monitors an indication as to whether or not a connection probe has been detected from the base station for a certain time (TA). However, if data transmission of the first connection probe fails, any time (RSIn this case, retransmission is performed at a power level increased by a certain level (PI) from the power level of the first connection probe.
[0015]
Through such a process, the terminal device continuously attempts a connection probe including data transmission. However, if data transmission can no longer succeed within a preset number of connection probes, after terminating one connection probe sequence and waiting for another arbitrary time (RS), the terminal device performs the second connection probe sequence. It will begin in the same way as when the first connection probe is transmitted.
[0016]
[Problems to be solved by the invention]
However, the ALOHA method is also fundamentallyConflictIn order to transmit data with an appropriate power level in the contention mode, an insufficient power level between transmission data and failure of connection probe due to collision cannot be avoided, resulting in useless transmission failure.
[0017]
On the other hand, there is also a method of using a large number of preamble signatures in order to improve the probability of capturing a preamble. Preamble signature is,Reverse direction(Up direction)Modulates a common spreading code used in the preamble for the common channel,A sequence composed of a plurality of symbols. Since orthogonality is maintained between preambles, the base stationIsDifferent preamble signaturesByA large number of preambles can be captured simultaneously.
[0018]
As long as the preamble is a signal for capturing the synchronization of the reverse common channel, more stable synchronization can be obtained if the preamble becomes longer, but this is not effective in terms of transmission efficiency.
[0019]
Therefore, the object of the present invention is to solve the above problems.To doOne of the preamble signatures available to the terminal device,and,One of the available access slots,Is transmitted to the base station, and the base station acquires the preamble, and this preambleButcaptureWhether or notIs transmitted to all terminal devices, and the terminal device transmits data according to the preamble acquisition result.OrBy retransmitting the preambleRReduce unnecessary data transmissionTheReduce interference signalAnd thenImprove network efficiency,AndOnly the preambleofFast access to appropriate power levels by performing fast retransmissionsAnd thisReverse direction in code division multiple access system with excellent time delay characteristics(Up direction)Common channelrandomIt is to provide a connecting apparatus and method.
[0020]
[Means for Solving the Problems]
Therefore, the reverse common channel in the code division multiple access system according to the present inventionrandomAccording to the connection apparatus and method, when a terminal apparatus transmits a preamble modulated with a preamble signature, in order to effectively operate various packet data, a 1 from a subset of preamble signatures divided according to traffic characteristics. Two preamble signaturesrandomSelect
[0021]
In addition, the base station captures the preambles for all available preamble signatures, and then reports the captured preamble signatures to all terminal devices using a forward link common channel. Whether the transmitting terminal device captures the preamble sent by itself(Ie whether it was captured)To be able to confirm. If the preamble catchesIf you wereThe terminal device transmits information data to the user at a predetermined time at a power level appropriately set according to the power level at the time of transmitting the preamble. However, the preamble capturesIsIf not, the terminal device obtains the access time (access time) and the preamble signature.randomThe power level increased by comparison with the power level of the previous preamble is determined by a power step defined in advance, and the preamble is retransmitted.
[0022]
In order to achieve the above object, the reverse direction in the code division multiple access system according to the present invention(Up direction)Common channelrandomConnection apparatus and methodInThe base station acquires the preambles transmitted from the plurality of terminal devices through the reverse common channel for all available preamble signatures, and acquires the preamble signatures transmitted from the plurality of terminal devices. How(Ie whether it was captured)Forward signal representing(Downward)A plurality of terminal devices transmit preamble signatures classified according to characteristics of data to be transmitted.randomSelect a signal to modulate a preamble, receive a signal representing a preamble acquisition indication transmitted from the base station via a common channel, and capture the transmitted preamble signature.IsThe user information data is transmitted at a predetermined time at a power level appropriately set according to the power level at the time of preamble transmission, and the transmitted preamble signature is captured.IsIf not,ConnectionIn the slotrandomThe preamble is retransmitted with the selected preamble signature.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the reverse direction in the code division multiple access system according to the present invention(Up direction)Common channelrandomThe connection device will be described with reference to the drawings.
[0024]
FIG. 1 is a network configuration diagram of a general code division multiple access system for applying the present invention. Network generates data in the reverse direction(Up direction)The terminal apparatus 100 that transmits the preamble data through the common channel, and the preamble that is transmitted from the terminal apparatus 100 through the reverse common channel are used to perform code acquisition, and the preambleTheThe terminal device 100 is notified as to whether or not it has been captured, and the terminal deviceFromBase station 200 that receives corresponding user information data and works with a higher layer protocol, CDMA network 300 that manages a plurality of base stations 200 and 210 and works with other networks, and works with CDMA network 300do itThe terminal device 100 and a general telephone subscriber are combined.PInterlocks with STN (Public Switched Telephony Network) 400 and CDMA network 300do itCombine terminal device 100 and Internet userDoLinked with Internet 500 and CDMA network 300do itCombine terminal device 100 and data server receiving data service supportDoIt is composed of a PSDN (Public Switched Data Network) 600.
[0025]
Network configured in this wayInReverse direction(Up direction)Common channelrandomConnecting device is a base stationInsideIncluding an acquisition indication signal transmission means, and a terminal deviceInsideFurther includes a capture display signal receiving means and a transmission determining means.
