KR100672403B1 - Method for transmitting Reverse Quality Indicator Echo Channel - Google Patents

Abstract

The present invention relates to a mobile communication system, and more particularly, to a reverse quality indicator and an echo channel (R-QIECH) transmission method used in 1XTREME of cdma2000. Determining whether the mobile station has requested retransmission of the packet data received by the serving base station when switching to another base station according to the selection; and when the retransmission request is made as a result of the determination, the mobile station transmits to the switched base station. Transmitting Walsh code information used for the packet data, modulation and coding level information, service reference information, and sequence information of the received packet data unit, and when the retransmission request is not made as a result of the determination Whether the mobile station has multipath energy at the switched base station. And transmitting the information, the pilot signal power measurement information necessary for determining the modulation and coding level, and the sequence information of the received packet data unit.

R-QIECH, MCS Level

Description

Method for transmitting Reverse Quality Indicator Echo Channel

1 is a view showing a field included in the R-QIECH according to the prior art

2 is a flowchart illustrating a transmission process of an R-QIECH according to the present invention.

3 illustrates a field included in an R-QIECH according to the present invention.

The present invention relates to a mobile communication system, and more particularly, to a reverse quality indicator and an echo channel (R-QIECH) transmission method used in 1XTREME of cdma2000.

As is known, 1x DO (Data Only) is a mobile communication technology that increases the data transfer rate to more than 2Mbps only in cdma2000-1XTREME, which is called 2.5G mobile communication, and is representative of HDR (High Data Rate) developed by Qualcomm. On the contrary, 1x-EV DV is a service method that supports voice while realizing a data rate of 2 to 3Mbps even in a mobile section.

That is, 1x-EV DV is a general term for standardization to support not only existing voice service but also high speed packet data service based on the 1x technology of the existing synchronous cdma2000 RTT.

Unlike the existing 1x RTT technology on the air interface, the 1x-EV DV adopts the adaptive modulation and coding (abbreviated as AMC) technique and the HARQ scheme in the forward direction.

This AMC technique is used for a forward shared channel for transmitting high speed packets, and is a method of selecting a modulation coding scheme (hereinafter, referred to as MCS) based on channel conditions.

In other words, if the channel environment is good, high-level modulation techniques (8PSK, 16QAM, 64QAM) and high coding rates are used to transmit high-speed data, and if the channel environment is bad, low-speed modulation is used to transmit low-speed data. Technique (QPSK), a technique that applies a low coding rate.

The method for determining the MCS level includes measuring the power of a pilot signal transmitted from a base station and informing the base station (Bast Transceiver System) of the measured information. Decide

In this case, the pilot signal power measurement information is transmitted to the base station through a reverse quality indicator and an echo channel (hereinafter, referred to as R-QIECH).

In the link adaptation scheme, the AMC scheme determines the approximate data throughput, and the HARQ scheme determines the more suitable data throughput.

In this link adaptation scheme, in order to apply the HARQ protocol to high-speed packet transmission, the HARQ protocol must proceed rapidly. Therefore, the 1xTREME system applies the HARQ protocol supported by the physical layer.

The reason for applying the HARQ protocol in the physical layer is that the conventional HARQ protocol is controlled in the link access control (Link Access Control) is controlled in the medium access control (Medium Access Control (hereinafter referred to as MAC)) layer system delay This can be minimized.

That is, the conventional HARQ protocol is controlled by each base station to be controlled by the base station controller (Base Station Controller), the HARQ protocol application is faster to facilitate high-speed packet data transmission.

However, there are a few things to note in order for the base station to control the HARQ protocol.

In the 1xTREME system, fast cell site selection is a technique for selecting a base station having the best channel condition among the base stations included in the active set instead of the soft handoff to prevent additional interference of the reverse link. Selection (hereinafter abbreviated as FCSS) technique is applied.

Therefore, when switching occurs from a base station being serviced to an arbitrary terminal to another base station selected by FCSS, the terminal should inform the switched base station of the progress information of the HARQ protocol that was previously applied to the base station being served.

At this time, the progress information of the HARQ protocol is also transmitted from an arbitrary terminal to the corresponding base station through the R-QIECH, similarly to the pilot signal measurement information.

