KR20110007990A - Method for user pairing test - Google Patents

Abstract

PURPOSE: A user fairing test method is provided to reasonably set a stress test time condition, thereby removing the need of a multi slot processing support of a mobile station. CONSTITUTION: A base station directs a stress test about a slot of a first user to a second user(503). If a stress test time conditions is fulfilled, the second user performs the stress test about the first user(504). If a channel quality of the first user and the second user coincides with preset channel quality requirements, the base station multiplexes the candidate users on the same time-frequency resources(505,507).

Description

How to test user pairing {METHOD FOR USER PAIRING TEST}

The present invention relates to wireless communication technology, and more particularly, to a user pairing test method applicable to GERAN / VAMOS system.

In recent years, as the demand for mobile voice services has soared, GSM networks are accepting rapid development. As a result, limited spectrum resources are becoming increasingly difficult to meet people's communication needs, especially in populated cities. In addition, as the GSM network device becomes aging, the expansion of the GSM network capacity is very urgent. However, from an operator's point of view, since voice service charges are gradually lowering year by year, it is necessary to reuse current hardware resources and frequency resources more efficiently. Therefore, system capacity improvement under the premise of not increasing the current system frequency resource has become a very important research field.

Multiple User Reuse One Slot (MUROS) technology is mainly applied to 3GPP GERAN (GSM / EDGE Radio Access Network). MUROS technology was officially named VAMOS (Voice Service over Adaptive Multi-user channels on One Slot) at the GERAN # 40 conference in November 2008.

GERAN / VAMOS systems need to further improve voice capacity based on reusing current network devices and radio resources. In the feasibility study phase, the candidate VAMOS method multiplexes two or more users onto one slot, presuming that call quality does not degrade. Currently, the wireless communications industry is primarily considering doubling the system voice capacity, ie, reusing two users on each slot. In one aspect, affected by this method are full-rate voice channels and half-rate voice channels including TCH / FS, TCH / HS, TCH / EFS, TCH / AFS, TCH / AHS and TCH / WFS; Associated Associated Control Channels such as Slow Associated Control Channel (SACCH) and Fast Associated Control Channel (FACCH). In another aspect, after VAMOS technology is used, an increase in the number of users in one cell will certainly result in an increase in common frequency interference and adjacent frequency interference, and also in Carrier / Interference (C / I). ) Ratio and frequency multiplexing will be reduced. Therefore, the method of reaching a compromise between decreasing frequency multiplexing and increasing slot reuse must be further studied.

Conventional candidate VAMOS solutions mainly include the following three types.

First, Co-Traffic-CHannel (Co-TCH) method

For the downlink, two channels of Gaussian Minimum Frequency-Shift Keying (GMSK) baseband modulated signal are linearly combined and then transmitted after frequency modulation and power amplification. The phase difference between these two signal channels is π / 2.

In the case of the uplink, each mobile station (MS) employs a GMSK modulation, a different training sequence (TSC) than all other mobile stations, and the two at the base station side according to a method such as joint detection. Separate multiplexed user signal channels.

Second, orthogonal sub-channel (OSC) method

In the downlink, quaternary phase-shift keying (QPSK) is employed to transmit two user signal channels, and each user signal channel at the user receiving end may be received through GMSK modulation.

For the uplink, each mobile station employs GMSK modulation, a different training sequence than all other mobile stations, and separates two multiplexed user signal channels at the base station side in the same way as interference cancellation.

Third, Adaptive Symbol Constellation mapping (ASC) method

For the downlink, the alpha-QPSK method is employed and the transmit power of the I and Q channels can be controlled through adaptive coordinated constellation mapping.

For the uplink, each mobile station employs GMSK modulation, a different training sequence than all other mobile stations, and a multi-user-multiple-input multiple-output (MU-MIMO) receiver. Demodulates the two multiplexed user signal channels at the base station.

Although there are differences in the three methods described above, in all of these two subchannels (subchannel 1 and subchannel 2) can be considered to share the same time-frequency resources. In general, subchannel 1 can support early cellular phones, and subchannel 2 can only support cellular phones with VAMOS technology, which stands for VAMOS cellular phone.

1 is a schematic diagram showing a frame structure of a conventional GSM system. As shown in Fig. 1, the GSM system employs a TDMA (Time Division Multiple Access) technique. Each TDMA frame is divided into eight slots numbered 0, 1, ..., 7. Regardless of whether they are frames or slots, they do not overlap each other. A slot is a radio resource basic unit of a GSM system. According to a specific slot allocation principle, in each frame, each mobile station can transmit a signal to the base station only through designated slots, and under periodic and synchronizing conditions, the base station transmits through each individual slot without signal confusion and interference. It is possible to receive a signal of each mobile station. On the other hand, the signals transmitted by the base station to the plurality of mobile stations are arranged in a sequence and transmitted through predetermined slots. As long as each mobile station receives a signal through its designated slot, it can distinguish the signal transmitted to it from the combined signals.

2 is a schematic diagram showing two users reusing one time-frequency resource in a conventional GERAN / VAMOS system. In circuit switch mode, VAMOS can multiplex two users on one time-frequency resource. These two users form one VAMOS pair and share the same slot number, ARFCN and TDMA frame number on the uplink and downlink.

3 is a schematic diagram showing downlink modulation of a pair of users in a conventional GERAN / VAMOS system. VAMOS subchannel 1 and VAMOS subchannel 2 of FIG. 3 are voice TCHs (Traffic CHannel) of two users, each of which is a VAMOS pair. The bits of VAMOS subchannel 1, VAMOS subchannel 2 and the corresponding combined control channel are mapped to one adaptive QPSK (AQPSK) modulation symbol (Si shown in FIG. 3). Si is transmitted after performing rotation and pulse shaping. At the receiving end, the user demodulates its own bits of the TCH and the corresponding combined control channel, and performs radio link measurement.

4 is a schematic diagram showing uplink modulation of paired users in a conventional GERAN / VAMOS system. For the uplink, two paired users in one cell employ GMSK modulation and transmit signals over the same time-frequency resource. That is, these two users have the same slot number, ARFCN and TDMA frame number. Users are distinguished by different training sequences in the data they transmit. Within one cell, users on two subchannels employ training sequences of different TSC sets. For example, a user of subchannel 1 employs a training sequence of TSC set 1, and a user of subchannel 2 employs a training sequence of TSC set 2. The receiving end of the base station employs a multi-user detection or interference cancellation technique to demodulate and decode the two received user signals, and corresponding radio link control is performed for these two users.