[0026]
The transmission means of the base station 200 is that the preamble code acquisition is in the reverse direction.(Up direction)Transmitted preamble signature after being performed on all available preamble signatures over a common channelTheA capture display signal that displays on all the terminal devices whether or not it has been captured is transmitted. The receiving means of the terminal device is forward(Downward)Base station via common channelfromReceive capture indication signal,Terminal deviceThe determining means is user information data according to the captured display signal.ThetransmissionYouOr preambleTheTransmission againYouDecide what to do.
[0027]
If the preamble signature capturesIsIs displayed, the terminal device transmits user information data, otherwiserandomSelected preamble signature and newly selectedConnectionTransmit the preamble again with increased power in the slot.
[0028]
Figure 2,Code division multiple access system according to the present inventionbyReverse direction(Up direction)It is a functional block diagram of the terminal device and base station in the random connection apparatus of a common channel.
[0029]
The terminal device 100 randomly selects one of the available preamble signatures classified according to traffic characteristics and a connection slot to transmit, and forward path loss, interference signal reported from the base station A terminal first determination unit 110 that determines a preamble power using a level and the like, and a terminal first that generates and transmits a preamble signal with a preamble signature and a power level in a connection slot selected by the terminal first determination unit 110 The transmission unit 120, a terminal first processor 170 that formats user information data activated and transmitted by the terminal first determination unit 110, and a user information signal formatted from the terminal first processor 170 are input. Chan corresponding to the preamble signature And Le codes (channelization code) terminal second transmission unit 180 to output the spread spectrum in the preamble generated by the terminal first transmission portion 120 in accordance with acquisition indication signal transmitted from the base station 200signalOr a terminal selection unit 130 that selects one of the data generated by the terminal second transmission unit 180, and a signal selected by the terminal selection unit 130 is converted into an RF signal and transmitted to the base station via a radio channel. 200, and a terminal second processor 140 that converts an RF signal capture display signal transmitted from the base station 200 into a baseband signal, and a baseband capture display signal input from the terminal second processor 140 and transmitted. The terminal receiving unit 150 for confirming whether the preamble signature is captured, and the terminal first determining unit 110 is enabled / disabled according to the capture result of the transmission preamble signature confirmed by the terminal receiving unit 150, and the switch of the terminal selecting unit 130 And a terminal second determination unit 160 that outputs a signal for switching between.
[0030]
As illustrated in FIG. 3, the terminal first determination unit 110 is forwarded from the base station.(Downward)Signature storage unit 111 that receives and stores information on preamble signatures classified according to traffic characteristics transmitted through a common channel, and characteristics of data generated in consideration of traffic characteristics and requirements in higher layers And a signature selection unit 112 that selects a preamble signature from among available preamble signatures corresponding to traffic characteristics in a random manner, and when the preamble is transmitted, randomly or deterministically. ,ConnectionSlot selector 113 for selecting slots, interference signal level of base station, and forward direction(Downward)A power determination unit 114 that determines the power of the preamble to be transmitted in consideration of the path loss and the previously transmitted preamble power level and the like.
[0031]
Power decision unit 114 is forward from base station(Downward)Base station interference signal level transmitted over common channel and forward direction(Downward)The power level is determined in consideration of the path loss, the predetermined power increase step, the power level of the previous preamble, and the like.
[0032]
Again in FIG.The terminal first transmission unit 120 is determined by the terminal first determination unit 110.ConnectionUsing the slot, preamble signature and power level, the preamble is transmitted by modulating the common spreading code with the preamble signature, and the selected preamble signature and the common band spreading code are used. Generate a complex band spread signal whose real value is identical to the imaginary value.
[0033]
The terminal receiving unit 150 receives the capture display signal using a signature that is the same as the transmitted preamble signature and the code used for capture display transmission on the forward link.
[0034]
In addition, the terminal second determining unit 160 captures the preamble signature transmitted by the capture display signal received by the terminal receiving unit 150.IsIf so, the terminal first determination unit 110disableTerminal selection unit 130 and terminalSecondTransmission unit180On the other hand, if not, the terminal first determination unit 110 isEnableLet the terminalFirstTransmission unit120Are coupled to the terminal selection unit 130.
[0035]
The base station 200 receives the RF signal transmitted from the terminal apparatus 100, and base station the base station processor 210 that transmits the RF signal to the terminal apparatus 100 and the preamble transmitted from the terminal apparatus 100 via the reverse common channel. A base station synchronization unit 220 that performs acquisition of this preamble with all available preamble signatures input from the station processor 210; a base station determination unit 230 that determines and outputs a preamble signature that is captured by confirming the acquisition; A base station transmission unit 240 that generates a plurality of acquisition display signals corresponding to the acquisition preamble signature input from the base station determination unit 230 and outputs the acquired acquisition display signals to the terminal device 100 via the base station processor 210; Base station determination unit receiving multipath time delay information acquired by station synchronization unit 220 30 is used to generate a despreading code using information on the captured preamble signature received from 30 and receive data transmitted from the terminal device 100 via the reverse common channel from the base station processor 210 and perform demodulation and channel decoding. It comprises a base station transceiver 250 that performs transmission and the like.
[0036]
The base station synchronization unit 220 receives a preamble transmitted from the terminal device 100 through the reverse common channel by the base station processor 210 and acquires a preamble with all available preamble signatures, and a captured preamble. A time delay characteristic output unit that causes the base station transceiver 250 to recognize all the time delay characteristics corresponding to the signature and prepares the transceiver 250 to receive data to be transmitted at an arbitrary predetermined time; and a base station determination unit And an output unit that outputs a capture display signal that reports the preamble signature captured at 230.