The R-QIECH is an MD indicating whether there is multipath energy, a PILOT_STRENGTH indicating pilot measurement information required for the base station to determine the MCS level, and a Walsh used for the FSHCH received by the mobile station, as shown in FIG. PYLD4 including code information, MCSL including MCS level information applied to FSHCH received by the mobile station, SR_ID including service reference information, and SEQ_UN field including the sequence number of the FSHCH packet data unit.

The MD and PILOT_STRENGTH fields are information necessary for determining the MCS level at the base station, and the PYLD4, MCSL, SR_ID, and SEQ_UN fields are necessary for the switched base station to apply the HARQ protocol when switching to another base station occurs by FCSS. Information.

This is because the HARQ protocol of the normal physical layer can be executed only by informing the switched base station of the HARQ protocol information that has been performed in the base station before switching.

In this case, the R-QIECH has two transmission speeds (half rate) for MCS level determination (send pilot signal measurement information from the mobile station to the base station being serviced) and HARQ protocol information transmission (transmission from the mobile station to the switched base station). rate, full rate).

For example, when the base station is not switched, the R-QIECH is transmitted at half rate, and only the MD and PILOT_STRENGTH fields are transmitted.                         

However, when a base station serving any terminal is switched to another base station by FCSS, the R-QIECH from the mobile station is transmitted to the base station switched at full rate, and transmits all fields included in the R-QIECH. This also causes unnecessary fields to be transmitted, increasing the overhead of this R-QIECH.

Accordingly, an object of the present invention has been made in view of the above-mentioned problems of the prior art, and the reverse quality indicator which can reduce the overhead of the reverse quality indicator and echo channel (R-QIECH) that may be caused by FCSS, and It is to provide a transmission method of an echo channel (R-QIECH).

According to an aspect of the present invention for achieving the above object, a packet received by the mobile station to the base station that the mobile station, when the base station being serviced to any terminal is switched to another base station according to the high-speed cell site selection Determining whether a request for retransmission of data has been requested; and when the retransmission request is made as a result of the determination, the mobile station transmits the Walsh code information used for the packet data to the switched base station, modulation and coding level information, service reference information, and the like. Transmitting the sequence information of the received packet data unit; and, if the retransmission request is not made as a result of the determination, information on whether the mobile station has multipath energy in the switched base station, and modulation and coding level Pilot signal power measurement information necessary to determine the transmission and the transmission It is achieved, including the step of transmitting the information sequence of packet data units.                         

Preferably, the switched base station retransmits the packet data to the mobile station using the Walsh code information, the modulation and coding level information, the service reference information, and the sequence information of the received packet data unit.

Accordingly, the mobile station combines and decodes the packet data and the retransmitted packet data of the data.

The switched base station determines the modulation and coding level of the newly transmitted packet data using information on whether there is multipath energy, pilot signal power measurement information, and sequence information of the received packet data unit.

Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

According to the present invention, when a base station serving an arbitrary terminal is switched to a new base station by fast cell site selection (hereinafter abbreviated as FCSS), the mobile station is connected to the switched base station via R-QIECH. We propose an algorithm that reduces the overhead of R-QIECH by effectively selecting the transmitted field.

As described above, in 1XTREME, the mobile station informs the base station of the pilot signal power measurement information of the forward link through the R-QIECH so that the base station serving the mobile station determines the MCS level.

The base station in service transmits data to the mobile station according to the determined MCS level.

However, when switching to a new base station by FCSS, the mobile station likewise informs the switched base station via R-QIECH of the progress information of the HARQ protocol with the base station before switching.

At this time, the fields included in this R-QIECH differ depending on whether the channel is transmitted to the base station being serviced by the mobile station before the R-QIEHC is switched or whether the channel is transmitted to the base station switched by FCSS.

When switching to a new base station by FCSS, if the mobile station requests retransmission of a packet according to the HARQ scheme before being switched, the switched base station is the same MCS as the packet transmitted from the base station before switching. Since the packet must be retransmitted to the mobile station with the level, the Walsh code, and the same SR_ID, only the PYLD4, MCSL, SR_ID, and SEQ_UN fields need to be transmitted from the mobile station through the R-QIECH.

However, when switching to a new base station by FCSS, if the mobile station did not request retransmission of the packet to the serving base station before switching, the newly switched base station may transmit the packet to the mobile station at the new MCS level. The additional field SEQ_UN is needed because it needs to know the MD, PILOT_STRENGTH field needed to determine the MCS level, and how many times the base station has transmitted the packet to the mobile station before switching.

