KR101624312B1 - System and method for power allocation of downlink code-channels for voice services in high-speed wireless communication networks - Google Patents

Abstract

In the present invention, when a base station provides a voice packet service to a user terminal, the base station checks a channel state based on CQI information transmitted from the user terminal, calculates a transmission power gain, To a method and system for downlink code channel power allocation for voice services, wherein power is allocated to a downlink code channel by adding or subtracting gain.

A base station according to the present invention includes: a communication unit for communicating with a user terminal; A power allocator for allocating downlink code channel power for voice packet transmission to the user terminal; A scheduler for scheduling a voice packet using the allocated downlink code channel power; And comparing the amount of transmittable data with the reference size ( _MQ ) of the voice packet based on the channel quality indicator (CQI) information transmitted from the user terminal when the voice packet service is provided to the user terminal, If the amount of data is larger than a reference size ( _MQ ) of the voice packet, and if the amount of data is larger than the reference size ( _MQ ) of the voice packet, In response to the control signal.

According to the present invention, it is possible to efficiently use downlink radio resources by preventing inefficient radio resource allocation that may occur when voice service is supported through HSDPA technology. Also, by using the power allocation method proposed by the present invention, it is possible to transmit a voice packet with the optimal transmission power according to the channel state of the terminal. Particularly, considering that the size of the voice packet is rather small, in most channel environments, the packet can be transmitted with lower transmission power than the conventional method. Since the downlink power can be used for high-speed data services other than voice, the overall transmission speed of the downlink can be improved.

Base station, HSDPA, CQI, voice, packet, downlink, code channel, power, allocation

Description

Technical Field [0001] The present invention relates to a method and a system for a downlink code channel power allocation for a voice service,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for downlink code channel power allocation for voice service in a High Speed Downlink Packet Access (HSDPA) system. More specifically, when a base station provides a voice packet transmission service to a user terminal, The amount of transmittable data is compared with the reference size (M _Q ) of the voice packet based on the channel quality indicator (CQI) information received from the terminal, _Q ), and to transmit at a power lower than the reference power if the amount of transmittable data is larger than the reference size (M _Q ) of the voice packet, the downlink code channel power for voice service Assignment method and system.

HSDPA (High-Speed Downlink Packet Access) has adopted various technologies that can improve the downlink transmission rate up to 14.4Mbps in the existing WCDMA system.

In HSDPA technology supporting high-speed transmission rate, 16-QAM (4 bits / symbol) which increases the number of transmission bits per symbol is introduced as compared with the conventional QPSK, and the modulator method and channel coding rate And AMC (Adaptive Modulation & Coding) technology that dynamically changes the frequency.

In order to quickly recover an error occurring in the physical layer, HARQ (Hybrid ARQ) technology combining FEC (Forward Error Correction) and ARQ (Automatic Repeat request) is applied and a plurality of channelization codes (Up to 15).

In addition, the TTI is shortened to 2 ms, and performs a packet scheduling function capable of freely allocating downlink radio resources on a per TTI basis based on downlink quality information transmitted from the UE.

In HSDPA, the complexity of the system is reduced by fixing the spreading factor (SF) to 16 for downlink transmission. The various transmission rates of data are supported by changing the number of codes used and the Modulation and Coding Scheme (MCS) used in each code channel. The maximum transmission rate of 14.4 Mbps that can be supported by the HSDPA system corresponds to the case where 15 code channels of the SF 16 are used and the 16 QAM modulation scheme is used in each code channel.

The HSDPA terminal reports the channel quality indicator (CQI) corresponding to the downlink channel state once every 2 ms through the uplink to request an appropriate data transmission rate matching the downlink state. The CQI values are defined in 30 steps, and information such as the transmission block size, the number of allocated codes, and the modulation technique are defined for each step. The higher the CQI, the better the downlink quality.

An adaptive multi-rate (AMR) voice codec used in a general mobile communication system has an ON section in which a voice packet is generated and an OFF section in which a voice packet is not generated in consideration of voice generation characteristics. Normally, ON duration is about 1 second on average, and voice packets are constantly generated by 244 bits every 20 ms. OFF interval is about 1 second on average, and a 39-bit SID (silence insertion descriptor) packet including background noise is generated at intervals of 160 ms without outputting voice information.

