KR101368647B1 - System and method for uplink retransmission of voice packets in high-speed wireless communication networks - Google Patents

Abstract

According to the present invention, when a voice packet is transmitted in an uplink using an HSUPA system, a retransmission packet and a new packet are successively transmitted when the voice packet is retransmitted, thereby minimizing the change in the uplink transmission power, thereby increasing the success rate of the voice packet and uplink. The present invention relates to a method and a system for retransmitting an uplink voice packet in a high-speed wireless communication network capable of increasing a voice service capacity.

A user terminal according to the present invention, the communication unit for communicating with the base station; A communication setting unit for setting an uplink communication method based on the allocation information transmitted from the base station; A data transmission unit for transmitting a data packet using a communication scheme set through the communication setting unit; And a control unit for controlling to continuously transmit the next voice packet following the retransmitted voice packet when the voice packet is retransmitted using the set communication method. The control unit sets a retransmission period of the voice packet one unit (TTI) smaller than the generation period of the voice packet.

According to the present invention, it is possible to increase the transmission success rate of the uplink packet by minimizing a sudden change in the transmission power and to increase the uplink voice capacity.

Uplink, voice packet, HSUPA, terminal, base station, retransmission, TTI, period

Description

System and method for uplink retransmission of voice packets in high-speed wireless communication networks

The present invention relates to a method and a system for retransmitting a voice packet in an uplink of a high-speed uplink packet access (HSUPA) network, and more particularly, when retransmitting a voice packet when transmitting a voice packet in an uplink using an HSUPA system. A method of retransmitting an uplink voice packet in a high-speed wireless communication network in which a retransmission packet and a new packet are continuously transmitted to minimize the change in the uplink transmission power, thereby increasing the success rate of the voice packet and increasing the capacity of the uplink voice service. And to the system.

HSUPA is shortened High-Speed stands for Uplink Packet Access, 3 generation mobile enhanced transmission speed of the communications uplink to a mobile communication technology standardized by the 3GPP (3 ^rd Generation Partnership Project), which is responsible for the standardization of systems and transmission delay time Up to 5.76Mbps. HSUPA standardization began with a study item called “uplink enhancements for dedicated transport channels” in September 2002, when HSDPA (high speed downlink packet access) standard was being standardized and standardized by manufacturers such as Motorola, Nokia, and Ericsson. .

HSUPA coexists with existing WCDMA because it uses basic functions such as cell selection, synchronization, random access, and mobility control procedures used in the existing R99 wideband code division multiple access (WCDMA). Channels newly introduced in HSUPA add “E-” to distinguish them from the channels used in existing WCDMA and HSDPA. For reference, a terminal supporting HSUPA for high-speed bidirectional data transmission is always used with HSDPA. Key features of FDD HSUPA provide up to 5.76Mbps in uplink, improve the capacity and throughput of packet data, reduce network delay due to uplink transmission, and combine with HSDPA in both directions The transmission of packet data can be optimized.

The HSUPA has a transmission time interval (TTI), which is a basic transmission unit, and may selectively provide 2 ms and 10 ms for each terminal. At this time, 10ms TTI must be supported essentially, and 2ms TTI can be used to increase the transmission speed. The 10ms frame used in WCDMA consists of 15 time slots. The 10ms TTI has the same length as one frame, and the 2ms TTI consists of three time slots.

1 shows physical channels added to HSUPA and information included in each physical channel. In FIG. 1, user data between the base station 110 and the user terminal 120 is mapped to an enhanced dedicated physical data channel (E-DPDCH). The enhanced dedicated physical control channel (E-DPCCH) includes control information to help the demodulation process while being transmitted simultaneously with the E-DPDCH. Upon receiving the E-DPDCH, the base station 110 informs whether the data has been successfully received through an enhanced HARQ acknowledgment indicator channel (E-HICH) (ACK or NACK).

For uplink transmission using HSUPA, a dedicated physical control channel (DPCCH), an E-DPCCH, and an E-DPDCH are used simultaneously. The DPCCH is not a channel newly added to the HSUPA, but serves as a reference for determining transmission power of other uplink channels.

The transmission of the DPCCH is very important to maintain the continuous link quality for the uplink, but in the case of a lot of terminals transmitting at a low speed, the overhead due to the transmission of the DPCCH may operate as interference to other terminals. Accordingly, in order to solve this problem, 3GPP has introduced a discontinuous transmission (DTX) scheme that transmits the DPCCH periodically instead of continuously. In addition, in order to prevent the difficulty in maintaining uplink quality due to the intermittent transmission of the DPCCH, two slots of preamble and one postamble are always transmitted in front of the DPCCH. For reference, the preamble and the postamble are configured in the same form as the DPCCH.