Therefore, in the present invention, as shown in FIG. 2, first, it is determined whether switching has occurred to another base station by FCSS while receiving a packet from a base station in which the mobile station is serving.

If switching occurs while receiving the packet, the mobile station determines whether or not the base station has requested retransmission of the received packet before switching.

Therefore, if a retransmission request occurs, the mobile station transmits an R-QIECH including the PYLD4, MCSL, SR_ID, and SEQ_UN fields to the switched base station.

This is because the newly switched base station must transmit the same MCS, Walsh code, and packet data required for retransmission to the same SR_ID as the base station before switching to the corresponding mobile station (S12).

The mobile station combines the packet data initially transmitted from the base station before the switching and the packet data retransmitted from the switched base station to decode the packet data.

However, if no retransmission request has occurred, the mobile station sends an R-QIECH including MD, PILOT_STRENGTH, SEQ_UN fields to the switched base station.

The newly switched base station determines a new MCS level using the PILOT_STRENGTH field.

In addition, the newly switched base station uses the SEQ_UN field to determine how many packets have been transmitted from the base station before switching to the mobile station, and transmits the subsequent packet to the mobile station at the newly determined MCS level. (S13)

However, if switching to another base station has not occurred by FCSS, the mobile station may include an R-QIECH including MD and PILOT_STRENGTH fields so that the base station serving this mobile station can change the MCS level appropriately for the changing channel environment. Transmit to the corresponding base station (S14).

In summary, the present invention determines whether or not switching occurs according to the FCSS application, or if the mobile station requests retransmission of a packet transmitted from the corresponding base station before switching if the switching occurs. As shown in FIG. 3, the R-QIECH is transmitted to the base station before switching or the base station after switching in three modes.

3, before switching occurs, the mobile station transmits an R-QIECH having mode 1 to the base station. In this case, the R-QIECH includes MD and PILOT_STRENGTH fields.

When switching is generated by the FCSS and the mobile station requests retransmission of the received packet to the serving base station before the switching occurs, the mobile station transmits an R-QIECH having mode 2 to the newly switched base station. In this case, R-QIECH transmits PYLD4, MCSL, SR_ID and SEQ_UN.

If switching is generated by the FCSS, and the mobile station does not require retransmission of the received packet to the serving base station before the switching occurs, the mobile station sends an R-QIECH having mode 3 to the newly switched base station.

In this case, the R-QIECH includes MD, PILOT_STRENGTH, and SEQ_UN fields.

In FIG. 3, MD consists of 1 bit, PILOT_STRENGTH is 6 bits, PYLD4 is 4 bits, MCSL is 3 bits, SR_ID is 3 bits, and SEQ_UN is 12 bits.

By applying the three modes in this way, the overhead is reduced by transmitting only the necessary fields.

As described in the above description, the present invention transmits the R-QIECH in each transmission mode in consideration of whether switching by the FCSS and retransmission is performed based on the switching time so that the existing unnecessary field is not transmitted. This can reduce overhead.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

Claims (4)

When the base station being serviced to any terminal is switched to another base station according to the fast cell site selection, Determining whether the mobile station has requested retransmission of the received packet data to the base station being served; When the retransmission request is made as a result of the determination, the mobile station transmits Walsh code information, modulation and coding level information, service reference information, and sequence information of the received packet data unit to the switched base station. Transmitting, As a result of the determination, when the retransmission request is not made, information on whether the mobile station has multipath energy in the switched base station, pilot signal power measurement information necessary to determine a modulation and coding level, and the received packet And transmitting the sequence information of the data unit, characterized in that it comprises the step of transmitting the reverse quality indicator and the echo channel (R-QIECH) 4. The method of claim 1, wherein the switched base station retransmits the packet data to the mobile station using the Walsh code information, modulation and coding level information, service reference information, and sequence information of the received packet data unit. Characterized by the reverse quality indicator and the transmission method of the echo channel (R-QIECH) 3. The method of claim 2, wherein the mobile station combines and decodes the packet data and the retransmitted packet data of the data. The method of claim 1, wherein the switched base station determines the modulation and coding level of the newly transmitted packet data using information on whether there is multipath energy, pilot signal power measurement information, and sequence information of the received packet data unit. A reverse quality indicator and a transmission method of an echo channel (R-QIECH)

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