Recently, attempts have been made to increase the downlink voice capacity by transmitting voice information using HSDPA technology. In the conventional method, since a downlink channel for voice is dedicatedly allocated, a corresponding channel can not be allocated to another terminal even if data transmission is not performed. However, when voice packets are transmitted through HSDPA technology, terminals can share wireless resources So that the downlink capacity can be improved. In particular, since the voice packet is generated by repeating the ON and OFF sections, if the multiplexing is performed effectively, the performance can be improved by about two times as compared with the method using dedicated resources.

However, the HSDPA transmission scheme is not suitable for transmission of voice packets. If the channel state of the terminal is not good, the voice packet is not properly transmitted and the delay time becomes long, so that the packet can be discarded. On the other hand, when the channel state of the terminal is good, a large amount of resources are allocated as compared with the data to be transmitted, so that the utilization efficiency of radio resources is lowered.

HSDPA is a technology for general packet data service rather than optimized for voice service. Therefore, the basic transmission unit of the downlink does not exactly coincide with the size of the voice packet. For example, if the downlink quality of a particular terminal is not good (small CQI), but the base station decides to transmit a voice packet for the terminal, the voice packet should be divided and transmitted without being able to transmit one voice packet at a time. On the other hand, if the CQI is sufficiently large, the BS can sufficiently transmit the voice packet, but since the BS transmits an excessive number of bits compared to the size of the voice packet, most of the transmission block may include padding bits . That is, unnecessarily large amounts of data can be transmitted.

Accordingly, the BS can determine an appropriate data size based on the CQI value reported by the MS. However, if the amount of transmittable data is smaller or larger than the reference size ( _MQ ) of the voice packet, There is a problem to waste.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide an apparatus and method for providing a voice packet service to a user terminal, by the comparison with the standard size (M _Q), transmittable data amount is based on the size of smaller than standard size of a voice packet (M _Q) and transmitted to the higher power than the reference power, the transmittable amount of data the audio packet (M _Q , The base station and the downlink code channel power allocation method for the base station and the downlink code channel power allocation method for the voice service are provided.

According to another aspect of the present invention, there is provided a system for allocating a downlink code channel for a voice service, the system comprising: a downlink channel allocation unit for allocating a downlink channel to a downlink channel based on channel quality indicator (CQI) A base station for calculating a transmission power gain (DELTA) by checking a state and adding or reducing the calculated transmission power gain (DELTA) to the reference power and transmitting the voice packet using the allocated power; And a user terminal receiving the voice packet with the transmission power gain (?) Added to the reference power or the reduced power from the base station after transmitting the channel quality indicator (CQI) information to the base station.

According to another aspect of the present invention, there is provided a base station including: a communication unit for communicating with a user terminal; A power allocator for allocating downlink code channel power for voice packet transmission to the user terminal; A scheduler for scheduling a voice packet using the allocated downlink code channel power; And comparing the amount of transmittable data (M) with a reference size (M _Q ) of the voice packet based on the channel quality indicator (CQI) information transmitted from the user terminal when the voice packet service is provided to the user terminal, If the amount of transmittable data M is less than a reference size M _Q of the voice packet, the mobile station transmits at a higher power than the reference power, and if the amount of transmittable data M is greater than a reference size M _Q of the voice packet And controls the transmission of the voice packet at a power lower than the reference power.

In addition, when providing the voice packet service, the control unit allocates a transmission power gain (?) To the reference power for the downlink data channel through the power allocation unit or a reduced power.

In addition, the control unit allocates the remaining transmission power allocated to the voice packet to another packet data service, and controls the transmission rate to be increased.

The power allocator may allocate power added with a transmission power gain (?) To a reference power if the amount of transmittable data (M) is smaller than a reference size (M _Q ) of a voice packet, (M) is larger than the reference size (M _Q ) of the voice packet, the transmission power gain (?) Is reduced to the reference power.

The transmission power gain? Is calculated by dividing the reference size (M _Q ) of the voice packet by the amount of transmittable data (M) and taking a logarithm value.