Although the three conventional candidate VAMOS methods described above ensure orthogonality between two multiplexed users, the inter-symbol symbols caused by the sum of the multipath propagation characteristics of the radio channel and the nonlinear characteristics of the transmitting and receiving filters. The interference will cause crosstalk between subchannels at the receiving end. This means that in the case of the downlink, two multiplexed users interfere with each other. This also means that in the uplink, orthogonality at the receiving end cannot be guaranteed because of the random phase difference that occurs between users even when there is no time-diffusibility attenuation in the channels. Since orthogonality between two subchannels cannot be guaranteed at the receiving end, inter-cell interference occurs and two multiplexed subchannels interfere with each other, resulting in poor system performance. After the system binds two users together, it is impossible to ensure that each user's wireless channel transmission quality is acceptable due to interference between subchannels, and also by adjusting the transmission power of a pair of users. It is not possible to change channel conditions quickly. In this situation, call interruption of users usually occurs, resulting in poor service quality.

Based on the above situation, at present, users with good channel conditions and high signal-to-noise ratio are mainly selected as a pair of candidate users. On the other hand, the transmit power of the selected users is strengthened to ensure that the users after pairing still have acceptable channel quality. With regard to the so-called acceptable channel quality, the user's channel quality is divided into eight classes according to GSM (different grades mean different channel quality). If the channel quality is not lower than the grade used as the threshold, the channel quality is considered to be acceptable channel quality. Even so, user pairing is still uncertain. For example, if a user's initial transmit power is not sufficient or cannot be quickly adjusted to a channel condition that the transmit power consistently meets, call interruption may occur or return from VAMOS multiplexing mode to a mode in which one user occupies one slot. Will be born.

In addition, different users face different degrees of interference at different locations, different slots, or at different frequencies, and also face different inter-channel interferences after user pairing. Therefore, it becomes very difficult to predict the interference situation.

In the Frequency Division Duplex (FDD) system, the channel conditions of the uplink and the downlink are different. In particular, after VAMOS multiplexing is introduced, the downlink employs AQPSK modulation while the uplink continues to employ GMSK modulation, so the uplink and downlink face different interference. In the uplink, the base station needs to determine the initial transmit power after user pairing. Thus, it is determined that both uplink and downlink require a stress test.

In view of the foregoing, before the system decides to tie two users on the same time-frequency resource, a pairing test, that is, allowing mobile stations of two candidate users to transmit or receive dummy data, results in a stress test mode. You need to perform a pairing test on. On the other hand, it is necessary to adjust the transmission power ratios of the two users' mobile stations so that two paired users still maintain a relatively reliable channel transmission power to lower the call interruption probability. If both uplink and downlink can meet the channel transmission quality of two paired users, pairing test is completed, two users are multiplexed on the same time-frequency resource, and unnecessary radio resources are released. .

A similar conventional pairing test method is that the base station allocates one dedicated slot to two candidate users for stress testing. Through this dedicated slot, two candidate users' mobile stations transmit or receive dummy data and send channel measurement reports. On the other hand, even in this state, the original slots of the two users remain reserved for use in transmitting or receiving the actual communication data of the two users. This method has some disadvantages. This method requires not only one additional slot for stress testing, but also all mobile stations of candidate users need to support multislot processing capability, so the method is very limited in practical systems.

Another conventional pairing test method is that a base station uses a slot of any one of two candidate users as a slot for stress testing. Through this stress test slot, the candidate user's mobile station transmits or receives dummy data and sends channel measurement reports, while the other user's original slot is reserved for use in transmitting or receiving his actual communication data. . This method does not require additional stress test slots. However, this method still requires the mobile station of the candidate user to support multislot processing capability, so its application range is limited.

The present invention provides a user pairing test method that improves system capacity and lowers system call interruption probability by implementing a user pairing test in a condition where a user's mobile station does not need to support multislot processing and no additional slot is required.

A user pairing test method applicable to a voice service over Adaptive Multi-user channels on One Slot (VAMOS) system, comprising the step of multiplexing multiple users in the same slot and presetting a stress test time condition according to the present invention, Selecting, by the base station, two users including a first user and a second user as candidate users; The base station instructing the second user to perform a stress test on the slot of the first user; When the stress test time condition is met, the second user performing a stress test on the slot of the first user and reporting a channel condition to the base station; Determining, by the base station, whether channel quality of the first user and the second user meets preset channel quality requirements according to channel conditions reported by the first user and the second user; If the channel quality of the first user and the second user does not meet the preset channel quality requirements, the base station according to the channel conditions reported by the first user and the second user the first user and the second user Adjusting a transmission power of the user; And when the channel quality of the first user and the second user meets a preset channel quality requirement, the base station multiplexes the first user and the second user on the same time-frequency resource, and the multiplexed time Releasing time-frequency resources occupied by the first user and the second user, except for frequency resources.

In addition, a user pairing test method applicable to a voice service over Adaptive Multi-user channels on One Slot (VAMOS) system, comprising the steps of multiplexing multiple users in the same slot and presetting a stress test time condition according to the present invention. The base station selecting a candidate user; The base station instructing the candidate user to perform a stress test on individual slots of the candidate user; If the stress test time condition is not met, the base station transmits voice data of each candidate user through subchannel 1 of each candidate user and dummy data through subchannel 2, and the stress test time condition. Is satisfied, the base station transmits the dummy data on both the subchannel 1 and the subchannel 2 of each candidate user, and each candidate user receives the data on subchannel 1 of the slot of the candidate user. Reporting a channel condition to the base station; Determining, by the base station, whether a channel quality of the candidate user meets preset channel quality requirements according to channel conditions reported by each candidate user; If the channel quality of each candidate user does not meet the preset channel quality requirement, the base station transmits the subchannel 1 and the subchannel 2 of each candidate user according to the channel condition reported by each candidate user. Adjusting power; And when the channel quality of each candidate user meets the preset channel quality requirement, the base station multiplexes candidate users having channel quality that meets the preset channel quality requirement on the same time-frequency resource, and the multiplexing. Releasing time-frequency resources occupied by the candidate users except for time-frequency resources.

