WO2011082526A1

WO2011082526A1 - Method and device for frequency spectrum share in different wireless communication systems

Info

Publication number: WO2011082526A1
Application number: PCT/CN2010/070052
Authority: WO
Inventors: 邱吉刚; 杨峰; 徐斌阳
Original assignee: 上海贝尔股份有限公司; 阿尔卡特朗讯公司
Priority date: 2010-01-07
Filing date: 2010-01-07
Publication date: 2011-07-14
Also published as: WO2011082526A8; CN102696255A; CN102696255B

Abstract

The present invention discloses a method and a device for frequency spectrum share between a base station and at least one of other base stations. All of the base stations belong to different wireless communication systems separately. The method includes: a. the base station and at least one of other base stations select a time window separately from multiple reserved time windows to prepare for sending reservation signal and at least one of other reservation signals, wherein the reservation signal contains priority level information of the base station, and the at least one of other reservation signals contains priority level information of at least one of other base stations; b. the base station obtains the priority level information contained in the at least one of other reservation signals, and compares the priority level contained in the reservation signal with the priority level contained in the at least one of other reservation signals; c. if the priority level contained in the reservation signal is higher than the priority level contained in the at least one of other reservation signals, the base station sends a concomitant signaling message in a concomitant signaling sending time segment, which is after the multiple reserved time windows; otherwise, the base station pauses the sending of the concomitant signaling message.

Description

Method and device for frequency sharing in different wireless communication systems

The present invention relates to wireless communications, and more particularly to mechanisms for spectrum sharing in wireless communication systems having different physical layer technologies. Background technique

Recently, frequency sharing technology has attracted a lot of attention because it can alleviate the lack of frequency. On the one hand, in the licensed band, the frequency sharing can be used to cause the slave device to utilize the spectrum band of the master device in a random manner. For example, the IEEE 802.22 system has used the TV band as a shared target band to implement a point-to-multipoint (P-MP) wireless area network (WRAN). In the unlicensed band, spectrum sharing technology can achieve the coexistence of multiple wireless systems. Improving frequency usage. For example, the IEEE 802.16h working group is defining improved mechanisms based on the IEEE 802.16 standard, such as policy and media access control enhancements to achieve inter-system coexistence. However, as the use of unlicensed bands increases, Additional interference and coexistence issues.

According to whether information exchange between wireless systems is necessary, the frequency sharing mechanism can be divided into two categories: collaborative mode and non-cooperative mode. In the collaborative mode, the wireless system can share information including IP addresses, channel states, and the like with each other using a wireless interface or other communication link. In general, the cooperative mode can achieve higher spectrum utilization than the non-cooperative mode.

However, due to the non-exclusive nature of the unlicensed bands, multiple systems using different physical layer technologies (hereinafter referred to as PHY technology) may operate in the same region at the same time in the same frequency band. For example, IEEE 802.il (ie compatible wireless LAN WLAN), Bluetooth devices, home RF solutions, cordless phones, etc., are currently crowded in the 2.4 GHz band. In this case, it is important to design a communication mechanism that is viable in these systems using different PHY technologies, and then use a coordinated interference resolution mechanism to achieve better coexistence.

Currently, the IEEE 802.16h group has specified a technique for applying different PHY technologies. The communication mechanism of the system, pre-defined the reserved short time slots at the end of the DL (downlink) subframe. The short time slot is referred to as CSI (Coexistence Signaling Interval), in which each base station (BS) identifies itself to the neighboring system, and Figure 1 shows the coexistence signaling interval allocation in the CX frame. The shared channel includes a plurality of CX frames, and each CX frame is composed of 4 MAC frames. Each CX frame is subdivided into specific subframes including master, slave, and shared frames. For an originating base station (IBS), the corresponding CSI is called ICSI, which is allocated in the shared frame of the CX frame. IBS uses ICSI to broadcast coexisting signaling messages to its neighboring systems. By cooperating with other BSs, the IBS will obtain its OCSI, which is the coexistence signaling interval assigned to one of the three non-shared frames in the CX frame. Once the BS has initiated the working phase and declares its primary frame, the BS will occupy the OSCI within the primary frame and release the ICSI described above for the new IBS.