2 is a diagram for explaining a DTX operation for a DPCCH. In FIG. 2, when uplink data is transmitted through the E-DPDCH, the DPCCH needs to be transmitted together. However, if the E-DPDCH is not transmitted, the DPCCH is transmitted at regular intervals. Only DPCCH is transmitted per DTX_cycle from the last E-DPDCH transmission.

On the other hand, a terminal supporting HSUPA may transmit other data when receiving an ACK after transmitting data, but should retransmit the packet when receiving the NACK. In HSUPA, this retransmission process is very fast. In case of having a TTI of 10ms, a retransmission is attempted at the fourth TTI after the first transmission. In the case of having a TTI of 2ms, the retransmission is attempted at the 8th TTI after the first transmission.

3 is a diagram illustrating an example of transmitting a packet in uplink using an HSUPA technology. In FIG. 3, when the HSUPA technique with TTI = 2ms is used, if an error occurs, retransmission is performed in the eighth slot after the first transmission. In FIG. 3, a packet transmitted in TTI No. 0 receives NACK twice in succession and is retransmitted in TTI Nos. 8 and 6 in order.

In the conventional HSUPA operation, when the low-speed data service is supported, DTX of DPCCH is necessary to reduce uplink interference because the data is sometimes transmitted using the E-DPDCH, but DTX sometimes transmits the DPCCH. Difficult to maintain In addition, since the transmission power of the E-DPDCH is much higher than that of the DPCCH, the interference and signal quality in the TTI which transmits only the DPCCH and the TTI which simultaneously transmits the DPCCH / E-DPCCH / E-DPDCH may be very different. have. Therefore, there may be a big difference between the optimal DPCCH transmission strength for DPCCH only and the optimal DPCCH transmission strength for DPCCH / E-DPCCH / E-DPDCH transmission. Therefore, as shown in FIG. 3, when the transmission channel combination of the terminal is changed, the optimal intensity of the DPCCH must also be changed, but it is very difficult to find and transmit the optimal intensity for a short period.

An object of the present invention for solving the above problems is to minimize the change in uplink transmission power by continuously transmitting a retransmission packet and a new packet in succession when the voice packet is retransmitted when the voice packet is transmitted uplink using the HSUPA system. The present invention provides an uplink voice packet retransmission system, a user terminal, and an uplink voice packet retransmission method in a high-speed wireless communication network capable of increasing the success rate of voice packets and increasing uplink voice service capacity.

The uplink voice packet retransmission system according to the present invention for achieving the above object, allocates resources for uplink transmission to the user terminal during the voice service, at a predetermined time interval from the user terminal until the end of the voice service A base station for receiving a voice packet; And a user terminal that transmits a voice packet in uplink using resources allocated from the base station and continuously transmits a next voice packet following a voice packet retransmitted upon retransmission of the voice packet.

On the other hand, the user terminal according to the present invention for achieving the above object, a communication unit for communicating with the base station; A communication setting unit for setting an uplink communication method based on the allocation information transmitted from the base station; A data transmission unit for transmitting a data packet using a communication scheme set through the communication setting unit; And a control unit for controlling to continuously transmit the next voice packet following the retransmitted voice packet when the voice packet is retransmitted using the set communication method.

The control unit may generate the voice packet periodically at a first time interval, and the retransmission of the voice packet may be transmitted after a second time after a failure of the voice packet transmission, and the second time may be transmitted. Set less than 1 hour.

The control unit discards the voice packet if the voice packet is not transmitted for a predetermined time or more.

Meanwhile, an uplink voice packet retransmission method of a user terminal according to the present invention for achieving the above object is an uplink voice packet retransmission method of a user terminal transmitting a voice packet to the base station using resources allocated from a base station. (a) the user terminal transmitting a voice packet to the base station; (b) retransmitting the voice packet when the user terminal does not receive a response of the voice packet transmitted from the base station; And (c) continuously transmitting the next voice packet following the retransmitted voice packet.

In addition, the voice packet is periodically generated and is generated at a first time interval, and the retransmission of the voice packet is transmitted after a second time after the failure of the voice packet transmission, but the second time is smaller than the first time. Set it.

In the step (b), if the voice packet is not transmitted for a predetermined time or more, the voice packet is discarded.