The present invention does not need to occupy additional slot resources, and by reasonably setting the stress test time conditions, candidate users do not need to perform multislot processing, so that the user's mobile station does not need to support multislot processing. And in the situation where the user's mobile station does not need to support multislot processing and no additional slots are needed, the present invention can implement the user pairing test even in this state, increase the system capacity and reduce the probability of system call interruption. .

1 is a view showing a frame structure of a conventional GSM system,
2 is a view showing two users reuse the same time-frequency resources in a conventional GERAN / VAMOS system,
3 illustrates downlink modulation of a pair of users in a conventional GERAN / VAMOS system,
4 is a diagram illustrating uplink modulation of a pair of users in a conventional GERAN / VAMOS system,
5 is a flowchart of a first preferred user pairing test method according to an embodiment of the present invention;
6 is a flowchart of a second preferred user pairing test method according to an embodiment of the present invention;
7 is a diagram illustrating a user pairing test method when a user is in a DTX state according to the first embodiment of the present invention;
8 is a diagram illustrating a user pairing test method when a user requests a TCH voice channel according to a second embodiment of the present invention;
9 illustrates a user pairing test method when a candidate user performs a stress test through individual slots according to a third embodiment of the present invention.

In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

According to one embodiment of the present invention, the stress test time condition is preset, and the base station then performs a stress test on one candidate user for the slot of the candidate user or for the slot of another candidate user when the stress test time condition is met. Inform the user to perform and report channel conditions. Finally, the base station adjusts the transmission power of the candidate user according to the channel conditions of the candidate user, and selects two candidate users when the channel quality of the candidate user meets the channel quality requirements. Multiplex on the same time-frequency resource and release unnecessary time-frequency resources. According to the method of this embodiment, in one aspect there is no need to occupy additional slot resources, and in another aspect the candidate users do not have to perform multislot processing by reasonably setting the stress test time conditions, so that the user's mobile station There is no need to support multislot processing. As can be seen, in situations where the user's mobile station does not need to support multislot processing and no additional slots are needed, the present invention can implement a user pairing test even in this state, increasing system capacity and probing system call dropping. Decreases.

As the inventor of the present invention analyzes the actual communication process of the mobile communication system, a method of selecting a stress test time condition will be described in detail below.

Studies show that during one communication process, mobile users usually spend only 40% of their time talking and do not send voice messages most of the time. Thus, the GSM system introduces a DTX (Discontinuous Transmission) mechanism.

Functions of the DTX mechanism include:

1) The use of DTX can lower the level of interference in the system and improve the effectiveness of the system.

2) Since the DTX transmitter is used, the total transmission time is shortened, the life span of the cell is extended, and power consumption is reduced.

In order to realize DTX, Voice Activation Detection (VAD) technology must be used, so that an indicator can be presented immediately when the conversation stops.

In the DTX state, the mobile station only transmits an inherent SACCH frame and a Silence Indicator (SID). SID frames are used for "soft noise (noise reduction)" generation. Soft noise is created manually and is therefore generated regularly and periodically. When the soft noise is decoded, the listener will not care about the sound. One main purpose of using soft noise is, in one aspect, to be a system action requirement when voice should not be transmitted, and in another aspect to intentionally prevent the listener to be mistaken for a stoppage due to disconnection (ie call interruption). Is caused by. The DTX transmission mode requires only very low speed, so only 260 code bits per 480 kHz are transmitted in this mode. In comparison, in normal communication, the voice stream generates 260 code bits per 20 ms.

In a VAMOS system, DTX plays an important role in reducing interference between two users multiplexed on the same time-frequency resource in one cell. In the downlink, when the TCH channel employs DTX technology, for one VAMOS pair, if both users must transmit data, i.e. if neither user is in DTX state, the base station performs the AQPSK modulation shown in FIG. If one user's TCH channel is in the DTX state and the other user is not in the DTX state, the base station transmits GMSK modulation to the user who is not in the DTX state, and if both users' TCH channels are in the DTX state, the base station Transmits only DTX information.

Thus, the present invention provides that the candidate user may perform a stress test when the candidate user is in the DTX state and does not need to transmit the SID and SACCH, ie, "the candidate user is in the DTX state and transmits the SID and SACCH. It is proposed that a situation that does not need to be "can be selected as a stress test time condition. Specifically, there may be two conditions, that is, a candidate user may perform a stress test on a slot occupied by another candidate user and a stress test on a slot occupied by another candidate user may be performed.

In addition, when a candidate user requires a TCH channel and the system has already completed authentication and encryption for that candidate user but has not assigned time-frequency resources to that candidate user, the candidate user is placed in a slot of another candidate user. This period can be employed to perform stress tests on the body. That is, the situation where a "candidate user requires a TCH channel" may be selected as the stress test time condition.

Based on the above analysis, the present invention provides two kinds of user pairing test methods which will be described in detail below.

5 is a flowchart of a first preferred user pairing test method according to an embodiment of the present invention. This first preferred method assumes that the candidate user performs a stress test on the slot of another candidate user. As shown in FIG. 5, the method is applicable to GERAN / VAMOS systems and includes the following steps.

In step 501, a stress test time condition is preset.

In step 501, the stress test time condition preset is a situation in which the candidate user is in the DTX state and does not need to transmit the SID and SACCH in the current frame (hereinafter, referred to as the first time condition for short) or the candidate user is in the TCH channel. (Hereinafter abbreviated as second time condition).

In step 502, the base station selects two users (a first user and a second user) as candidate users.

In step 502, the base station may randomly select two users as candidate users, or may select two users having a similar channel quality to the candidate user according to the channel quality of the user.

If the stress test time condition preset is the second time condition, at this step, the base station should select one voice user and one user requesting the TCH channel as candidate users for pairing test.

In step 503, the base station instructs the second user to perform a stress test on the slot of the first user.

In step 503, in response to the first time condition, the base station may determine whether both mobile stations of the selected two users support VAMOS. If yes, the base station selects one of the two users as the second user, and if negative, the base station selects the user corresponding to the mobile station that does not support VAMOS as the second user.

Corresponding to the second time condition, the voice user is selected as the first user and the user requesting the TCH channel is selected as the second user.