According to another aspect of the present invention, there is provided a downlink code channel power allocation method for a voice service in a system including a user terminal and a base station, ) The user terminal transmitting channel quality indicator (CQI) information to the base station; (b) checking the channel state based on the channel quality indicator (CQI) information of the base station; (c) calculating a transmit power gain (?) using the transmittable data amount (M) and a reference size (M _Q ) of a voice packet; And (d) allocating power of the downlink code channel by adding or decreasing the transmission power gain? To the reference power.

According to another aspect of the present invention, there is provided a downlink code channel power allocation method for a voice service of a base station, the downlink code channel power allocation method for a voice service of a base station providing a voice packet service to a user terminal (A) receiving the channel quality indicator (CQI) information from the user terminal; (b) calculating transmission power gain (?) based on the channel quality indicator (CQI) information; (c) comparing the transmittable amount of data (M) contained in the channel quality indicator (CQI) information and a reference magnitude (M _Q) of the voice packet; And (d) allocating power of the downlink code channel by adding or subtracting the transmission power gain? To the reference power according to the comparison result.

In the step (b), the transmit power gain (?) Is calculated by dividing the reference size (M _Q ) of the voice packet by the amount of transmittable data (M) and taking a log.

In the step (d), if the amount of transmittable data M is smaller than the reference size M _Q of the voice packet, the transmit power gain? Is added to the reference power.

In the step (d), if the amount of transmittable data M is larger than the reference size M _Q of the voice packet, the transmit power gain? Is allocated to the reference power.

In the step (d), the transmission power allocated to the voice packet is allocated to another packet data service to increase the transmission speed.

In the step (d), a transmission power gain? Is added to the reference power for the downlink data channel or a reduced power is allocated to the reference power.

According to another aspect of the present invention, there is provided a method for allocating a downlink code channel for a voice service of a base station providing a voice packet service to a user terminal, the method comprising the steps of: (a) Receiving the channel quality indicator (CQI) information from a terminal; (b) calculating transmission power gain (?) based on the channel quality indicator (CQI) information; (c) comparing the transmittable amount of data (M) contained in the channel quality indicator (CQI) information and a reference magnitude (M _Q) of the voice packet; (d) allocating power of the downlink code channel by adding or subtracting the transmission power gain (?) to the reference power according to the result of the comparison; and Record in the program.

According to the present invention, it is possible to efficiently use downlink radio resources by preventing inefficient radio resource allocation that may occur when voice service is supported through HSDPA technology.

Also, by using the power allocation method proposed by the present invention, it is possible to transmit a voice packet with the optimal transmission power according to the channel state of the terminal.

Particularly, considering that the size of the voice packet is rather small, in most channel environments, the packet can be transmitted with lower transmission power than the conventional method.

Since the downlink power can be used for high-speed data services other than voice, the overall transmission speed of the downlink can be improved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In order to support HSDPA in the present invention, additional physical channels are required unlike the conventional WCDMA. (HS-PDSCH), a High-Speed Shared Control Channel (HS-SCCH), a high-speed dedicated physical channel And a High Speed-Dedicated Physical Control Channel (HS-DPCCH).

The physical channel HS-PDSCH means each code channel using SF16, and up to 15 HS-PDSCHs can be used in HSDPA. The modulation scheme can use QPSK or 16QAM according to the downlink state, and the channel coding rate can be generated with various values based on a 1/3 turbo code. The transmission time interval (TTI), which is the transmission period of the data, is shortened to 2 ms, and efficient and fast transmission is possible according to the channel state of each terminal. In addition, a hybrid automatic repeat request (HARQ) scheme is used for data transmission, thereby facilitating recovery of lost data during transmission. The difference between HARQ and the existing ARQ scheme is that previously transmitted data is not discarded but is combined with newly transmitted data and used for decoding.

Also, in the HSDPA system, power control is not performed on the HS-PDSCH. All base stations transmit data using almost all of the power allocated for HSDPA. That is, power control is not performed on the downlink. For this reason, the downlink transmission rate control employs adaptive modulation and coding (AMC), which selects an appropriate modulation and coding scheme considering channel conditions of each terminal. In addition, to reduce radio resource waste, hard handover is used in which only one base station receives data without supporting soft handover.

1 is a diagram showing the structure of a subframe of the HS-PDSCH used in the present invention.