On the other hand, the medium for recording the uplink voice packet retransmission method of the user terminal according to the present invention for achieving the above object, the program comprising: (a) transmitting a voice packet to the base station by the user terminal; (b) retransmitting the voice packet when the user terminal does not receive a response of the voice packet transmitted from the base station; And (c) continuously transmitting the next voice packet subsequent to the retransmitted voice packet to a computer-readable medium as a program.

According to the present invention, it is possible to increase the transmission success rate of the uplink packet by minimizing a sudden change in the transmission power and to increase the uplink voice capacity.

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.

If the channel combinations transmitted by the user terminal are different, the optimal DPCCH transmission strength may vary depending on the TTI. In general, since it is very difficult to quickly find the optimal DPCCH strength under rapidly changing TTI load conditions, uplink transmission quality may be improved when the channel combination pattern according to TTI is set to not change as much as possible.

The adaptive multi-rate (AMR) voice codec used in a general mobile communication system can continuously generate voice packets, but can vary at various transmission speeds in order to increase radio resource efficiency. In particular, the AMR codec distinguishes an ON section in which a voice packet is generated and an OFF section in which a voice packet is not generated, thereby generating more packets in the ON section. Normally, the length of the ON interval is about 1 second on average, and voice packets are generated 244 bits at 20 ms intervals. The average length of the OFF section is about 1 second, and a 39-bit silence insertion descriptor (SID) packet including background noise is generated every 160 ms without outputting voice information. Since the transmission speed of voice data is only 12.2kbps in the ON section, it is regarded as a low speed service in the third generation mobile communication system. When using the HSUPA technology with TTI = 2ms, voice packets are generated every 20 ms, so if no error occurs, they are transmitted once every 10 TTI through the E-DPDCH.

4 is a view schematically showing a functional block of a user terminal according to an embodiment of the present invention.

Referring to FIG. 4, the user terminal 120 according to the present invention includes a communication unit 410, a communication setting unit 420, a data transmission unit 430, and a control unit 440.

The communication unit 410 communicates with the base station 110.

The communication setting unit 420 sets an uplink communication method based on the allocation information transmitted from the base station 110.

The data transmitter 430 transmits the data packet using a communication method set through the communication setting unit 420.

The controller 440 controls to continuously transmit the next voice packet following the retransmitted voice packet when the voice packet is retransmitted using the set communication method.

In addition, the control unit 440 sets the retransmission period of the voice packet one unit (TTI) smaller than the generation period of the voice packet.

The control unit 440 discards the voice packet if the voice packet is not transmitted for a predetermined time or more.

5 is a flowchart illustrating an uplink voice packet retransmission method of a user terminal according to an embodiment of the present invention.

Referring to FIG. 5, first, the user terminal 120 transmits a voice packet to the base station 110 (S510).

In the embodiment of the present invention, it is assumed that the transmission period M of the voice packet is 10 TTI. First, the user terminal 120 transmits the voice packet generated in the AMR codec to the base station 110 using the E-DPDCH.

Upon receiving the ACK from the base station 110 (S520-No), the user terminal 120 transmits the voice packet generated at 20 ms intervals.

However, if the NACK is received from the base station 110 in response to the transmission failure with respect to the transmitted voice packet (S520-Yes), the user terminal 120 prepares to retransmit the voice packet (S530).

Subsequently, the user terminal 120 determines whether it is within the allowable delay time, and when it is within the allowable delay time (S540-Yes), transmits the retransmission packet at a time point that is 1 unit (TTI) smaller than the time at which the next voice packet is transmitted ( S550).

Here, M is a transmission period of the voice packet, and the user terminal 120 sets the retransmission period of the voice packet one unit (TTI) smaller than the generation period of the voice packet.

That is, the retransmission packet can be retransmitted as long as it is within the allowable delay time range. The retransmission packet is retransmitted after the (M-1) TTI at the previously transmitted TTI position so that the E-DPDCH transmission can be continuously performed. This process continues until an ACK is received or abandoned transmission for a retransmission packet.

In this case, if the user terminal 120 does not receive a response from the base station 110 after continuously transmitting the voice packet (S570-No), the user terminal 120 proceeds to step S530 to prepare for retransmission of the voice packet and receives the response. If (S570-Yes) the voice service is terminated (S580-Yes), the operation is terminated, otherwise (S580-No) proceeds to step S510 to transmit the voice packet to the base station (110).