[0037]
The base station determination unit 230 notifies the base station transceiver 250 of a band spreading code corresponding to the preamble signature received from the base station synchronization unit 220 and prepares to receive data transmitted immediately at a predetermined time. The generation unit and an acquisition display signal generation unit that generates an acquisition display signal corresponding only to the captured preamble signature and outputs this signal to the base station transmission unit 240.
[0038]
The base station transmission unit 240 divides the available time by the number of available signatures, assigns the time obtained by the division to each available preamble signature, and is assigned to the captured preamble signature. On-off signal format (# 1) that transmits the captured display signal only at the time and does not transmit the captured display signal at the time assigned to the preamble signature that was not captured, and the number of signatures that can use the available time Divide by and assign each divided time to each available preamble signature, and a positive capture indication signal for the preamble signature captured for all divided times assigned to the available preamble signature. Preamble signal that was transmitted and not captured Corresponding to the captured preamble signature by setting an orthogonal signal format (# 2) for transmitting a negative capture display signal to the channel and assigning an orthogonal code to the preamble signature and transmitting it. On-off signal format (# 3) for transmitting only orthogonal symbols to be transmitted, and a symbol to be transmitted by assigning an orthogonal code to the preamble signature, and transmitting a positive acquisition indication signal for the captured preamble signature, A preamble signature that has not been captured is configured to transmit a captured display signal based on one of the signal formats of antipodal signal format (# 4) that transmits a negative captured display signal. . It is also possible to combine four signal formats to create another signal format for use.
[0039]
The acquisition display signal transmission system includes a puncturing method that is applied to a forward common channel that is used, a method that uses a code having orthogonality in the forward common channel, and an orthogonality to the forward common channel. Any one of the methods using a code having no symbol is selected and transmitted.
[0040]
In addition, the base station 200 assigns a dedicated channel for transmitting packet access for transmitting short data, a channel reservation request for transmitting intermediate data, and large continuous data such as voice data. The channel request for requesting the data classifies the nature of data transmitted through the reverse common channel. Then, the base station 200 classifies all possible preamble signatures according to the nature of the data to be transmitted, and broadcasts them through the forward common channel so that all terminal apparatuses can recognize them.
[0041]
To base station 200Packet accessIn order to do so, the terminal apparatus 100 transmits a preamble with one preamble signature among the preamble signatures divided according to data characteristics such as the length of data to be transmitted through packet access and the transmission rate, and the base station 200 Is used to determine whether to retransmit the preamble or to transmit user information data. If user information data is transmitted, single or multiple frames that conform to the frame structure are continuously transmitted, and packet access operation is performed for frames that have failed to be transmitted among the transmitted frames. Do it again.
[0042]
For the channel reservation request, the terminal device 100 selects one of the preamble signatures assigned for the channel reservation request.randomAnd the base station 200 captures the preamble transmitted from the terminal apparatus 100 and notifies the captured preamble to all terminals through the forward common channel. If the terminal device 100 displays a negative capture display or no capture display, the terminal device selects one of the preamble signatures assigned for channel reservation.randomSelectConnectionThe slot is determined and the preamble is retransmitted, and the terminal device 100 captures the preamble signature.IsWhen the preamble is transmitted, the user information data for the reservation request is transmitted and the channel reservation data is transmitted to thereby reserve the channel. In the base station 200, after correctly receiving the transmitted data for the channel reservation from the terminal device, the forward direction(Downward)How to make channel reservations using a common channel(Ie, reservation availability)The reserved time, spreading code, and transmission rate are notified to the corresponding terminal device, and the corresponding terminal device uses the reserved time, spreading code, and transmission rate to transmit the data to be transmitted. Transmit and forward(Downward)Closed loop power control is performed using a power control command transmitted through the channel. Then, when transmitting the final frame, the terminal device transmits information indicating that the data transmission is completed together with the data to cancel the channel reservation.
[0043]
One method for changing channel reservation conditions during reservation is a method in which the terminal device 100 transmits data for changing channel reservation conditions together with data transmission in the same manner as an operation for packet access or channel reservation request. There is. The other method is a method in which the terminal device 100 multiplexes data for changing channel reservation conditions together with user information data and transmits the multiplexed data. In both methods, the base station 200 must transmit information related to acceptance or rejection.
[0044]
Hereinafter, the code division multiple access system according to the present inventionInReverse direction(Up direction)Common channelrandomThe operation of the connection device will be described.
[0045]
FIG. 4 shows a terminal device and a base station in a random access device according to the present invention.StationIt is the schematic explaining the operation | movement between.
[0046]
FIG. 4 will be described. When data to be transmitted is temporarily generated, the terminal device 100 transmits a preamble to the base station 200, and the base station 200 acquires a preamble code and transmits an acquisition display signal for preamble code acquisition to all the terminal devices 100. As a result, each terminal apparatus 100 monitors the captured display signal, and the preamble transmitted by itself is captured.IsIf not, retransmit the preamble and capture the transmitted preamble.IsIf so, user information data is transmitted. The base station 200 that has received the data receives the user information data, and transmits an acknowledgment signal of the user information data to the terminal device 100 after the error check. Preamble capturesIsThe time that did not exist is called idle time (IT).
[0047]
As shown in FIG. 5, when the data to be transmitted is generated (S101), the terminal device 100 operates as one of the available preamble signatures corresponding to the traffic characteristics in order to transmit the preamble. OneConnectionSlotrandom(S102), and the step of determining the power of the preamble to be transmitted using information on the forward path loss, the interference signal level transmitted from the base station 200, etc. is performed (S103). Next,randomSelectedConnectionIn the slot,randomA preamble is generated and transmitted with the selected preamble signature and the determined power level (S104).
