KR100365787B1 - Apparatus and method for communicating channel in cdma communication system - Google Patents

Abstract

In the code division multiple access communication system according to the present invention, the method for calling a call channel communication method comprises the steps of determining a discontinuous reception cycle, and a base station transmitting a call indicator through the call indication channel in response to the determined discontinuous reception mode cycle. And receiving, by the mobile station, a call instruction channel in response to the determined discontinuous reception cycle, and monitoring whether or not the call instruction instruction is called from the call instruction channel, and when the call instruction is received, the mobile station determines the call instruction channel. Receiving a common control physical channel after a predetermined time from the received time point, and demodulating the common control physical channel characterized in that it comprises the step of receiving a call message.

Description

Channel communication apparatus and method of code division multiple access communication system {APPARATUS AND METHOD FOR COMMUNICATING CHANNEL IN CDMA COMMUNICATION SYSTEM}

The present invention relates to a communication apparatus and method of a code division multiple access communication system, and more particularly, to an apparatus and method for paging indicator channel (PICH) communication.

Conventionally, the IS-95-A's paging channel protocol supports both non-slotted mode paging and slotted mode paging. The call channel is divided into paging channel slots having a size of 80 ms. The non-slotted mode paging refers to the terminal receiving a paging message or a control message in all calling channel slots, and the slotted mode paging refers to the terminal. A mobile station receives an upper limit message (call message and control message) only in a specific paging channel slot allocated to the mobile station. Through the slot mode call, limited call channel resources can be efficiently used, and the terminal side can reduce power consumption through an idle sleep function. However, even when the slot mode call is still in the idle sleep state, the terminal wakes up to monitor the call channel and requires 80 ms of power consumption. In addition, additional power consumption, such as wake up before the assigned slot to perform the system reacquisition operation, and operating the interleaver and decoder to check the call message or control message. There are many. In order to reduce the power consumption, a quick paging is used, which means to wake up from the idle state and monitor the call channel only when there is a call message from the base station.

Similarly, the UMTS system also uses a paging indicator channel (PICH) to reduce power consumption of the terminal. The PICH is a fixed rate physical channel having a spreading factor of 256, and a paging indicator (PI) is transmitted through this channel. The PICH is always associated with a secondary common control physical channel (S-CCPCH) to which a paging channel (PCH) transport channel (PCH) is mapped.

1 shows the PICH structure. Referring to FIG. 1, one PICH frame having a length of 10ms consists of 300 bits. Of course, the 288 bits are used to send paging indicators. The remaining 12 bits are not used. N paging channel indicators {PI0, ..., PIN-1} are transmitted in each PICH frame. Where N = 18,36,72, or 144. The mapping process from {PI0, ..., PIN-1} to PICH bits {b0, ... bN-1} is shown in Table 1 below.

Number of PI per frame {N} PI ⁱ = 1 PI ⁱ = 0 N = 18 {b ¹⁶ⁱ , ..., b ^{16i + 15} } = {1,1 ..., 1} {b ¹⁶ⁱ , ..., b ^{16i + 15} } = {0,0 ..., 0} N = 36 {b ⁸ⁱ , ..., b ^{8i + 7} } = {1,1 ..., 1} {b ⁸ⁱ , ..., b ^{8i + 7} } = {0,0 ..., 0} N = 72 {b ⁴ⁱ , ..., b ^{4i + 3} } = {1,1 ..., 1} {b ¹⁶ⁱ , ..., b ^{4i + 3} } = {0,0 ..., 0} N = 144 {b ²ⁱ , b ^{2i + 1} } = {1,1} {b ²ⁱ , b ^{2i + 1} } = {0,0}

If a PI corresponding to a specific terminal is set to 1 in an arbitrary frame, the specific terminal should read the frame corresponding to the related S-CCPCH. However, as shown in FIG. 2, timing is present between the PICH frame and the S-CCPCH frame associated with it. If PI is configured in the PICH frame, a paging message is transmitted through the S-CCPCH, which is transmitted after τ _PICH after the PICH is transmitted. Where τ _PICH is 7680 chips.

In the present UMTS system, as described above, the PICH channel is introduced to support an efficient sleep mode, and the terminal periodically defines the parameter as a parameter by discontinuous reception (hereinafter, referred to as "DRX"). Send down from upper layer to receive calling message. Therefore, the terminal is supposed to check the call message according to the DRX cycle.