At this stage, the base station may instruct the second user to perform a stress test via an assignment command (AC), and the slot and mobile allocation index offset (MAIO) of the first user included in the assignment command. A radio communication (resource) allocation index offset) or a slot of the first user and an Absolute Radio Frequency Channel Number (ARFCN) to the second user. Here, the slot in which the stress test is performed, that is, the slot of the first user, must be transmitted to the second user, and only one of the MAIO and the ARFCN is transmitted. Whether to transmit MAIO or ARFCN depends on whether the system employs a frequency hopping (hopping) mode. If the system employs the frequency hopping mode, the MAIO is transmitted. If the system does not employ the frequency hopping mode, the ARFCN is transmitted.

In a particular implementation, whether a stress test should be performed on the reserved type or reserved bit combination in the channel type and TDMA offset fields included in the channel description message (Channel Description 1, Channel Description 2, or Channel Description 3) of the assignment command. It can be used as an indicator to indicate to the candidate user, and can include the slot of the first user and the MAIO or the slot and ARFCN of the first user in the channel description message of the assignment command to be sent to the second user.

Corresponding to the first time condition, the base station may include an assignment command in the FACCH channel and transmit it to the second user.

Corresponding to the second time condition, the base station may include an assignment command in a Stand-Alone Dedicated Control Channel (SDCCH) channel and transmit it to a second user.

If the stress test time condition is met in step 504, the second user performs a stress test on the first user and reports the channel condition to the base station.

In step 504, the first user cannot make any changes and only transmits and receives data through subchannel 1 of his slot according to his original training sequence. If the stress test time condition is met, the second user transmits dummy data through subchannel 2 of the slot of the first user by using a different training sequence set than the training sequence set to which the training sequence used by the first user belongs. Or receive dummy data or transmit and receive dummy data.

In practice, if only the uplink requires a stress test, the second user only transmits dummy data on subchannel 2 of the slot of the first user, and only the downlink requires a stress test, The second user only receives on subchannel 2 of the slot of the first user, and if both uplink and downlink require a stress test, the second user downloads the dummy data on subchannel 2 of the slot of the first user. Send and receive

According to the channel conditions reported by the first user and the second user in step 505, the base station determines whether the channel quality of the first user and the second user meets the preset channel quality requirements. If yes, go to step 507; if negative, go to step 506.

Here, the channel quality requirements for the uplink and the downlink may vary depending on the actual application requirements. In other words, different channel quality requirements may be set according to actual application requirements in order to be more flexible to actual application requirements. For example, the channel quality requirement may be a setting such that the uplink and downlink channel conditions of two candidate users must reach a preset channel quality threshold, or the channel conditions of the downlink channels of two candidate users are set to a preset channel quality threshold. There may be a setting to reach, or a setting that the channel condition of the uplink of two candidate users must reach the preset channel quality threshold.

Given that the constraints on user pairing in the real system are concentrated on the downlink, it is possible to set high channel quality requirements for the downlink and low channel quality requirements for the uplink. Alternatively, considering the complexity of the pairing test procedure, it is also possible to consider only the channel quality requirements of the downlink.

In step 506, the base station adjusts the transmit power of the first user and the second user according to the channel conditions reported by the first user and the second user, and then again, step 504 is performed.

Through the determination at step 505, step 506 is performed when the current channel quality has not reached the preset requirement. Thus, after adjusting the transmit power of the first user and the second user, the method returns to step 506 to continue the stress test.

In step 507, the base station multiplexes the first user and the second user on the same time-frequency resource, and releases the time-frequency resources occupied by the first user and the second user, except for this multiplexed time-frequency resource. .

The determination in step 505 indicates that the pairing test was successful when the current channel quality reached the preset requirement. At this point, the base station multiplexes candidate users on the same time-frequency resources and releases unnecessary time-frequency resources.

In this way, the first preferred user pairing test method is terminated.

6 is a flowchart of a second preferred user pairing test method according to an embodiment of the present invention. This second preferred method assumes that the candidate user performs a stress test on his slot. As shown in FIG. 6, the method is applicable to GERAN / VAMOS systems and includes the following steps.

In step 601, a stress test time condition is preset.

In step 601, the stress test time condition preset may be that the candidate user is in the DTX state and does not transmit the SID and the SACCH in the current frame.

In step 602, the base station selects a candidate user.

In step 602, the base station may randomly select a candidate user or a user having a channel quality similar to the candidate user according to the channel quality of the user.

The number of candidate users selected may include the following two conditions.

First condition: Two candidate users are selected. The case where only two candidate users are selected indicates that these two candidate users are used as the target of the pairing test. Subsequently, the transmission powers of the two candidate users are adjusted according to channel conditions reported by these two candidate users. If the channel conditions meet the channel quality requirements, the two users are tied together.

Second condition: Two or more candidate users are selected. The case where two or more candidate users are selected indicates that the pairing relationship between the candidate users is not relatively compact. The transmission power of one candidate user may be adjusted according to channel conditions reported by the candidate user regardless of channel conditions of another candidate user. Subsequently, two users having appropriate channel conditions are selected according to the user's channel conditions.

Step 603: The base station instructs the candidate user to perform a stress test on the individual slots of the candidate user.

In this step, the base station performs the stress test on the idle bit or idle bit combination in the channel type and the TDMA offset field included in the channel description message (Channel Description 1, Channel Description 2, or Channel Description 3) of the assignment command. Can be used as an indicator to indicate to a candidate user whether or not to be. The base station then employs an indicator to instruct the candidate user to perform a stress test and report channel conditions, and sends an assignment command carried in the FACCH to the candidate user.

If the stress test time condition is not met in step 604, the base station transmits the voice data of each candidate user on subchannel 1 of each candidate user and the dummy data on subchannel 2. If the stress test time condition is met, the base station transmits dummy data to both subchannel 1 and subchannel 2 of each candidate user. Each candidate user receives data on subchannel 1 of the slot of the candidate user and reports the channel condition to the base station.

In step 605 the base station determines whether the channel quality of the candidate user meets the channel quality requirements according to the channel conditions reported by all candidate users. If yes, go to step 607; if negative, go to step 606.