[0048]
Then, the terminal device 100 receives the preamble capture display signal broadcast from the base station 200 to all the terminal devices 100 (S105), and the preamble signature transmitted by itself is captured.IsIt is confirmed whether or not (S106).
[0049]
If the preamble transmitted by itself is captured in the process of receiving the captured display signal, the terminal device 100 formats the user information data in a predetermined format and selects the message or preamble.ShiBand spreading of specific spreading code corresponding to preamble signaturedo itData transmission to be transmittedStepIf the preamble transmitted by itself is not captured in the process of receiving the captured display signal, the terminal device repeats the steps starting from the step of determining transmission resources such as preamble signature, connection slot, and power level. Is retransmitted (S108).
[0050]
On the other hand, the base station 200 controls transmission of a preamble capture display signal as illustrated in FIG. First, the base station 200 receives an RF signal at a terminal device (S201), and acquires a preamble code in order to acquire synchronization for the preamble with all available preamble signatures (S202). Next, the base station confirms whether the preamble has been captured, determines the captured preamble signature (S203), generates a captured display signal corresponding to the captured preamble signature, and transmits this to all terminal devices (S204). ).
[0051]
The base station 200 acquires the multipath time delay information and fading phase information acquired in the preamble code acquisition step, generates a despread code using the acquired preamble signature information, and prepares for reception ( In step S205, the terminal device receives data transmitted through the reverse common channel, and receives user information data through demodulation and channel decoding processes (step S206).
[0052]
The above operation will be described in more detail. When the terminal first determination unit 110 is enabled from the outside, one preamble signature is randomly selected from a set of preamble signatures classified according to the characteristics of the data transmitted by the enabled terminal first determination unit 110 and connected simultaneously. A slot is also selected at random. Next, the terminal first transmission unit 120 generates a preamble that is transmitted by spreading the preamble signature using the common band spreading code and is selected.ConnectionThe preamble is transmitted in the slot. At this time, the terminal selection unit 130 is coupled to the first terminal transmission unit 120 and outputs the preamble from the second terminal processor 140 to be transmitted to the base station 200.
[0053]
As a result, in the base station 200, the base station processor 210 receives the preamble transmitted from the terminal apparatus 100 and outputs the preamble to the base station synchronization unit 220. The base station synchronization unit 220 uses the preambles for all usable preamble signatures. The code acquisition is performed and information regarding the acquisition is output to the base station determination unit 230. Then, the base station determination unit 230 determines a preamble signature obtained by receiving information about each preamble signature from the base station synchronization unit 220 and outputs it to the base station transmission unit 240 and the base station transceiver 250. Next, the preamble signature captured by the base station transmission unit 240 is received, a signal corresponding to the captured preamble signature is generated, and the signal is output to the terminal apparatus 100 through the base station processor 210 using the forward common channel. At the same time, the base station transceiver 250 receives the preamble signature captured from the base station determination unit 230 and prepares to receive data transmitted from the terminal apparatus 100 using a band spreading code corresponding to the captured preamble signature. .
[0054]
Meanwhile, the terminal receiver 150 receives the captured display signal transmitted from the base station 200 through the forward common channel via the terminal second processor 140, and captures the transmitted preamble.IsAnd confirms whether or not this is confirmed to the terminal second determination unit 160.
[0055]
At this time, when it is confirmed that the preamble transmitted by the terminal second determination unit 160 is successfully captured, the determination unit 160 disables the terminal first determination unit 110 and the terminal first transmission unit 120, and the terminal second transmission unit. 180 spreads the user information data formatted by the band spreading corresponding to the preamble signature transmitted by the terminal first processor 170 and outputs the user information data to the terminal selection unit 130. The terminal selection unit 130 receives the preamble signature capture display signal from the terminal second determination unit 160, closes the switch to the terminal second transmission unit 180, and transmits the signal to the base station 200 through the terminal second processor 140. It will be. Then, the transmitted data is input to the base station transceiver 250 through the base station processor 210, and the base station transceiver 250 uses the band spreading code previously confirmed through the reverse common channel to perform the data through demodulation and decoding processes. Will be restored.
[0056]
On the other hand, the terminal second determination unit 160 performs transmission.didPreamble signatureButCatchIsWhen it is confirmed that there is no terminal, the terminal first determination unit 110 and the terminal first transmission unit 120 are enabled. That is, the terminal first determination unit 110 randomly selects one preamble signature from the set of preamble signatures, and at the same time,ConnectionSlots are also selected randomly or decisively.
[0057]
Similar to the initial preamble transmission, the terminal first transmission unit 120 generates a preamble that is transmitted by spreading the preamble signature determined using the common band spreading code and is selected.ConnectionslotInTransmit the preamble. At this time, the terminal selection unit 130 is connected to the terminal first transmission unit 120, outputs the preamble to the terminal second processor 140, and transmits this preamble to the base station 200. The operation and the like are repeated with a limited number of repetitions, and the number of repetitions depends on the balance of the traffic loaded on the system and other system conditions.
[0058]
FIG.,An example of the operation | movement of the random connection apparatus of the reverse direction (uplink direction) common channel in a code division multiple access system is shown.