On the other hand, if the allowable delay time is out (S540-No), the user terminal 120 discards the voice packet (S590).

6 is a diagram illustrating an example of a retransmission pattern according to an embodiment of the present invention.

Referring to FIG. 6, when a NACK is received for a packet transmitted in TTI # 0, the existing method should retransmit in TTI # 8. However, according to the present invention, a new voice packet is transmitted next. For this purpose, the retransmission packet may be slightly longer than the conventional method. However, in two neighboring TTIs, since the combination of DPCCH / E-DPCCH / E-DPDCH is the same, the optimal transmit power of the DPCCH will be very similar to that of the previous slot compared to the case where only the DPCCH is transmitted. If the optimal transmit powers are similar, power control can operate efficiently, which can increase the packet transmission success rate.

In addition, when a plurality of voice packets are retransmitted, discontinuous transmission may occur between retransmitted packets or between a retransmitted packet and a new packet according to the success of HARQ, and thus the retransmission position may be determined to be transmitted as continuously as possible. .

When the voice packet is transmitted in the uplink using the HSUPA system, the retransmission packet and the new packet are successively transmitted when the voice packet is retransmitted, thereby minimizing the change in the uplink transmission power, thereby increasing the success rate of the voice packet and the capacity of the uplink voice service. The uplink voice packet retransmission system, the user terminal, and the uplink voice packet retransmission method can be realized in a high-speed wireless communication network.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. 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 a user terminal for transmitting a voice packet to the base station in uplink.

1 is a diagram illustrating physical channels added to HSUPA and information included in each physical channel.

2 is a diagram for explaining a DTX operation for a DPCCH.

3 is a diagram illustrating an example of transmitting a packet in uplink using an HSUPA technology.

4 is a view schematically showing a functional block of a user terminal according to an embodiment of the present invention.

5 is a flowchart illustrating an uplink voice packet retransmission method of a user terminal according to an embodiment of the present invention.

6 is a diagram illustrating an example of a retransmission pattern according to an embodiment of the present invention.

Description of the Related Art

110: base station 120: user terminal

410: communication unit 420: resource setting unit

430: data transmission unit 440: control unit

Claims (8)

A base station for allocating resources for uplink transmission to a user terminal during voice packet service and receiving voice packets from the user terminal at predetermined time intervals until the end of the voice packet service; And A user terminal for continuously transmitting the next voice packet following the retransmitted voice packet when retransmitting the voice packet using the resource allocated from the base station; Uplink voice packet retransmission system comprising a. A communication unit for communicating with a base station; A communication setting unit for setting an uplink communication method based on the allocation information transmitted from the base station; A data transmitter for transmitting a data packet using a resource set through the communication setting unit; And A control unit which controls to continuously transmit the next voice packet following the retransmitted voice packet when the voice packet is retransmitted using the set resource; Lt; / RTI > The method of claim 2, The control unit periodically generates the voice packet at a first time interval, and retransmits the voice packet after the second time after the transmission failure of the voice packet, but transmits the second time to the first time. A user terminal, characterized in that smaller setting. The method of claim 2, The control unit discards the voice packet if the voice packet is not transmitted for a predetermined time or more. A method for retransmitting an uplink voice packet of a user terminal for transmitting a voice packet to the base station using resources allocated from a base station, (a) the user terminal transmitting a voice packet to the base station; (b) retransmitting the voice packet when the user terminal does not receive a response of the voice packet transmitted from the base station; And (c) continuously transmitting a next voice packet following the retransmitted voice packet; Uplink voice packet retransmission method of a user terminal comprising a. 6. The method of claim 5, The voice packet is periodically generated and is generated at a first time interval, and the retransmission of the voice packet is transmitted after a second time after the failure of the voice packet transmission, but the second time is set smaller than the first time. Uplink voice packet retransmission method of the user terminal, characterized in that. 6. The method of claim 5, If the voice packet is not transmitted for a predetermined time in step (b), the voice packet retransmission method of the user terminal, characterized in that for discarding. A medium recording a method of retransmitting an uplink voice packet of a user terminal for transmitting a voice packet to the base station by using a resource allocated from a base station, (a) the user terminal transmitting a voice packet to the base station; (b) retransmitting the voice packet when the user terminal does not receive a response of the voice packet transmitted from the base station; And (c) continuously transmitting a next voice packet following the retransmitted voice packet; A computer-readable medium in which a method of retransmitting an uplink voice packet of a user terminal including a program is recorded.

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