CN100499654C - Channel quality monitoring method in high speed downward block switch-in system - Google Patents

Abstract

The invention relates to the third-generation mobile communication technology, and discloses a channel quality monitoring method in a high-speed downlink packet access system, which makes the monitoring of the downlink channel quality more accurate. In the present invention, when the length of the MAC-hs PDU does not match the length specified in the protocol, the stuffing bits are filled in according to the preset mode; after receiving, the UE compares the ratio of the erroneous bits in the stuffing bits to the total stuffing bits , after obtaining the BER, convert it into other channel quality indicators such as CQI according to the need. If the length of the PDU matches the length specified by the protocol, based on the matched length, a minimum length specified by the protocol can be indexed upward.

Description

Channel quality monitoring method in high-speed downlink packet access system

technical field

The invention relates to the third-generation mobile communication technology, in particular to the high-speed downlink packet access technology.

Background technique

The 3rd Generation Partnership Project (3rd Generation Partnership Project, referred to as "3GPP") is the leading technical specification organization for the third generation of mobile communications (The Third Generation, referred to as "3G"). The organization was established at the end of 1998 to research, formulate and promote the 3G standard based on the core network of the evolved Global System for mobile Communication ("GSM"), that is, Wideband Code Division Multiple Access (WCDMA). , "WCDMA" for short), Time Division Synchronous Code Division Multiple Access ("TD-SCDMA" for short), Enhanced Data Rates for GSM Evolution ("EDGE" for short), etc. .

High Speed Downlink Packet Access (HSDPA for short) is a modulation and demodulation algorithm proposed by 3GPP in the R5 protocol in order to meet the asymmetrical requirements of uplink and downlink data services. In the case of a WCDMA network structure, the downlink data service rate is increased to 10Mbps. This technology is an important technology for improving the downlink capacity and data service rate in the later stage of WCDMA network construction.

In the implementation of the HSDPA algorithm, the user equipment (User Equipment, referred to as "UE") feeds back the downlink high-speed physical downlink shared channel ( High SpeedPhysical Downlink Shared Channel, referred to as "HS-PDSCH") channel channel quality indicator (Channel Quality Indicator, referred to as "CQI"), through the analysis of CQI reported by all UEs, the base station node (Node Base Station, referred to as "NodeB") The channel quality of each UE can be obtained, so as to determine the allocation of shared resources in each UE. The downlink channel quality CQI is obtained indirectly by the UE by measuring the quality of the downlink PCPICH pilot channel.

For the definition of CQI in the protocol, please refer to "3GPP TS 25.214 V5.6.0, Sep.2003".

During the unrestricted observation time, the UE reports the highest CQI value, which meets the following conditions:

The UE can receive a single HS-DSCH subframe formed with the transport block size, HS-PDSCH code number, and modulation scheme corresponding to the reported CQI value or a lower CQI value within the reference time of 3 slots. The reference time ends at One slot before the first slot of the subframe where the CQI value is transmitted; and the transmission block error probability does not exceed 0.1.

In order to obtain the CQI value, the UE assumes that the total received power of the HS-PDSCH is P _HSPDSCH =P _CPICH +Γ+ΔdB, and the total received power is evenly distributed on all HS-PDSCH codes that report the CQI value, where the measurement power offset Γ is determined by the upper layer Given, the reference power adjustment Δ depends on the UE classification.

The CQI value acquisition is based on the Gaussian channel propagation environment. In a specific CQI mapping modulation mode, the UE can obtain the curve of the single transmission block error rate BLER according to the received HS-PDSCH signal-to-noise ratio, and take BLER=0.1 to correspond The HS-PDSCH signal-to-noise ratio SNR and CQI value can be obtained, and the mapping curve of the received HS-PDSCH signal-to-noise ratio and CQI value can be obtained, and then the CQI mapping table can be generated. The CQI acquisition process is shown in Figure 1 and Figure 2 .

It can be seen that the above method of obtaining CQI is only applied under the condition of an Additive White Gaussian Noise (AWGN for short) channel. If the channel environment is not AWGN, then the CQI will be related to the actual block error rate (Block Error Rate, or "BLER") equal to 0.1 is biased against the target.

The data before channel coding transmitted on the downlink HS-PDSCH channel is composed of MAC-hs PDU (High Speed Media Access Control Protocol Data Unit) data format, as shown in Figure 3.

Among them, the format defined by the protocol mainly consists of one MAC header and multiple MAC-hs SDUs. The MAC header is variable in length and consists of VF, queue ID, TSN, SID, N, F, etc. Among them, VF is fixedly set to 0, which is used for future expansion and occupies 1 bit; the queue ID is the queue ID of the queue where the data to be sent is located, occupying 3 bits; TSN is the sending sequence number of the queue, occupying 6 bits; SID corresponds to the Sizeindex of the MAC-d PDU, Occupies 3 bits; N indicates the number of MAC-d PDUs, accounting for 7 bits; F is 0, indicating that a SID field follows; F is 1, indicating that following a MAC-d PDU, accounting for 1 bit.