[0059]
First, as shown in FIG. 7, the frame period is 10 ms, and one slot is 1.25 ms.IsAssuming that 8 in one frame periodConnectionThere are slots and one preamble will occupy 1 ms. Therefore,ConnectionSlot is 1ms preamble duration and 0.25ms idle time(Idle time)Consists of. Also, at the base station 200ConnectionThe slot consists of a 1 ms acquisition display signal duration and an idle time of 0.25 ms. Also, for simplicity of explanation, only the case where there are two preamble signatures within one frame duration and only short data is available is considered.
[0060]
Figure7Then the firstConnectionSlot start time (T₀) When the data to be transmitted before, three terminal devices of a certain terminal device have the same transmission slot as a certain preamble signature.randomSuppose you choose At this time, the base station 200 has no preamble to catch, and this is because there is no preamble having a sufficient power level. At this time, the base station 200 transmits only the negative captured display signals of the signal formats # 2 and # 4 and the uncaptured display signals of the signal formats # 1 and # 3. So each terminal devicerandomSelected or givenConnectionIn the slotrandomEach preamble must be retransmitted with a selected preamble signature and an increased power level.
[0061]
The terminal device determines a sufficient power level through open loop power control, andConnectionSlot T₁ In, Each preamble is transmitted with another preamble signature. Capture all 2 preamblesIsA positive or on-acquisition indication signal is received at all terminal devices. Therefore, the terminal deviceConnectionSlot T₂ InEach user information data is transmitted for 10 ms. Of course, the access time for data transmission is T₃Or T₄Can extend.
[0062]
Time slot T₂However, there are cases where two terminal apparatuses transmit a preamble with the same preamble signature, and the base station succeeds in acquiring preamble code synchronization. Therefore, the two terminal devices receive a positive or on-capture display signal corresponding to their preamble signature and transmit their user information data at a predetermined time. In this case, if all the power levels such as the captured preamble are sufficient for the base station to acquire the preamble code, the base station transmits the user information because the receiver synthesizes the multipath signal from other user information data. The data cannot be received successfully. However, if only one preamble has a sufficient power level, the receiver of the base station can synthesize the multipath signal of only one user information data at a sufficient power level and succeed in demodulating the user information data. It is possible to decrypt.
[0063]
FIG. 8 shows an example of the interference signal level of the reverse common channel apparatus according to the present invention. The level indicated by the solid line in FIG. 8 is the level of the conventional reverse common channel.randomThis is the interference level of the connecting device, and the level indicated by the broken line is the reverse common channel according to the present invention.randomThe interference signal level of a connection apparatus is shown. The hatched portion is the reverse common channel according to the present invention compared to the conventional case.randomThe amount of reduction of the interference signal level by the connecting device is shown.
[0064]
As can be seen from FIG. 8, the reverse common channel of the present inventionrandomThe connected device suppresses a large amount of unnecessary data transmission, thereby reducing the interference signal level, increasing the overall capacity, and minimizing the influence on users using other channels, and the preamble. Since data can be retransmitted in units, faster data transmission is possible.
[0065]
Next, a short data transmission service of various sizes will be described using an operation similar to the above-described operation. At this time, if the data length exceeds the predetermined level, a dedicated channel or reservation request is required.randomThe length of data accepted by the connection method is an integral multiple of the existing frame unit, and its type is also limited. For example,randomIf the connection method can accommodate data whose length is four times the frame length, the terminal device must request a dedicated channel assignment or reserved channel for data whose length exceeds four times the frame length.
[0066]
At this time, first, the preamble signature assigned for packet access in the base station must be classified according to the length of the data and recognized by all terminal devices. By doing so, it becomes easy to dynamically assign the preamble signature while considering the traffic balance due to the length of other data.
[0067]
When the terminal device attempts to transmit data on the reverse common channel, these determine data traffic characteristics such as the length of data to be transmitted and the transmission rate. If the terminal device is in accordance with the present inventionrandomWhen data is to be transmitted through the connection method and apparatus, the preamble is transmitted with the preamble signature, and the message signal including the data is transmitted by the capture display. If the terminal device attempts to transmit data through a dedicated channel or a reserved channel, it transmits a preamble with a preamble signature and transmits a message signal for requesting a dedicated channel or a reserved channel based on a captured display signal. For example, the terminal devicerandomIf transmission is to be performed by the connection method and apparatus, the terminal apparatus transmits a preamble with one of the preamble signatures assigned to the 40 ms data, forms four 10 ms frames, and continuously transmits the frames. . And if one of the continuously transmitted frames fails to be transmitted, only one is retransmitted. At this time, the terminal device selects a new preamble signature assigned to the data characteristic to be retransmitted by the same method as described above, and transmits the preamble and the message signal.
[0068]
Next, an operation for requesting channel reservation using a reverse common channel when a terminal device needs to temporarily reserve a channel to transmit intermediate length data will be described.
[0069]
That is, if the base station 200 correctly receives the data for channel reservation, it notifies the corresponding terminal device of the channel reservation, the reserved time, the spreading code, the maximum allowable transmission rate, etc. Data is transmitted within the maximum allowable transmission rate using a band spreading code at the time when the terminal device that received this is reserved. At this time, the base station 200 transmits a power control command (Power Control Command) signal using a forward common channel or a dedicated channel to a reserved terminal device, and performs closed loop power control.