Referring to FIG. 1, one subframe in the HS-PDSCH can be regarded as one TTI, and has a length of 2 ms and three time slots in the interior. The amount of data that can be transmitted is determined according to the state of the downlink, the modulation and coding scheme selected, and the number of codes, and the data is transmitted in each time slot. Referring to FIG. 1, when 16QAM is used, it can be seen that it can include about twice data as compared with QPSK.

Meanwhile, the HS-SCCH includes various control information used when the UE successfully retrieves data received through the HS-PDSCH. In particular, the channel transmits HS-PDSCH decoding information by two time slots before the HS-PDSCH so that the UE can receive the HS-PDSCH decoding information in advance. Two kinds of information are transmitted to the HS-SCCH. In the first time slot, information on the HS-PDSCH code information (starting position of the used code and the number of codes) and the modulation scheme are transmitted. In the second and third time slots, Includes various information such as whether the packet transmitted through the HS-DSCH is a new packet, a transport block size, and a redundancy version for HARQ. In particular, the first slot and the third slot include identification information for indicating a terminal receiving the HS-PDSCH.

If HS-SCCH information is not received, HS-SCCH information is very important because data received via the HS-PDSCH can not be recovered. Therefore, it is necessary to transmit using a relatively high transmission power, and a terminal at the cell boundary must also be able to receive the HS-SCCH. According to the standard, a terminal must be able to observe up to four HS-SCCHs at the same time. For reference, the number of HS-SCCHs is equal to the number of terminals that can simultaneously receive data every TTI.

Then, the HS-DPCCH transmits uplink ACK / NAK information and CQI (Channel-Quality Indication) information for assisting the operation of the HS-DSCH. The HS-DPCCH is configured with three time slots. In the first time slot, ACK / NAK information indicating the success of the received data is transmitted in the second and third time slots, The CQI information indicating the quality of the downlink is transmitted. One HS-DPCCH is set per terminal.

Meanwhile, in the HSDPA of the present invention, a terminal transmits a CQI value corresponding to a downlink channel state to a base station (BS) every TTI (2 ms) through an uplink HS-DPCCH to request an appropriate data transmission rate suited to its downlink state. . CQI values are defined in 30 steps, and information such as transmission block size, number of allocated codes, modulation scheme, and HS-PDSCH output level control are defined for each step. The CQI information transmitted by all the terminals in the cell is used as a very important criterion by which the HSDPA scheduler located in the base station determines the transmission order and amount of data.

2 is a diagram illustrating a CQI value and a meaning of a CQI value of a terminal corresponding to category 10 having the best performance among the terminals supporting HSDPA of the present invention. Other categories of terminals have similar CQIs.

As can be seen from FIG. 2, the CQI transmitted by the terminal to the base station may be the amount of data that the terminal can receive. For example, when CQI = 25, the UE can receive 10 HS-PDSCH codes at the same time and has a channel state capable of supporting 16QAM. Since the amount of data that can be received through this is 14411 bits, the transmission speed can support 7.2Mbps (= 14,411 bits / 2ms). The base station can determine the downlink channel status of the terminals according to the received CQI and transmits an appropriate amount of data within a range not exceeding the CQI reported by the terminal. However, for the sake of convenience of system implementation, if possible, downlink resources are allocated in the same manner as the CQI reported by the UE.

In order to support the voice service in the HSDPA according to the embodiment of the present invention, a fixed-size packet such as a voice packet must be transmitted through the HS-PDSCH. 960 bits can be transmitted when QPSK is used, and 1920 bits can be transmitted when 16QAM is used for a 2 ms TTI, which is a basic transmission unit of the HS-PDSCH. Considering that the size of a voice packet generated every 20 ms is about 244 bits in a voice service, even if an additional coding process is added, a base station can sufficiently transmit a voice packet by using one HS-PDSCH for 2 ms.

Based on the CQI delivered to the base station by the terminal, The transmission block size indicated in FIG. 2 may be a voice packet before being decoded. The CQI has a total of 30 values except 0, and the CQI which can not support 244 bits is limited to 3 cases of 1, 2, and 3. All other CQIs can support more than 317 bits even if only one QPSK and HS-PDSCH code is used.

3 is a block diagram illustrating the overall configuration of a downlink code channel power allocation system for voice service according to an embodiment of the present invention.