Among them, one MAC-hs SDU is one MAC-d PDU, which is the initial data packet delivered by RNC to MAC-hs. Since the protocol has stipulated 254 optional lengths of MAC-hs PDU, see "3GPP TS 25.321 V5.7.0, Dec.2003"; when the data length does not match the specified length, padding bits (padding bit) matches the data length with the specified length, see the Padding option in Figure 3. In the protocol, these padding bits do not specify the padding value and have no purpose.

In practical applications, the above solution has the problem that the monitoring of downlink channel quality is not accurate enough.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a method for monitoring channel quality in a high-speed downlink packet access system, so that the monitoring of downlink channel quality is more accurate.

In order to achieve the above object, the present invention provides a method for monitoring channel quality in a high-speed downlink packet access system, comprising the following steps:

A determines whether the length of the high-speed media access control protocol data unit matches the length specified in the protocol. If the length of the high-speed media access control protocol data unit does not match the length specified in the protocol, the network side fills in the high-speed media access control protocol in a preset mode The padding bits in the data unit make the data length match the specified length, and send the protocol data unit with the specified length in the protocol;

When the B user equipment receives the protocol data unit, it compares the content of the filling bits therein with the preset mode bit by bit, divides the number of erroneous bits by the total number of filling bits, and obtains the bit error rate;

C calculates the channel quality indication according to the bit error rate.

Wherein, said step A also includes the following sub-steps:

If the length of the high-speed media access control protocol data unit matches the length specified in the protocol, then on the basis of the matching length, index upward to a minimum length specified in the protocol, and the network side fills in the high-speed media access control protocol data unit in a preset mode The padding bits in , make the data length match the indexed length, and use the indexed length to send the protocol data unit.

In addition, in the method, the preset mode may be all 0s.

Furthermore, in the method, the preset mode may be all 1s.

Furthermore, in the method, the preset pattern may be a predefined fixed sequence.

In addition, in the method, the preset mode can be calculated according to a predefined algorithm.

By comparison, it can be found that the main difference between the technical solution of the present invention and the prior art is that when the length of the MAC-hs PDU does not match the length specified in the protocol, fill in the padding bits according to the preset mode; Comparing the ratio of the erroneous bits in the filling bits to the total filling bits, the BER (bit error rate) is obtained, and then converted into other channel quality indicators such as CQI as required.

If the length of the PDU matches the length specified by the protocol, based on the matched length, a minimum length specified by the protocol can be indexed upward.

This difference in the technical solution brings obvious beneficial effects, that is, the quality of the downlink channel can be monitored more accurately because of the additional BER information.

Because the original useless MAC-hs PDU Padding bit is used, it will not increase the burden of transmission.

Description of drawings

Figure 1 is CQI1 15, HS-PDSCH signal-to-noise ratio (Signal Noise Ratio, referred to as "SNR") and BLER curve under Additive White Gaussian Noise ("AWGN" for short);

Figure 2 is CQI16-30, HS-PDSCH SNR and BLER curves under AWGN;

Figure 3 is the MAC-hs PDU format defined by the protocol;

Fig. 4 is a schematic flow chart of a channel quality monitoring method in HSDPA according to a preferred embodiment of the present invention;

Fig. 5 is a schematic flowchart of a method for monitoring channel quality in HSDPA according to another preferred embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The core of the present invention is to use the MAC-hs PDU filling bit information to monitor the quality BER of the downlink channel, thereby more accurately monitoring the quality BER of the downlink channel.

Fig. 4 shows a method for monitoring channel quality in HSDPA according to an embodiment of the present invention. As shown in the figure, first in step 600: judge whether the length of the MAC-hs PDU matches the length specified in the protocol. If they match, go to step 610, if not, go to step 640.

In step 610: on the basis of the matching length, index upward to a minimum protocol-specified length, and leave the length of padding bits for the difference between the two lengths.

Next, in step 620: the network side fills in the padding bits in a preset mode. The protocol stipulates that filling bits are filled at the end of the data to match the data length with the specified length. In this embodiment, the preset mode may be all 0s. In other embodiments according to the present invention, the preset pattern may be all 1s, or may be a predefined fixed sequence. In addition, the preset pattern may also be calculated according to a predefined algorithm.

Thereafter, in step 630: use the indexed length to send the PDU to the UE.

On the other hand, as mentioned above, if it is determined in step 600 that the length of the MAC-hs PDU does not match the length specified in the protocol, then in step 640, the network side fills in the padding bits in a preset mode. The protocol stipulates to fill in padding bits at the end of the data to match the data length with the specified length. Wherein, similar to step 620, the preset pattern can be all 0s, or all 1s, or a predefined fixed sequence, and can also be calculated according to a predefined algorithm.

In step 650: Send the PDU to the UE with the length specified in the protocol.