If only two candidate users are selected in step 602 (called the first user and the second user), the processing in step 605 is as follows. That is, according to channel conditions reported by the first user and the second user, the base station determines whether the channel quality of the first user and the second user meets the preset channel quality requirements, and if yes, proceeds to step 607, If no, go to Step 606.

If two or more candidate users are selected in step 602, the processing in step 605 is as follows. That is, according to the channel conditions reported by each candidate user, the base station determines whether there is a candidate user that meets the preset channel quality requirements, proceeds to step 607 if positive, and selects a candidate user who has not completed the stress test if negative. Proceed to step 606.

According to the channel condition reported by each candidate user in step 606, the base station adjusts the transmit power of subchannel 1 and subchannel 2 of each candidate user and returns to step 604.

If only two candidate users are selected in step 602, the processing in step 606 is as follows. That is, according to the channel condition reported by the first user and the second user, the base station adjusts the transmission power of the subchannel 1 and the subchannel 2 of the first user and the second user and returns to step 604.

If more than one candidate user is selected in step 602, the processing in step 606 is as follows. That is, according to the channel quality reported by each candidate user, the base station adjusts the transmission power of subchannel 1 and subchannel 2 of each candidate user and returns to step 604.

In step 607 the base station multiplexes candidate users whose channel quality meets the preset channel quality requirements on the same time-frequency resources and releases the time-frequency resources occupied by the candidate users, except for these multiplexed time-frequency resources. .

If only two candidate users are selected in step 602, the processing in step 607 is as follows. That is, the base station multiplexes the first user and the second user on the same time-frequency resource, and releases the time-frequency resources occupied by the candidate users except for this multiplexed time-frequency resource.

If two or more candidate users are selected in step 602, the process in step 607 includes the following steps. That is, determining whether candidate users whose stress test is completed but not user pairing include two candidate users having channel quality that meets preset channel quality requirements, and if yes, these two candidate users Multiplexing on the same time-frequency resource, releasing time-frequency resources occupied by these two candidate users, except for this multiplexed time-frequency resource, and terminating user pairing for the two candidate users Further determining whether there are candidate users with channel quality that meets the preset channel quality requirements, and for candidate users who have not completed the stress test if there are candidate users with channel quality that meets the preset channel quality requirements. Performing 606.

In this way, the second preferred user pairing test method is terminated.

As can be seen from the above-described technical configuration of the present invention, in the user pairing test method according to the present invention, the stress test time condition is preset, and then the base station selects a candidate user when the stress test time condition is satisfied. Notify the user to perform a stress test on the candidate user's slot or another candidate user's slot and report channel conditions. Finally, the base station adjusts the transmission power of the candidate user according to the candidate user's channel conditions, When the channel quality meets the channel quality requirements, two candidate users are multiplexed onto the same time-frequency resources and release unnecessary time-frequency resources. According to the method of this embodiment, in one aspect there is no need to occupy additional slot resources, and in another aspect the candidate users do not have to perform multislot processing by reasonably setting the stress test time conditions, so that the user's mobile station There is no need to support multislot processing. As can be seen, in situations where the user's mobile station does not need to support multislot processing and no additional slots are needed, the present invention can implement a user pairing test even in this state, increasing system capacity and probing system call dropping. Decreases.

Hereinafter, the present invention will be described in detail with reference to three embodiments.

<First Embodiment>

A first embodiment of the present invention provides a user pairing test method when a user is in a DTX state. This method is applicable to GERAN / VAMOS systems.

7 is a schematic diagram illustrating a user pairing test method when a user is in a DTX state according to the first embodiment of the present invention. As shown in Fig. 7, it is assumed that MS1 and MS2 are voice users occupying time slots TS1 and TS5, respectively. As the load on the system gets worse, the base station needs to assign users with better channel conditions on the same slots and the same frequency resources. To ensure that channel conditions and user call quality are not affected after user pairing, the uplinks of the two candidate users are determined by performing pairing tests before actually pairing and adjusting the transmit power of the two candidate users using a stress test method. It is necessary to ensure that both the and the downlink have acceptable channel conditions.

In a real system, not all mobile stations support multislot processing capability. In order to extend the application range of the user pairing test method according to the present invention, this embodiment proposes to start the user pairing test when the candidate user is in the DTX state and does not need to transmit the SID and SACCH in the current frame. do.

The base station uses MS1 and MS2 as two candidate users. If the mobile stations of two candidate users support VAMOS, the slot of either candidate user of the two candidate users is selected as the slot used for the stress test. In addition, the slot of the initial cellular phone (i.e., the legacy user) is selected as the slot used for the stress test. In the following, it is assumed that the slot of MS1 is selected as the slot used for the stress test. The base station transmits an assignment command to the MS2 via the FACCH, and may use the idle bit 7 in the channel type and TDMA offset fields of the channel description message as an indicator for indicating whether or not to perform a stress test. For example, bit 7 equals 0 to indicate that no stress test is performed and bit 7 equals 1 to indicate that the stress test starts. The slot number and MAIO value or ARFCN value used during the stress test are included in the channel description message. When MS2 is in the DTX state and there is no need to transmit the SID and SACCH in the current frame, dummy data is transmitted or received via TS1 of MS1.

In the Channel Type and TDMA Offset fields, bit 6 is also a pause bit and can be used as an indicator to indicate whether or not a stress test is to be performed. For example, bit 6 equals 0 to indicate that no stress test is performed and bit 6 equals 1 to indicate that the stress test starts. Obviously, in practical applications, bit 7 and bit 6 may be combined integrally as an indicator to indicate whether or not a stress test is to be performed. In addition, it is also possible to define many other ways of using the idle bit in the channel description message as an indicator to indicate whether or not a stress test is to be performed. However, in order not to lengthen the present invention, other methods will not be described here, but they are still within the protection scope of the present invention.

In the downlink, MS1 receives its voice data via TS1. On the other hand, when MS2 is in the DTX state and it is not necessary to transmit SIN and SACCH in the current frame, MS2 receives dummy data transmitted by the base station through TS1. In the VAMOS downlink modulation mode, voice data sent to MS1 and dummy data sent to MS2 are modulated by AQPSK (or AQM, which is not yet known), and MS1 and MS2 have their respective subchannels Receive data via In general, to avoid additional signaling overhead, MS1 may receive data on a legacy sub-channel without changing to MS1. That is, MS1 uses subchannel 1. Since MS2 receives dummy data through subchannel 2, MS2 must be a VAMOS type mobile phone. After receiving the dummy data, MS2 checks the radio channel quality and reports the measurement result of the dummy data through TS1. The base station adjusts the transmission power of the two subchannels according to the measurement results of two users so that both subchannels are an acceptable channel condition.