3, a downlink code channel power allocation system 300 for voice service according to the present invention includes a user terminal 310, a communication network 320, and a base station 330.

The user terminal 310 transmits a channel quality indicator (CQI) information to the base station 330 and then receives a voice packet with a transmission power gain? do.

The communication network 320 includes a cdma2000 1x, a cdma2000 1x EV-DO, a WCDMA network, a TD-SCDMA, an HSPA network, and the like as a mobile communication network.

The base station 330 checks the downlink channel state based on the channel quality indicator (CQI) information received from the user terminal 310 to provide the transmission power gain? And transmits the voice packet to the user terminal 310 using the allocated power by adding or reducing the transmission power gain? To the reference power.

4 is a diagram illustrating a general HS-PDSCH power allocation method.

Referring to FIG. 4, all terminals in a cell receive a common pilot channel ( _CPICH ) transmitted by a base station at a constant power ( _CPICH ). Since the terminal knows the value of P _CPICH from the initially acquired system information, it can grasp the state of the downlink channel from the received power of the received CPICH. In addition, the UE can calculate a CQI suitable for itself based on the transmission power relationship between the CPICH and the HS-PDSCH.

On the other hand, the HSDPA base station does not perform power control for the HS-PDSCH. If the power allocated by the base station for HSDPA is referred to as P _HSDPA and simultaneously with N channelization codes, each HS-PDSCH uses the transmit power of P _HSDPA / N. The base station determines the amount of data M to be transmitted to the mobile station based on the CQI reported by the mobile station. CQI and M may vary because the channel state may be different depending on each terminal.

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

5, a base station 330 according to the present invention includes a communication unit 510, a power allocation unit 520, a scheduler 530, and a control unit 540.

The communication unit 510 communicates with the user terminal 310 through the communication network 320.

The power allocation unit 520 allocates the downlink code channel power for voice packet transmission to the user terminal 310.

The scheduling unit 530 schedules voice packets using the allocated downlink code channel power.

The control unit 540 transmits the amount of transmittable data M to the base station of the voice packet based on the channel quality indicator (CQI) information transmitted from the user terminal 310, when providing the voice packet service for the user terminal 310. [ size (M _Q) as compared with, transmittable amount of data (M) the standard of less than the standard size (M _Q) of the voice-packet transmission with higher power than the reference power, and can transfer the amount of data (M) the audio packet If it is larger than the size ( _MQ ), control is performed so that the voice packet is transmitted at a power lower than the reference power.

Since the size of the voice packet generated at the base station 330 in the 20 ms cycle is about 244 bits, the size of the voice packet is about 300 bits even if header information for HSDPA transmission is added. An appropriate CQI value for transmitting the thus generated transport block denoted Q, and wherein the transport block size, i.e., a reference size of a voice packet will be denoted as M _Q. In the example of FIG. 2, Q = 4 would be appropriate. Based on the CQI value reported by an arbitrary k-th terminal, the base station can determine an appropriate data size.

In addition, the control unit 540 allocates the transmission power gain? To the reference power for the HS-PDSCH code channel through the power allocation unit 520 when the voice packet service is provided.

At this time, if the amount of transmittable data M _k is smaller than the reference size M _Q of the voice packet for the k-th terminal, the power allocation unit 520 allocates the power with the transmission power gain Δ _k added to the reference power And if the amount of transmittable data M _k is larger than the reference size M _Q of the voice packet, the transmit power gain? _K is reduced to the reference power.

Here, the transmit power gain as shown in Equation 1 (Δ _k) is divided based on the size (M _Q) of the voice packet to the transmittable data amount (M _k) is calculated by taking the log.

However, the transmission power gain (? _K ) added to the reference power does not necessarily have to be calculated by dividing the reference size (M _Q ) of the voice packet by the amount of transmittable data (M _k ) and taking the log. It can be set up considering various aspects in accordance with the modulation method or the purpose of the developer.

Then, the control unit 540 allocates the remaining transmission power to the other packet data service and allocates the remaining transmission power to the voice packet so as to increase the transmission speed.

6 is a flowchart illustrating a downlink code channel power allocation method for voice service according to an embodiment of the present invention.

Referring to FIG. 6, the user terminal 310 transmits channel quality indicator (CQI) information to the base station 330 (S610).