However, since the PICH is repeated every frame, when a call is made to a specific terminal, the PI corresponding to the specific terminal is set to '1' and it will be repeatedly transmitted every frame for a certain period. In this case, since the PICH transmits the PICH regardless of the DRX cycle, the overall system efficiency is reduced.

Accordingly, an object of the present invention is to provide a base station communication apparatus and method for transmitting a call indicator (PI) in accordance with a discontinuous reception (DRX) cycle in a code division multiple access communication system.

Another object of the present invention is to provide a terminal communication apparatus and method for monitoring a call indicator according to a discontinuous reception (DRX) frame in a code division multiple access communication system.

In the code division multiple access communication system, a call instruction channel communication method for achieving the above objects includes a process of determining a discontinuous transmission cycle, and a base station transmitting a call indicator through the call instruction channel corresponding to the determined discontinuous transmission mode cycle. And receiving, by the mobile station, the call indication channel in response to the determined discontinuous transmission cycle, and monitoring whether or not the call indication is called by the call indication channel, and when the call indication is received, the mobile station transmits the call. And receiving a common control physical channel after a predetermined time from the time of receiving the indication channel, and demodulating the common control physical channel to receive a call message.

1 is a diagram illustrating a conventional call indication channel structure.

2 shows a PICH frame and its associated S-CCPCH frame.

3 is a diagram illustrating a call indication channel transmission according to the present invention.

4 is a diagram illustrating an operation of a terminal in a sleep mode according to the present invention.

5 is a diagram illustrating a base station procedure according to an embodiment of the present invention.

6 illustrates a mobile station procedure in accordance with an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention describes an effective call indication channel (PICH) transmission scheme and an effective terminal operation scheme for supporting an efficient sleep mode. Also, a receiver structure related to effective call indication channel detection in a UMTS system will be described.

First, referring to the transmission of the call indication channel of the base station, first, since the base station operates according to the discontinuous reception cycle, the base station calls according to the discontinuous reception cycle (= period in which the terminal demodulates the call channel) from the upper layer. Send an indicator (PI). That is, the call indicator transmission is controlled in accordance with the discontinuous reception cycle.

Next, the operation of the terminal in the sleep mode, the call indicator transmitted to the call instruction channel is repeated every frame or discontinuous reception cycle, the terminal operates in accordance with the discontinuous reception cycle in the sleep mode. For example, if a call indicator for a particular terminal is repeated every frame, it is ignored, and the call indicator which wakes up from the sleep state in accordance with the discontinuous reception cycle and receives the call indicator received at the position is monitored. The call indicator is monitored to determine whether there is a call, and when it is determined that there is no call, it sleeps again.

Referring to FIG. 3, an efficient call indication channel transmission scheme in a base station is described as follows.

3 illustrates a case where the number of call indicators is 144 and the call indicator for a specific terminal is'0'-th. Discontinuous receive cycles are determined at higher layers and descend to parameter values. As shown in Table 1, if there is a call when the number of call indicators in one frame is 144, the bit of the call indication channel is determined to be '11' bits. However, when this bit is actually transmitted, it is transmitted by I and Q. As shown in FIG. 3, one complex symbol is transmitted for one call indicator. As described above, when calling a specific terminal using the '0' call indicator, the '0' number symbol is set to '1' in the call indication channel frame. In the existing spec, the call indicator is repeated every frame of the call instruction channel, so the call indicator will be transmitted for a certain period of time. When a call indicator is set in the call indication channel frame, a call message is transmitted through S-CCPCH after τ _PICH after the call indicator is transmitted. In the present invention, since the transmission of the call message is transmitted every discontinuous reception cycle, the call indicator also transmits the discontinuous reception cycle without having to transmit every frame. Referring to FIG. 3, the '0' call indicator transmitted to the call indication channel for a specific terminal is not transmitted during the discontinuous reception cycle period. Applying the same method to any call indicator can increase the system capacity by reducing the interference as a whole. In particular, the smaller the number of call indicators, the greater the effect. Because the number of call indicators in one call instruction channel frame decreases, the number of bits of the call instruction channel mapped to one call indicator increases. In such a case, applying the method described above further increases the effect. Of course, if the terminal is in the sleep state, the terminal will also operate according to the discontinuous reception cycle, and also monitor the call indication channel transmitted according to the discontinuous reception cycle to check whether there is a call. If it is judged that it is demodulated, the S-CCPCH (PCH) is demodulated.

The operation of the terminal in the sleep mode according to the present invention will be described with reference to the accompanying drawings.