[0070]
When the terminal device intends to change the channel reservation condition during the channel reservation, data related to the channel reservation condition to be changed is transmitted in the same manner as the method of transmitting the preamble for the initial channel reservation. . Also, when the current transmission rate is lower than the maximum allowable transmission rate, the current message transmitted with data related to the channel reservation condition to be changed can be multiplexed. When the channel reservation is completed, the terminal device piggybacks the completion information in the last predetermined field and transmits it to the base station. The base station 200 releases the reserved channel and time, This is notified to all terminal devices.
[0071]
The above-described method for reserving channels of intermediate length data can also be used in application fields such as packet voice services where services are expected in the future.
[0072]
On the other hand, when the transmission data is long or a dedicated channel is required for servicing a voice signal, a method similar to the above-described channel reservation is used. First, from the preamble signature assigned by the terminal device for the dedicated channelrandomOne is selected and transmitted as a preamble, and an acquisition display signal for acquiring a preamble code is received from the base station 200 and data for a dedicated channel request is transmitted. The terminal apparatus determines whether the dedicated channel is allocated from the base station 200.(That is, whether or not allocation is possible)And information on band spreading codes, etc.ButAfter being notified, data will be sent and received using a dedicated channel. Again, like a channel reservation request(Ie, by selecting one of the preamble signatures assigned for channel reservation and transmitting the preamble)The terminal device can transmit data without being limited by the frame length.. MoreoverClosed-loop power control because one or more dedicated channels are assigned to all of the reverse and forward directionsTheIt can be implemented easily.
[0073]
Although the preferred embodiments of the present invention have been illustrated and described above, various changes, modifications, etc. can be made. The detailed description does not limit the scope of the invention, which is defined by the claims.
[0074]
【The invention's effect】
As explained above, the present inventionRadio terminal apparatus, base station, and reverse common channel random connection method in code division multiple access systemAccording to the above, by classifying the preamble signature according to the characteristics of the data, the reverse of various forms such as channel request for dedicated channel assignment, packet access for transmitting short data, intermediate size data, etc. direction(Up direction)The common channel can be used.
[0075]
In addition, the present invention reduces unnecessary data transmission and interference signals, improves network efficiency, and retransmits in units of preambles so that it can quickly approach an appropriate power level and has excellent time delay characteristics. Can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing a network configuration of a code division multiple access system to which the present invention is applied.
FIG. 2 shows the reverse common channel in the code division multiple access system according to the present invention;randomIt is a block diagram which shows the structure of the terminal device and base station in a connection apparatus.
3 is a block diagram showing a configuration of a terminal first determination unit 110 in FIG. 2;
FIG. 4 is according to the present invention.randomIt is explanatory drawing for demonstrating operation | movement between the terminal device and a base station in a connection apparatus.
FIG. 5 is a flowchart showing an example of a connection control procedure of the terminal device according to the present invention.
FIG. 6 is a flowchart showing an example of a connection control procedure of a base station according to the present invention.
FIG. 7 shows the reverse common channel in the code division multiple access system according to the present invention.randomIt is a figure for demonstrating operation | movement of a connection apparatus.
FIG. 8 is a diagram illustrating an example of an interference signal level by a reverse common channel in the code division multiple access system according to the present invention.
FIG. 9 is a diagram illustrating ALOHA data transmission using a reverse common channel in a code division multiple access scheme according to the prior art.
[Explanation of symbols]
100 terminal device
110 terminal first determination unit
111 Signature storage
112 Signature selector
113 Slot selector
114 Power determination unit
120 terminal first transmission unit
130 terminal selector
140 Terminal second processor
150 Terminal receiver
160 Terminal second determination unit
170 Terminal first processor
180 Terminal second transmission unit
200 base station
210 Base station processor
220 Base station synchronization unit
230 Base station determination unit
240 Base station transmission section
250 base station transceiver

Claims (30)

In a wireless terminal device that transmits data to a base station using a code division multiple access method,
Preamble generating means for randomly selecting one preamble signature from a plurality of available preamble signatures classified according to traffic characteristics, and generating a preamble signal using the one randomly selected preamble signature;
Data generating means for generating transmission data for the base station;
Using a specific connection slot randomly selected from a plurality of connection slots , only the preamble signal generated by the preamble generation means is determined based on the state of the transmission path in which the wireless terminal device is placed Preamble transmission means for transmitting to the base station through a reverse common channel with the transmitted power,
The base station receives a preamble capture display signal transmitted to all wireless terminal devices via a forward common channel, and transmits the data to the base station, or is randomly selected. A transmission control means for determining whether to retransmit the preamble signal using the new preamble signature;
A wireless terminal device comprising: The preamble generating means includes
Under the control of the transmission control means, the selected one preamble signature corresponding to traffic characteristics and a connection slot to be used are randomly selected, and at least forward path loss and / or interference transmitted from the base station Terminal determining means for determining the transmission power of the preamble to be transmitted using the signal level;
The wireless terminal device according to claim 1, further comprising: The transmission control means responds to the acquisition display signal transmitted from the base station, and transmits a signal to be transmitted based on the preamble signal generated by the preamble generation means and the data generated by the data generation means. The wireless terminal apparatus according to claim 1, further comprising transmission signal selection means for selecting. The data generating means includes
A terminal first processing unit which is enabled by checking whether data transmission is performed from the transmission control unit, and matches the form of transmitting data to be transmitted;
Terminal second transmission means for receiving data to be transmitted from the terminal first processing means , selecting a code corresponding to a preamble signature, spreading the band, and outputting the spread to the transmission signal selection means;
The wireless terminal device according to claim 3, comprising: The terminal determining means includes
Signature receiving means for receiving and storing information on a preamble signature assigned according to traffic characteristics, transmitted from the base station via a common channel;