The user terminal 310 receives a CPICH (common pilot channel) transmitted by the base station 330 at a constant power ( _CPICH ). Since the user terminal 310 knows the value of the P _CPICH from the initially acquired system information, the user terminal 310 grasps the state of the downlink channel from the received power of the CPICH received by the user terminal 310, and also determines the transmission power relationship between the CPICH and the HS- Lt; RTI ID = 0.0 > CQI < / RTI > Then, the base station 330 transmits the calculated CQI information to the base station 330.

Accordingly, the base station 330 checks the channel state based on the channel quality indicator (CQI) information (S620).

Next, the base station 330 calculates the transmission power gain? _K using Equation 1 using the amount of transmittable data M _k and the reference size M _Q of the voice packet in operation S630.

Then, the base station 330 allocates power of the downlink code channel by adding or decreasing the transmission power gain ( _k ) to the reference power (S640).

The base station 330 transmits the voice packet to the user terminal 310 using the allocated power (S650).

7 is a diagram illustrating a power allocation method of an HS-PDSCH according to an embodiment of the present invention.

Referring to FIG. 7, in contrast to the conventional method shown in FIG. 4, the HS-PDSCH is not transmitted to the PHSDPA / N, which is a constant reference power, _K ) is added and transmitted.

However, the CQI determined by the user terminal 310 is not changed. This is because the CQI reported by the UE 310 is based on CPICH instead of HS-PDSCH. The present invention assists the user terminal 310 in maintaining the state of the radio channel according to the level of the voice packet received.

At this time, the transmission power gain (? _K ) added to the reference power does not necessarily have to be set to 10 log (M _Q / M _k ). It can be set in consideration of various aspects in accordance with the modulation method or the purpose of the developer.

8 is a flowchart illustrating a downlink code channel power allocation method for a voice service of a base station according to the present invention.

Referring to FIG. 8, the base station 330 according to the present invention first receives channel quality indicator (CQI) information from the user terminal 310 (S810).

Then, the base station 330 calculates a transmission power gain? _K according to Equation (1) based on CQI information (S820).

That is, the base station 330 divides the reference size M _Q of the voice packet by the amount of transmittable data M _k and takes a log to calculate the transmit power gain Δ _k .

The base station 330 then compares the amount of transmittable data M _k included in the channel quality indicator (CQI) information with the reference size M _Q of the voice packet (S830).

Then, the base station 330 allocates the power of the downlink code channel by adding or decreasing the transmission power gain ( _k ) to the reference power according to the comparison result. At this time, the base station 330 allocates the transmission power gain ( _k ) to the reference power for the HS-PDSCH code channel with the power added or reduced.

Here, if the amount of transmittable data M _k is smaller than the reference size M _Q of the voice packet (M _k <M _Q ) (S 840 - Yes), the base station 330 transmits the transmit power gain _K ) is allocated (S850).

That is, when the amount of transmittable data M _k is smaller than the reference size M _Q of the voice packet, it is difficult for the downlink channel state to transmit one voice packet. Two or more HS-PDSCHs can be used, but a single terminal may monopolize radio resources shared with other terminals. When transmitting data of M _Q using only one code channel, it is appropriate to transmit E _b / N ₀ (E _b : bit energy, N ₀ : noise spectral density) to P _HSDPA / The transfer of the data can be regarded as a failure. Therefore, it is necessary to increase the transmission power (P _HS-PDSCH ) of the _HS-PDSCH to be higher than the reference power P _HSDPA / N in order to transmit data of M _Q size. From the viewpoint of E _b / N ₀ , M _Q bits are transmitted using a channel capable of transmitting M _k bits, so that Δ _k = 10 log (M _Q / M _k ) [dB] is added to the reference power.

However, the transferable data amount (M _k) is greater than the reference magnitude (M _Q) of the voice packet (M _k> If the M _Q) (S840- NO), the transmission power gain (Δ _k) to the reference power reduction Power is allocated (S855).

That is, when the amount of transmittable data M _k is larger than the reference size M _Q of the voice packet, the base station 330 can transmit a large amount of data to the user terminal 310 because the downlink channel state is good . However, since the amount of data larger than M _Q is unnecessary information, the base station 330 can transmit at a lower power. From the E _b / N ₀ side, it transmits M _Q bits using a channel that can send M _k bits, so it is reduced by Δ _k = 10 log (M _Q / M _k ) [dB] than the reference power.