In the uplink, MS1 transmits its voice data through TS1. On the other hand, MS2 also transmits dummy data modulated by GMSK through TS1 in the idle frame. In general, to avoid changing the transmission mode of MS1, the training sequence of MS1 is not changed, and MS2 transmits dummy data by using the training sequence in the corresponding TSC set 2. After receiving the data transmitted by two users through TS1, the base station adjusts the transmission power of the two users for TS1 according to the radio channel quality so that the uplink channel conditions are acceptable for both users.

When both uplink and downlink of two candidate users become acceptable channel conditions, the base station assigns two users on TS1, releases the slot resources originally occupied by MS2, and then completes the pairing test procedure. Obviously, two users may be allocated on a slot of MS2 or on another slot, and unnecessary resources are released.

During the pairing test procedure, the base station signals the MS1 to send or receive dummy data through the slot of MS2 when MS1 is in the DTX state and does not need to transmit the SID and SACCH in the current frame. Can be sent. In other words, one candidate user transmits or receives dummy data through another user's slot to increase the efficiency of the stress test, unless the candidate user is in the DTX state and does not need to transmit the SID and SACCH in the current frame.

During the pairing test procedure, considering the complexity, it is also possible to perform a stress test only on the downlink or only on the uplink. When determining the pairing test, it is also possible that only the channel quality requirements of the downlink are met, only the channel quality requirements of the uplink are met, or both the channel quality requirements of the uplink and downlink are met.

In the user pairing test method according to the first embodiment, since the mobile station of the user only needs to process data through one slot, the mobile station does not need to support the multislot transmission capability, and thus the application range of the method of this embodiment is expanded. .

The basic concept of the first embodiment is the following steps, i.e., when the user is in the DTX state and does not need to transmit the SID and SACCH in the current frame, performing a pairing test on the slot for the stress test, the stress test Transmitting or receiving data for a slot for the UE and reporting the measurement result, the base station adjusting the transmission power of each subchannel according to the measurement result report to maintain the transmission power at an acceptable level, uplink and downlink Terminating the pairing test and releasing unnecessary resources when all of the links are in an acceptable channel condition. Thus, in a situation where the user's mobile station does not need to support multislot processing and no excess slots are needed, the user pairing test is realized, the system capacity is increased, and the probability of system call interruption is low.

In addition to the implementation manner of the first embodiment of the present invention, according to the main concept of this embodiment, many other methods of performing a stress test when the user is in the DTX state and providing an indicator in the channel description message indicating whether or not the stress test is performed Can be defined. However, in order not to lengthen the present invention, other methods will not be described here, but they are still within the protection scope of the present invention.

Second Embodiment

The second embodiment provides a user pairing test method when a user requests a TCH voice channel. This method is applicable to GERAN / VAMOS systems.

8 is a schematic diagram illustrating a user pairing test method when a user requests a TCH voice channel according to a second embodiment of the present invention. As shown in Fig. 8, it is assumed that MS1 is a voice user and occupies time slot TS1. As the load on the system gets worse, the base station needs to assign users with better channel conditions on the same slots and the same frequency resources. To ensure that channel conditions and user call quality are not affected after user pairing, the uplinks of the two candidate users are determined by performing pairing tests before actually pairing and adjusting the transmit power of the two candidate users using a stress test method. It is necessary to ensure that both the and the downlink have acceptable channel conditions.

In a real system, not all mobile stations support multislot processing capability. In order to extend the application range of the user pairing test method according to the present invention, this embodiment proposes that the base station initiates the user pairing test when the user starts to request the TCH channel. Assuming that MS2 is requesting a TCH channel and has completed authentication and encryption, the base station sends assignment command signaling to MS2 via SDCCH, and the slot number and MAIO value or slot number and ARFCN that are also available to MS2 in the channel description message. Include it. MS1 and MS2 are two candidate users and MS2 transmits or receives dummy data through TS1 occupied by MS1.

In the downlink, MS1 receives its voice data via TS1. On the other hand, MS2 also receives dummy data transmitted by the base station through TS1. In the VAMOS downlink modulation mode, voice data sent to MS1 and dummy data sent to MS2 are modulated by AQPSK (or AQM, which is not yet known), and MS1 and MS2 have their respective subchannels Receive data via In general, to avoid additional signaling overhead, MS1 may receive data on a legacy sub-channel without changing to MS1. That is, MS1 uses subchannel 1. Since MS2 receives dummy data through subchannel 2, MS2 must be a VAMOS type mobile phone. After receiving the dummy data, MS2 checks the radio channel quality and reports the measurement result of the dummy data through TS1. The base station adjusts the transmission power of the two subchannels according to the measurement results of two users so that both subchannels are an acceptable channel condition.

In the uplink, MS1 transmits its voice data through TS1. MS2 also transmits dummy data modulated by GMSK through TS1. In general, to avoid changing the transmission mode of MS1, the training sequence of MS1 is not changed, and MS2 transmits dummy data by using the training sequence in the corresponding TSC set 2. After receiving the data transmitted by two users through TS1, the base station adjusts the transmission power of the two users for TS1 according to the radio channel quality so that the uplink channel conditions are acceptable for both users.

When both uplink and downlink of two candidate users become acceptable channel conditions, the base station assigns two users on TS1 and the pairing test procedure is completed. Obviously, two users may be assigned on different slots and unnecessary resources are released.

During the pairing test procedure, the base station transmits assignment command signaling over the SDCCH and may use idle bit 7 in the channel type and TDMA offset fields of the channel description message as an indicator to indicate whether or not to perform a stress test. . For example, bit 7 equals 0 to indicate that no stress test is performed and bit 7 equals 1 to indicate that the stress test starts. Specifically, the slot number and MAIO value or ARFCN value used during the stress test are included in the channel description message.

During the pairing test procedure, considering the complexity, it is also possible to perform a stress test only on the downlink or only on the uplink. When determining the pairing test, it is also possible that only the channel quality requirements of the downlink are met, only the channel quality requirements of the uplink are met, or both the channel quality requirements of the uplink and downlink are met.