Thereafter, in step 660, when the UE receives the PDU, it compares the content of the stuffing bits with the preset pattern bit by bit, divides the number of error bits by the total number of stuffing bits, and obtains the BER. Specifically, in step 630 or step 650, the MAC-hs PDU data is sent at the base station antenna port after being channel-coded, and the downlink channel scrambled MAC-hs PDU code is received at the UE side through the air transmission of the downlink channel After the data, after the UE performs channel decoding, the MAC-hs PDU data received by the UE side is obtained, and the data of the received MAC-hs PDU data is compared. If the bit is not 0, the bit is recorded as an error ; otherwise, it is recorded as correct. By calculating the proportional relationship between the number of filling bit errors and the total number, the BER of the data can be obtained initially, and the BER of the current HS-PDSCH is also obtained.

At step 670: Calculate the CQI based on the BER. As mentioned above, in order to obtain the CQI value, the UE assumes that the total received power of the HS-PDSCH is P _HSPDSCH = P _CPICH +Γ+ΔdB, and the total received power is evenly distributed on all HS-PDSCH codes that report the CQI value, and the measured power is biased The setting Γ is given by the higher layer, and the reference power adjustment Δ depends on the UE classification.

The CQI value acquisition is based on the Gaussian channel propagation environment. In a specific CQI mapping modulation mode, the UE can obtain the curve of the single transmission block error rate BLER according to the received HS-PDSCH signal-to-noise ratio, and take BLER=0.1 to correspond The HS-PDSCH signal-to-noise ratio SNR and CQI value can be obtained, and the mapping curve of the received HS-PDSCH signal-to-noise ratio and CQI value can be obtained, and then the CQI mapping table can be generated. The CQI acquisition process is shown in Figure 4 and Figure 5 .

Another preferred embodiment of the present invention is described below, as shown in Figure 5, in step 700: judge whether the length of MAC-hs PDU matches with the agreement regulation length, if match, then enter step 710, if do not match, then enter Step 740.

In step 710: normally send the PDU with the length specified in the protocol, and then enter step 760. This step is completely the same as that of the prior art, and relevant details can be found in relevant protocols.

Step 740 and step 750 are the processing when they do not match, which are completely the same as step 640 and step 650 in the previous embodiment, and will not be repeated here. Enter step 760 after step 750 is completed.

Step 760 and step 770 are related processing at the receiving end, which are completely the same as step 660 and step 670 in the previous embodiment, and will not be repeated here.

The difference between this embodiment and the previous embodiment is that the length of the MAC-hs PDU is different from the processing when the length specified in the protocol matches. Padding bits. The advantage of this embodiment is that no additional burden is added to the transmission, and the existing padding bits are fully utilized. The advantage of the previous embodiment is that regardless of whether the length of the PDU matches the length of the protocol, the channel quality can be monitored by filling bits, and the processing is relatively uniform. The disadvantage is that a small amount of transmission burden is increased.

It can be seen that, in the present invention, when the length of the MAC-hs PDU does not match the length specified by the protocol, fill in the stuffing bits according to the preset mode, and send the PDU with the specified length of the protocol. When the length of the MAC-hs PDU matches the length specified by the protocol, based on the matching length, index upward to a minimum length specified by the protocol, then fill in the padding bits in the preset mode, and send the PDU with the indexed length PDUs. After receiving it, the UE compares the ratio of the erroneous bits in the stuffing bits to the total stuffing bits to obtain the BER, which is then converted into other channel quality indicators such as CQI as needed. Because the BER information is added when monitoring the quality of the downlink channel, the data is more accurate, and at the same time, because the original useless MAC-hs PDU filling bits are used, the burden of transmission will not be increased.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, 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 present invention. The spirit and scope of the invention.

Claims (6)

1. a method for monitoring channel quality in a high-speed downlink packet access system, characterized in that, comprising the following steps: A determines whether the length of the high-speed media access control protocol data unit matches the length specified in the protocol. If the length of the high-speed media access control protocol data unit does not match the length specified in the protocol, the network side fills in the high-speed media access control protocol in a preset mode The padding bits in the data unit make the data length match the specified length, and send the protocol data unit with the specified length in the protocol; When the B user equipment receives the protocol data unit, it compares the content of the filling bits therein with the preset mode bit by bit, divides the number of erroneous bits by the total number of filling bits, and obtains the bit error rate; C calculates the channel quality indication according to the bit error rate. 2. the channel quality monitoring method in the high-speed downlink packet access system according to claim 1, is characterized in that, described step A also comprises the following sub-steps: If the length of the high-speed media access control protocol data unit matches the length specified in the protocol, then on the basis of the matching length, index upward to a minimum length specified in the protocol, and the network side fills in the high-speed media access control protocol data unit in a preset mode The padding bits in , make the data length match the indexed length, and use the indexed length to send the protocol data unit. 3. The method for monitoring channel quality in a high-speed downlink packet access system according to claim 1 or 2, wherein the preset mode can be all 0s. 4. The method for monitoring channel quality in a high-speed downlink packet access system according to claim 1 or 2, wherein the preset mode can be all 1s. 5. The method for monitoring channel quality in a high-speed downlink packet access system according to claim 1 or 2, wherein the preset pattern can be a predefined fixed sequence. 6. The method for monitoring channel quality in a high-speed downlink packet access system according to claim 1 or 2, wherein the preset mode can be calculated according to a predefined algorithm.

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