Next, the base station 330 transmits the voice packet to the user terminal 310 using the power allocated to the HS-PDSCH code channel in the above-described procedure (S870).

Particularly, considering that the size of the voice packet is rather small, in most channel environments, the packet can be transmitted with lower transmission power than the conventional method.

Since the downlink power can be used for high-speed data services other than voice, the overall transmission speed of the downlink can be improved.

9 is a diagram illustrating an internal structure of a base station that allocates transmission power saved in a voice service to a data service according to an embodiment of the present invention.

9, the base station 330 receives the CQI from the user terminal 310 via the CQI receiver 910 and determines a transmission power suitable for receiving voice packets of the corresponding terminal through the voice transmission power calculator 920 do.

At this time, if the CQI reported by the user terminal 310 is not suitable for transmitting a voice packet (M _k <M _Q ), the base station 330 does not transmit a voice packet to the corresponding terminal.

In the base station 330, the voice transmission power calculator 920 receives available transmission power and power setting parameters from the physical channel transmission power allocation unit 940 and determines the transmission power of each physical channel supporting voice service .

The physical channel transmission power allocation unit 940 allocates the transmission power of the voice service, and then transmits the transmission power information saved in the process to the data transmission power calculation unit 930.

The data transmission power calculator 930 finally determines the transmission power of each physical channel supporting the data service.

Meanwhile, a downlink code channel power allocation method for a voice service of a base station providing a voice packet service to a user terminal according to the present invention comprises the steps of: (a) receiving the channel quality indicator (CQI) information from the user terminal; ; (b) calculating transmission power gain (?) based on the channel quality indicator (CQI) information; (c) comparing the transmittable amount of data (M) contained in the channel quality indicator (CQI) information and a reference magnitude (M _Q) of the voice packet; (d) allocating power of the downlink code channel by adding or subtracting the transmission power gain (?) to the reference power according to the result of the comparison; and It can be recorded as a program on a computer-readable medium such as a CD or a USB memory.

As described above, according to the present invention, when a base station provides a voice packet service to a user terminal, the amount of transmittable data (M) is stored in a voice packet based on channel quality indicator (CQI) information transmitted from the corresponding user terminal based on the size compared to the (M _Q), the transmittable amount of data (M) is smaller than the reference size (M _Q) of the voice-packet transmission with higher power than the reference power, and can transfer the amount of data (M) the audio packet A downlink code channel power allocation method and system for voice service, and a base station and a downlink code channel power allocation method thereof, which are designed to transmit at a power lower than the reference power if it is larger than the reference size ( _MQ ).

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It must be done. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

The present invention can be applied to an HSDPA system that allocates power of a downlink code channel for voice service.

In addition, the present invention can be applied to a base station that allocates downlink resources by reflecting characteristics of voice traffic, and can apply CQI information to a base station to which a voice packet is transmitted after transmitting the CQI information.

In addition, the present invention can be applied to a communication system that can use the reduced downlink power for high-speed data services other than voice by transmitting voice packets with optimal transmission power.

1 is a diagram showing the structure of a subframe of the HS-PDSCH used in the present invention.

2 is a diagram illustrating a CQI value and a meaning of a CQI value of a terminal corresponding to category 10 having the best performance among the terminals supporting HSDPA of the present invention.

3 is a block diagram schematically showing the overall configuration of a downlink code channel power allocation system for voice service according to an embodiment of the present invention.

4 is a diagram illustrating a general HS-PDSCH power allocation method.

5 is a block diagram schematically illustrating functional blocks of a base station according to an embodiment of the present invention.

6 is a flowchart illustrating a downlink code channel power allocation method for voice service according to an embodiment of the present invention.

7 is a diagram illustrating a power allocation method of an HS-PDSCH according to an embodiment of the present invention.

8 is a flowchart illustrating a downlink code channel power allocation method for a voice service of a base station according to the present invention.
9 is a diagram illustrating an internal structure of a base station that allocates transmission power saved in a voice service to a data service according to an embodiment of the present invention.