Signature selection means for classifying traffic characteristics in consideration of the characteristics of generated data and higher-level requirements, and selecting a preamble signature randomly from the corresponding preamble signature;
A connection slot selection means for selecting a randomly transmitted slot;
Transmission power that determines the transmission power of the preamble signal to be transmitted according to the preset criteria, taking into account any or all of the interference signal level of the base station, the forward path loss, and the previously transmitted preamble power level A determination means;
The wireless terminal device according to claim 2, comprising: In a base station that receives data from the wireless terminal device according to any one of claims 1 to 5, using a code division multiple access method,
Receives a preamble signal transmitted from the wireless terminal device through a reverse common channel, confirms whether a preamble signature is captured, generates a capture confirmation signal corresponding to the captured preamble signature, and forward Preamble signature capturing means for outputting to the wireless terminal device via a common channel;
Base station data transmitting / receiving means for receiving data transmitted from the wireless terminal device using a despreading code generated using the preamble signature captured by the preamble signature capturing means;
A base station characterized by comprising: The preamble signature capturing means includes:
Base station synchronization means for receiving a preamble transmitted via a reverse common channel from the terminal device and performing initial synchronization according to all available preamble signatures;
Inform all time delay characteristic corresponding to the captured preamble signature to the base station data transmitting and receiving means, and a base station transceiving means makes ready to receive the data to be immediately transmitted,
Capture display signal output means for outputting the captured preamble signature;
The base station according to claim 6, comprising: The preamble signature capturing means includes:
Band spread code generating means for notifying the data transmitting / receiving means of the corresponding band spreading code using the captured preamble signature and preparing to receive the data to be transmitted immediately;
The capture display signal generating means for inputting the capture preamble signature from the capture display signal output means and representing the capture preamble signature;
The base station according to claim 6, comprising: The capture display signal output means sets a corresponding time in a preamble signature and outputs a capture display signal as an on-off signal system that transmits the capture display signal only during a time corresponding to the capture preamble signature. The base station according to claim 7. The capture display signal output means outputs a capture display signal as an opposite signal system that sets a corresponding time in a preamble signature and always transmits the capture signal at a time corresponding to all preamble signatures regardless of capture. The base station according to claim 7. The capture display signal output means outputs a capture display signal as an on-off signal system in which a corresponding orthogonal code is assigned to a preamble signature and set by a symbol to be transmitted, and only the orthogonal code corresponding to the capture preamble signature is transmitted. The base station according to claim 7. The acquisition display signal output means sets the symbol to be transmitted by assigning a corresponding orthogonal code to the preamble signature, and displays the acquisition display as an opposite signal system that always transmits symbols corresponding to all preamble signatures regardless of acquisition. The base station according to claim 7 , wherein the base station is configured to output a signal. In a random connection method in which a plurality of terminal devices according to any one of claims 1 to 5 transmit data using a code division multiple access method.
In each terminal apparatus, when the data to be transmitted is generated, each terminal apparatus randomly selects a preamble signature and a connection slot, and transmits each preamble to the base station via a reverse common channel; ,
In the base station, initial synchronization is performed on all preamble signatures transmitted from the terminal apparatus, and a preamble capture display signal corresponding to the captured preamble signature is generated to be transmitted to all terminals through the forward common channel. A terminal-to-terminal transmission step of transmitting;
Transmitting the data to the base station or retransmitting another preamble in response to the preamble capture indication signal received from the base station via a forward common channel;
A reverse common channel random connection method in a code division multiple access system. The base station transmission step randomly selects a preamble signature corresponding to traffic characteristics and a connection slot for transmission in order to transmit a preamble when data to be transmitted is generated, and transmits the preamble according to a method that has already been set. A transmission resource determination step for determining the transmission power of the preamble;
A preamble transmission step for generating and transmitting a preamble signal using the transmission slot, preamble signature, transmission power level, and the like determined in the transmission resource determination step;
The reverse common channel random connection method in the code division multiple access method according to claim 13, further comprising: The transmission resource determining step includes:
A signature information receiving step for receiving and storing information on a preamble signature assigned according to traffic characteristics transmitted from a base station via a common channel;
A traffic characteristic determination step that separates the traffic characteristics, taking into account the characteristics of the data generated and the requirements at the higher levels;
A preamble signature selection step that randomly selects one of the available preamble signatures;
A connection slot selection step for randomly selecting a connection slot for transmission at random; and
Transmission power determination step for determining transmission power of a preamble to be transmitted by open loop transmission power control;
The reverse common channel random connection method in the code division multiple access system according to claim 14, further comprising: The already set method takes into account a part or all of the interference signal level of the base station transmitted from the base station through the common channel, the forward path loss, and the transmission power level transmitted in the previous preamble. The reverse connection common channel random connection method according to claim 14, wherein the transmission power level is adjusted by a predetermined amount. The base station transmission step uses the transmission slot, preamble signature, and transmission power level determined in the transmission resource determination step to spread and transmit a preamble signature using a common band spreading code. 15. The random connection method of a reverse common channel in the code division multiple access system according to claim 14, The base station transmission step includes:
The reverse common channel random connection method in the code division multiple access system according to claim 17, wherein a complex band spread signal is generated using two common band castle spreading codes. Step using the code corresponding to the preamble signature transmitted symbols as used in the forward common channel, code division according to claim 13, characterized in that receiving the preamble acquisition indication signal to the retransmission Random connection method of reverse common channel in multiple access method. Self transmission to the terminal device preamble signatures not caught All the claims, characterized with the counter-base-station transmission step, and said pair terminal transmission step, and said step of retransmitting, already be repeated as many times set 13 A random connection method for a reverse common channel in the code division multiple access system described in 1. The terminal-to-terminal transmission step includes:
An initial synchronization step of performing initial synchronization according to all available preamble signatures by receiving a preamble transmitted from the terminal device via a reverse common channel;
A determination step of confirming whether the initial synchronization is performed from the initial synchronization step, and determining and outputting a captured preamble signature;
A capture display signal transmission step of generating a capture display signal corresponding to the capture preamble signature input from the determination step and outputting the capture display signal to the terminal device;
Input multipath time delay information acquired in the initial synchronization step, generate despreading code using information on acquisition preamble signature input from the determination step, and transmit a reverse common channel from the terminal device A base station data transmission / reception step of receiving transmitted data and receiving it through demodulation and channel decoding processes;
The reverse common channel random connection method in the code division multiple access method according to claim 13, further comprising: The initial synchronization step includes
Enter the preamble transmitted over the reverse common channel from the terminal apparatus, have rows initial synchronization in accordance with any useful preamble signature,
A data reception preparation step for notifying all the time delay characteristics corresponding to the acquisition preamble signature to the base station data transmission / reception step and preparing to receive the data transmitted immediately
Informing the determining step of a capture preamble signature;
The reverse common channel random connection method in the code division multiple access method according to claim 21, wherein: The determining step includes
Using the acquisition preamble signature input from the initial synchronization step, informing the data transmission / reception means of the corresponding code for spreading the band and preparing to receive the data to be transmitted immediately;
An output step of generating a signal only with the acquisition preamble signature and outputting it to the acquisition display signal transmission step;
The reverse common channel random connection method in the code division multiple access method according to claim 21, wherein: The acquisition indication signal transmission step includes four signal systems, that is, a first on-off signal system that sets a corresponding time in a preamble signature and transmits a capture signal only during a time corresponding to the acquisition preamble signature, and a preamble. Set the corresponding time in the signature, and regardless of whether the signal is captured, the first anti-signal system that always transmits the signal according to the captured signal at the time corresponding to all the preamble signatures, and the corresponding orthogonal code is assigned to the preamble signature and transmitted. The second on-off signal system that transmits only the symbols corresponding to the acquisition preamble signature, and assigns the corresponding orthogonal code to the preamble signature and sets the symbols to be transmitted. The second antitrust signal that transmits a symbol corresponding to the preamble signature of Select any one of the signal system of the system, reverse common channel random access method in a code division multimeric connection system according to claim 21, wherein the transmitting to the acquisition indication signal transmission system. The acquisition display signal transmission system includes a method of puncturing an existing forward common channel, a method of dedicating a separate channel having orthogonality to other forward common channels, and orthogonality to other forward common channels. 25. The method for randomly connecting reverse common channels in a code division multiple access system according to claim 24, wherein transmission is carried out by selecting one of the methods dedicated to channels that do not have. In the base station,
Big a channel reservation request requesting專用channel assignment for the transmission of data, and a packet access request for transmitting short data in response to the reservation request and to transmit intermediate size data, reverse common channel The data is transmitted through the forward common channel so that all terminal devices can recognize the characteristics of the data transmitted through the network, and appropriately assign the corresponding preamble signature. 13. A random connection method of reverse common channels in the code division multiple access system according to 13. 27. The code division multiplexing according to claim 26, wherein the packet access request further subdivides and assigns a preamble signature assigned to packet access for transmitting short data according to a length of data transmission. Random connection method of reverse common channel in connection method. For the channel reservation request,
Randomly select one of the preamble signatures assigned for channel reservation from the terminal device and transmit the preamble in the same manner as the packet access, and the base station performs initial synchronization using the preamble transmitted from the terminal device. To inform the acquisition preamble signature to all terminals via the forward common channel,
A terminal device that has transmitted an unacquired preamble signature randomly selects one of the preamble signatures allocated for channel reservation, determines a time slot for transmission, and retransmits the preamble.
The terminal device that has transmitted the acquisition preamble signature transmits data for channel reservation, and then transmits data for reservation to attempt channel reservation.
In the base station, after correctly receiving the data for channel reservation transmitted from the terminal device, inform the corresponding terminal of the channel reservation time and spreading code, transmission rate, etc. using the common channel,
The corresponding terminal transmits the data to be transmitted using a part of or all of the reserved time, spreading code, and transmission rate, and uses the transmission power control command transmitted to the forward channel, and the closed loop transmission power. Control
When the final frame is transmitted, information indicating that the data transmission is completed is included in the data and transmitted to cancel the channel reservation.
The random connection method of a reverse common channel in the code division multiple access system according to claim 26. In order to change the channel reservation condition while using the reserved channel, the data for changing the channel reservation condition is transmitted simultaneously with the data transmission in the same manner as the operation for the packet access or the channel reservation request. A random connection method for a reverse common channel in the code division multiple access system according to claim 28. Upon receiving the preamble capture indication signal transmitted from the base station, a terminal device in which the preamble signature transmitted by itself is not captured, the preamble signature and the slot are re-set at random, and the set amount is transmitted. A retransmission step for retransmitting the power adjusted preamble;
The reverse common channel random connection method in the code division multiple access system according to any one of claims 13 to 29, further comprising:

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