In the user pairing test method according to the second embodiment, since the mobile station of the user only needs to process data through one slot, the mobile station does not need to support the multislot transmission capability, and thus the application range of the method of this embodiment is expanded. .

The basic concept of the second embodiment is the following steps: performing pairing test for one user and one voice user requesting the TCH channel, transmitting or receiving data for the slot occupied by the voice user. Reporting the measurement results, adjusting the transmit power of each subchannel to maintain the transmit power at an acceptable level, terminating the pairing test when both uplink and downlink are acceptable channel conditions and removing unnecessary resources. Releasing. Thus, in a situation where the user's mobile station does not need to support multislot processing and no excess slots are needed, the user pairing test is realized, the system capacity is increased, and the probability of system call interruption is low.

In addition to the implementation manner of the second embodiment of the present invention, according to the main concept of this embodiment, many other methods of performing a stress test when a user requests a TCH channel and providing an indicator in the channel description message indicating whether or not the stress test is performed Can be defined. However, in order not to lengthen the present invention, other methods will not be described here, but they are still within the protection scope of the present invention.

Third Embodiment

A third embodiment of the present invention provides a user pairing test method when candidate users perform a stress test on their respective slots. This method is applicable to GERAN / VAMOS systems.

9 is a schematic diagram illustrating a user pairing test method when a candidate user performs a stress test on an individual slot according to a third embodiment of the present invention. As shown in Fig. 9, it is assumed that MS1 and MS2 are voice users occupying time slots TS1 and TS5, respectively.

The base station selects MS1 and MS2 as two candidate users. The base station transmits signaling to the MS1 and the MS2 via the FACCH, and uses the idle bit 7 in the channel type and TDMA offset fields of the channel description message as an indicator for indicating whether or not to perform a stress test. For example, bit 7 equals 0 to indicate that no stress test is performed and bit 7 equals 1 to indicate that the stress test starts.

Employing the AQPSK modulation mode, the base station transmits voice data on subchannel 1 and dummy data on subchannel 2. When the user is in the DTX state and does not need to transmit the SID and SACCH in the current frame, the base station still employs the AQPSK modulation mode to transmit dummy data simultaneously on subchannel 1 and subchannel 2. In other words, since the transmission of dummy data continues in the user's idle frame, the downlink does not need to convert to GMSK modulation mode to transmit the dummy data, and furthermore, the user may receive a stress test in the idle frame. It is advantageous to obtain more accurate pairing test results.

User 1 and User 2 receive data only through subchannel 1 of TS1 and TS5, respectively, and do not process dummy data transmitted through subchannel 2. Through subchannel 1, voice data transmitted in the non-DTX state is dummy data and dummy data transmitted in the DTX state. User 1 and User 2 report the channel condition to the base station according to the received data. The base station adjusts the transmission power of subchannel 1 and subchannel 2 according to the channel conditions of user 1 and user 2.

If both User 1 and User 2's channel conditions meet certain channel quality requirements (set by the system), User 1 and User 2 are multiplexed on the same time-frequency resource, and unnecessary resources are released.

During the pairing test procedure, considering the complexity, it is possible to perform only the downlink stress test.

In the user pairing test method according to the third embodiment, since the mobile station of the user only needs to process data through one slot, the mobile station does not need to support the multislot transmission capability, and thus the application range of the method of this embodiment is expanded. .

The basic concept of the third embodiment is to continue the stress test for the slot occupied by the user when the user is in the DTX state and does not need to transmit the SID and SACCH in the current frame during the next step, ie, pairing test. Step, the user receiving the dummy data transmitted by the base station through subchannel 1 and reporting the measurement result; and according to the measurement result report so that the transmission power meets specific channel quality requirements, Adjusting the transmit power, multiplexing User 1 and User 2 on the same time-frequency resource when the channel conditions of User 1 and User 2 meet certain channel quality requirements, and ending the pairing test do. Thus, in a situation where the user's mobile station does not need to support multislot processing and no excess slots are needed, the user pairing test is realized, the system capacity is increased, and the probability of system call interruption is low.

In addition to the implementation manner of the third embodiment of the present invention, in accordance with the main concept of this embodiment, when the user is in the DTX state, the channel description is indicated by the indicator for indicating whether or not to perform the stress test on the slot occupied by the user. Many other ways of providing within a message can be defined. However, in order not to lengthen the present invention, other methods will not be described here, but they are still within the protection scope of the present invention.

Although embodiments of the present invention have been described with reference to the illustrated drawings as described above, those skilled in the art to which the present invention pertains may realize the present invention in other specific forms without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not limiting.

Claims (17)