Although the call indication channel is transmitted every frame, the terminal operates according to the discontinuous reception cycle. As a result, in order to adapt the operation of the terminal to the discontinuous reception cycle, the position of the call indication channel frame to be monitored when waking from sleep is determined, and the warm-up time and re-acquisition after waking from sleep are determined. The terminal should wake up taking into account the time for acquisition. Of course, in idle mode, not in sleep mode, this time is not required and the call order is monitored only at that time.

5 illustrates a base station procedure according to an embodiment of the present invention.

Referring to FIG. 5, the base station drives a timer in step 501. Here, the timer is a timer synchronized with a reference time obtained when the system is acquired. In step 503, the base station checks whether a discontinuous reception (DRX) cycle has occurred. Whether the discontinuous reception cycle has been performed should be checked for each of the specific terminals. If the discontinuous reception cycle is determined, the base station proceeds to step 505. Otherwise, the base station waits until the discontinuous reception cycle. In this case, the discontinuous reception cycle is examined at a predetermined time earlier than the actual cycle time in consideration of the processing delay caused by the call message transmission. On the other hand, after detecting that the discontinuous reception cycle has been reached, the base station checks whether a call message to be transmitted to a specific mobile station has occurred in step 505. In this case, if the call message occurs, the base station proceeds to step 507 and sets the call indicator (PI) corresponding to the specific mobile station to "1". Otherwise, the base station proceeds to step 509 and corresponds to the specific mobile station. Set the call indicator to "0". Herein, the call indicator being set to "1" means that there is a call message to be transmitted to the specific mobile station. After setting the call indicator, the base station proceeds to step 511 and transmits a call order channel frame including the set call indicator information to the terminals. In step 513, the base station transmits a call message to the specific mobile station through a second common control physical channel.

6 illustrates a mobile station procedure according to an embodiment of the present invention.

Referring to FIG. 6, the mobile station drives a timer in step 601. Here, the timer is a timer synchronized with a reference time obtained when the system is acquired. On the other hand, it is assumed that the mobile station is in a sleep state. In step 603, the mobile station checks whether a discontinuous reception (DRX) cycle has occurred. Here, if it is determined that the discontinuous reception cycle has been reached, the base station proceeds to step 605, otherwise, the base station waits until the discontinuous reception cycle. After detecting that the transmit / receive cycle has been reached, the mobile station demodulates a call indication channel in step 605 to receive and analyze a PICH frame. The mobile station then checks in step 607 whether the corresponding call indicator PI among the call indicators included in the frame is set to " 1 ". If the call indicator is set to " 1 ", the mobile station proceeds to step 609; otherwise, terminates. Herein, when the call indicator is set to "1", it means that the call message is received later. Accordingly, the mobile station demodulates the second common control physical channel after a predetermined time elapses in step 609 to receive a call message.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention transmits the call indicator transmitted through the call instruction channel (PICH) in accordance with a predetermined discontinuous transmission cycle, and the terminal monitors whether or not the call indicator of the call indicator according to the discontinuous transmission cycle, Capacity reduction can be achieved by reducing the call indicators sent per frame.

Claims (4)

A call indication channel communication apparatus of a code division multiple access communication system, A base station for transmitting a call indicator transmitted through a call indication channel based on a predetermined discontinuous transmission cycle; And a terminal for checking whether or not the call indicator is called in response to the predetermined discontinuous transmission cycle, and receiving and demodulating a common control physical channel after a predetermined time when the call indicator is received. A method for transmitting a call indication channel of a base station in a code division multiple access communication system, Determining the discrete transmission cycle, And transmitting a call indicator through a call indication channel in response to the determined discontinuous transmission mode cycle. A method for receiving a call indication channel of a terminal in a code division multiple access communication system, Determining the discrete transmission cycle, Receiving a call instruction channel in response to the determined discontinuous transmission cycle, and monitoring whether or not the call instruction instruction is called from the call instruction channel; And receiving a common control physical channel after a predetermined time from when the call instruction channel is received when the call instruction is received, and demodulating the common control physical channel to receive a call message. A call indication channel communication method in a code division multiple access communication system, Determining the discrete transmission cycle, Transmitting, by a base station, a call indicator through a call indication channel in response to the determined discontinuous transmission mode cycle; Receiving, by the mobile station, the call instruction channel in response to the determined discontinuous transmission cycle, and monitoring whether or not the call instruction instruction is called from the call instruction channel; And when the call instruction is received, the mobile station receives a common control physical channel after a predetermined time from when the call instruction channel is received, and demodulates the common control physical channel to receive a call message. Way.