Description of the Related Art

300: Downlink code channel power allocation system 310:

320: communication network 330: base station

510: communication unit 520: power allocation unit

530: Scheduler 540:

Claims (14)

delete A communication unit for communicating with a user terminal; A power allocator for allocating a downlink code channel power for transmitting a voice packet of a voice packet service to a user terminal; A scheduler for scheduling a voice packet using the allocated downlink code channel power; And (M) and a voice quality indicator (CQI) received from the user terminal when the voice packet service is provided to the user terminal, as compared to standard size (M _Q), and the transmittable amount of data (M) is assigned a higher power than the reference power is smaller than the standard size (M _Q) of the voice packet as the power of the downlink code channels, the transmittable amount of data (M) the controls to allocate a lower power is greater than the reference power than the standard size (M _Q) of the voice packet as the power of the downlink code channel, is assigned to voice packets and the other the remaining power A control unit for allocating the packet data service to the packet data service; / RTI &gt; 3. The method of claim 2, The control unit allocates a transmission power gain (?) To the reference power for the HS-PDSCH (HS-PDSCH) code channel through the power allocation unit And the base station. 3. The method of claim 2, Wherein the power allocator allocates a power to which the transmission power gain (?) Is added to the reference power if the amount of transmittable data (M) is smaller than a reference size (M _Q ) of the voice packet, ) Is greater than a reference size (M _Q ) of the voice packet, the transmission power gain (?) Is reduced to the reference power. 5. The method of claim 4, Wherein the transmission power gain (?) Is calculated by dividing a reference size (M _Q ) of a voice packet by the amount of transmittable data (M) and taking a log. delete delete A method for allocating a downlink code channel for a voice service of a base station providing a voice packet service to a user terminal, Receiving channel quality indicator (CQI) information from the user terminal; Checking the amount of transmittable data (M) based on the channel quality indicator (CQI) information and comparing the amount of transmittable data (M) with a reference size (M _Q ) of a voice packet of the voice packet service; If the amount of transmittable data (M) is smaller than a reference size (M _Q ) of the voice packet, power higher than a reference power is allocated to power of a downlink code channel according to a result of the comparison, M) is greater than a reference size (M _Q ) of the voice packet, allocating a power lower than the reference power to the power of the downlink code channel; Assigning the remaining power allocated to the voice packet to another packet data service; And transmitting the downlink code channel power to the base station. 9. The method of claim 8, And calculating transmission power gain (?) Based on the channel quality indicator (CQI) information. &Lt; RTI ID = 0.0 &gt; [10] &lt; / RTI &gt; 10. The method of claim 9, Wherein the step of assigning power of the downlink code channel comprises: And allocates a power added with a transmission power gain (?) To a reference power if the amount of transmittable data (M) is smaller than a reference size (M _Q ) of a voice packet. Channel power allocation method. 10. The method of claim 9, Wherein the step of assigning power of the downlink code channel comprises: And allocates power with a reduced transmission power gain (?) To the reference power if the amount of transmittable data (M) is greater than a reference size (M _Q ) of a voice packet. Power allocation method. 10. The method of claim 9, Wherein the step of assigning power of the downlink code channel comprises: And allocates a transmission power gain (DELTA) to the reference power for a HS-PDSCH (High Speed-Physical Downlink Shared Channel) code channel or a reduced power for the HS-PDSCH code channel. Way. 9. The method of claim 8, Wherein the step of assigning power of the downlink code channel comprises: And allocating the remaining transmission power allocated to the voice packet to another packet data service to increase the transmission rate. A method for allocating a downlink code channel for a voice service of a base station providing a voice packet service to a user terminal, Receiving channel quality indicator (CQI) information from the user terminal; Checking the amount of transmittable data (M) based on the channel quality indicator (CQI) information and comparing the amount of transmittable data (M) with a reference size (M _Q ) of a voice packet of the voice packet service; If the amount of transmittable data (M) is smaller than a reference size (M _Q ) of the voice packet, power higher than a reference power is allocated to power of a downlink code channel according to a result of the comparison, M) is greater than a reference size (M _Q ) of a voice packet, allocating a power lower than a reference power to power of a downlink code channel; Assigning the remaining power allocated to the voice packet to another packet data service; And a downlink code channel power allocation method for a voice service of a base station including the base station and the base station.

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