A user pairing test method applicable to a Voice service over Adaptive Multi-user channels on One Slot (VAMOS) system, comprising the step of multiplexing multiple users in the same slot and presetting a stress test time condition,
The base station selecting two users including a first user and a second user as candidate users;
The base station instructing the second user to perform a stress test on the slot of the first user;
When the stress test time condition is met, the second user performing a stress test on the slot of the first user and reporting a channel condition to the base station;
Determining, by the base station, whether channel quality of the first user and the second user meets preset channel quality requirements according to channel conditions reported by the first user and the second user;
If the channel quality of the first user and the second user does not meet the preset channel quality requirements, the base station according to the channel conditions reported by the first user and the second user the first user and the second user Adjusting a transmission power of the user; And
If the channel quality of the first user and the second user meets a preset channel quality requirement, the base station multiplexes the first user and the second user on the same time-frequency resource, and the multiplexed time- And releasing time-frequency resources occupied by the first user and the second user except frequency resources. The method of claim 1, wherein the stress test time condition,
The second user is in a Discontinuous Transmission (DTX) state and the second user is to transmit a Silence Indicator and a Slow Associated Control Channel (SACCH) in the current frame. User pairing test method, characterized in that it does not need to. The method of claim 1, wherein the stress test time condition,
And the second user requests a voice traffic channel (TCH). According to any one of claims 1 to 3, wherein the selection process,
One of the step of the base station randomly selecting two users as the candidate user and the base station selecting two users having a similar channel quality as the candidate user according to the channel quality of the user. Characterized by the user pairing test method. The method of claim 2, wherein the indicating process comprises:
Determining, by the base station, whether both mobile stations of the two users support VAMOS;
If both mobile stations of the two users support VAMOS, selecting one of the two users as the second user; And
If both mobile stations of the two users do not support VAMOS, selecting a user corresponding to the mobile station that does not support VAMOS as the second user. The mobile station of claim 3, wherein the mobile station of the second user comprises:
User pairing test method, characterized in that it supports VAMOS. The method of claim 1, wherein the instructing process comprises:
Instructing, by the base station, a candidate user to perform the stress test through an assignment command; And
The slot and Mobile Allocation Index Offset (MAIO) of the first user or the slot and Absolute Radio Frequency Channel Number (ARFCN) of the first user are included in the assignment command. And including the step of including the user pairing test method. 8. The candidate user of claim 7, wherein the candidate test determines whether the stress test should be performed on a reserved bit or a reserved bit combination in a channel type and a time division multiple access (TDMA) offset field in a channel description message of the assignment command. And using the slot of the first user and the slot of the MAIO or the slot of the first user and ARFCN in the channel description message of the assignment command. 8. The assignment command of claim 7, wherein the stress test time condition is a condition that the second user is in the DTX state and the second user does not need to transmit the SID and SACCH in the current TDMA frame. Transmitted to the second user through a fast associated control channel (FACCH),
When the stress test time condition is a condition that the second user requires the TCH, the assignment command is transmitted to the second user through a Stand-Alone Dedicated Control Channel (SDCCH). How to test user pairing. The method of claim 1, wherein the reporting process comprises:
Transmitting dummy data through subchannel 2 of the first user by using a training sequence set different from the training sequence set to which the training sequence used by the first user belongs; User receiving pairing method comprising the steps of receiving and transmitting and receiving the dummy data. The method according to any one of claims 1 to 3, wherein the preset channel quality requirement,
The uplink and downlink channel conditions of the two candidate users must reach a preset channel quality threshold, the downlink channel conditions of the two candidate users must reach a preset channel quality threshold, and And wherein at least one of the channel conditions of the uplinks of the two candidate users must reach a preset channel quality threshold. A user pairing test method applicable to a Voice service over Adaptive Multi-user channels on One Slot (VAMOS) system, comprising the step of multiplexing multiple users in the same slot and presetting a stress test time condition,
The base station selecting a candidate user;
The base station instructing the candidate user to perform a stress test on individual slots of the candidate user;
If the stress test time condition is not met, the base station transmits voice data of each candidate user through subchannel 1 of each candidate user and dummy data through subchannel 2, and the stress test time condition. Is satisfied, the base station transmits the dummy data on both the subchannel 1 and the subchannel 2 of each candidate user, and each candidate user receives the data on subchannel 1 of the slot of the candidate user. Reporting a channel condition to the base station;
Determining, by the base station, whether a channel quality of the candidate user meets preset channel quality requirements according to channel conditions reported by each candidate user;
If the channel quality of each candidate user does not meet the preset channel quality requirement, the base station transmits the subchannel 1 and the subchannel 2 of each candidate user according to the channel condition reported by each candidate user. Adjusting power; And
If the channel quality of each candidate user meets the preset channel quality requirement, the base station multiplexes candidate users having channel quality that meets the preset channel quality requirement on the same time-frequency resource, and the multiplexed Releasing time-frequency resources occupied by the candidate users except for time-frequency resources. The method of claim 12, wherein the stress test time condition,
The candidate user is in a Discontinuous Transmission (DTX) state and the candidate user needs to transmit a Silence Indicator and a Slow Associated Control Channel (SACCH) in the current frame. User pairing test method, characterized in that it includes nothing. The method of claim 13, wherein the candidate user selected in the selection process is a first user and a second user,
The determining may include determining whether the channel quality of the first user and the second user meets preset channel quality requirements according to channel conditions reported by the first user and the second user. If the channel quality of the first user and the second user meets the preset channel quality requirements, the process proceeds to the releasing process, and the channel quality of the first user and the second user does not meet the preset channel quality requirements. Otherwise proceeding to the adjusting process,
The adjusting may include adjusting, by the base station, transmission powers of subchannels 1 and 2 of the first user and the second user according to channel conditions reported by the first user and the second user. Including,
The releasing may include: the base station multiplexing the first user and the second user on the same time-frequency resource, except for the multiplexed time-frequency resource, by the first user and the second user. Releasing the occupied time-frequency resources. The method of claim 13, wherein the selection process comprises two or more candidate users selected.
The determining may include determining, according to channel conditions reported by the candidate users, whether there is a candidate user having a channel quality that meets the preset channel quality requirement, and matching the preset channel quality requirement. If there is a candidate user having channel quality, the process of terminating and releasing the stress test for the candidate user proceeds. If there is no candidate user having a channel quality that satisfies the wounded preset channel quality requirement, the stress test is not terminated Proceeding to the adjustment process for a candidate user,
The adjusting may include adjusting, by the base station, transmission power of subchannel 1 and subchannel 2 of each corresponding candidate user according to channel conditions reported by the candidate users and returning to the reporting. and,
The releasing step may include determining whether candidate users whose stress test is terminated but user pairing is not completed include two candidate users having a channel quality meeting a preset channel quality requirement, and the candidate user. Multiplexing the two candidate users on the same time-frequency resource, and releasing the time-frequency resources occupied by the two candidate users, except for the multiplexed time-frequency resource. And terminating user pairing for the two candidate users, determining whether there is a candidate user having a channel quality that meets the preset channel quality requirement, and channel quality that meets the preset channel quality requirement. If you have a candidate user with the stress test For the candidate user is not a user fee paired test method includes performing the process of the adjustment. The method of claim 12, wherein the selecting is performed.
Randomly selecting a user as the candidate user by the base station, or selecting a user having a channel quality similar to the candidate user according to the channel quality of the user. The method of claim 12, wherein the instructing process comprises
The channel type in the channel description message of the Assignment Command and the Reserved Bit or Reserved Bit combination in the Time Division Multiple Access (TDMA) Offset field are used as indicators to indicate to the candidate user whether a stress test should be performed. Doing;
Instructing the candidate user to perform the stress test and report the channel condition through the assignment command; And
And transmitting the assignment command through a fast associated control channel (FACCH).

Images