Since several systems that use frequency sharing use different PHY technologies, messages used to carry frequency-shared information (including coexisting signaling messages, etc.) between these systems need to be transmitted by energy keying in the time domain. Whether the energy power during the CSI duration is greater than a predetermined threshold is expressed as information bit "1" or "0". According to the 802.16h specification, a CSI sequence consisting of 256 slots should start at the first CX frame of every 256 CX frame in each system. The CSI sequence should always start with 8 bits 1 (sequence start) and end with 8 bit 0 (end of sequence). Each CSI sequence shall have an 8-bit additional cyclic redundancy check CRC to verify the correctness of the information carried in the CSI sequence. The conventional CSI infrastructure is shown in Figure 2.

Although the exclusive allocation of OCSI can resolve information conflicts in several OCSIs, the traditional CSI allocation method defined in 802.16h does not guarantee that no conflicts will occur in ICSI. When two or more IBSs wish to enter a coexisting community, they will start transmitting coexistence signaling messages at the first CX frame of every 256 CX frame in each system since they do not know each other's existence. In this case, their CSI sequences will collide with each other, and the neighboring system cannot successfully obtain the information of the IBS through the energy detection method. Therefore, these IBSs will resend their coexistence messages in the next 256CX frame, so collisions in the ICSI sequence sent from these IBSs will occur again. As a result, no IBS can go to other The OBS sends any information so that it cannot share channels with other OBSs.

As described above, when more than one IBS wants to join a coexistence community, there is a conflict of coexistence of signaling messages during ICSI, so that it cannot communicate with "neighbors". Summary of the invention

In order to solve the above problems, the present invention proposes an optimized communication mechanism in a system having different PHY technologies, which can effectively solve the conflict problem of PHY signaling messages. This communication mechanism, referred to as Coexistence Signaling with Collision Resolution Policy (CS-CR), introduces a backoff scheme and a pre-announcement procedure with a specific priority of IBS in the conventional CSI mechanism. In one aspect, each IBS base station needs to transmit an additional energy coded signal (referred to herein as a reservation signal) to reserve subsequent transmission opportunities before transmitting the coexistence signaling message. The content of the reservation signal contains the specific priority of each IBS access ICSI. On the other hand, a competition window having an arbitrary length is used to avoid collision of reservation signals from different IBSs.

To this end, the present invention provides a method for frequency sharing between a base station and at least one other base station, wherein all base stations belong to different wireless communication systems, the method comprising: a. the base station and the at least One other base station selects a time window from a plurality of reserved time windows to prepare a transmission reservation signal and at least one other reservation signal, the reservation signal includes priority information of the base station, and the at least one other reservation signal includes Priority information of the at least one other base station; b. the base station obtains priority information included in the at least one other reservation signal, and compares priorities included in the reservation signal and the at least one other reservation signal And c. a coexistence signaling transmission time of the base station after the plurality of reserved time windows in a case where a priority included in the reservation signal is greater than a priority included in the at least one other reservation signal The segment transmits a coexistence signaling message, otherwise the transmission of the coexistence signaling message is suspended.

In an embodiment in accordance with the invention, step b further comprises the base station obtaining a priority of the at least one other base station by scanning a power level of a reserved time window selected by the at least one other base station. Preferably, the method according to an embodiment of the present invention further comprises: in a time window selected by the base station, if the priority of the base station is greater than a priority of the at least one other base station, the base station sends the reservation signal.

Preferably, the method according to the embodiment of the present invention further comprises: in a time window selected by the base station, if the priority of the base station is less than the priority of the at least one other base station, the base station suspends transmitting The reservation signal is described.

According to an embodiment of the invention, the priority of the base station depends on the number of coexistence signaling messages that the base station has experienced.

Further, the priority of the base station will also depend on the particular communication requirements of the base station, the particular communication requirements including at least one of military, medical, or emergency communication requirements.

Preferably, if the base station suspends transmission of its own coexistence signaling message during the subsequent coexistence signaling transmission period by comparison of priorities, the priority of the base station is increased by one.

In another aspect, the present invention also provides a base station of a wireless communication system, wherein the base station performs frequency sharing with at least one other base station belonging to another wireless communication system, and the base station includes: a. a time window selecting device, configured to: Selecting a time window from a plurality of reserved time windows to prepare a transmission reservation signal, wherein the reservation signal includes priority information of the base station; b. priority comparison means, configured to obtain an appointment sent by the other base station a priority information included in the signal, and comparing a priority of the base station with a priority of the other base station; and C. a coexistence signaling control device, wherein the priority included in the reserved signal is greater than In the case of the priority included in the other reservation signal, the coexistence signaling message is transmitted in the coexistence signaling transmission period after the reserved time window, otherwise, the transmission of the coexistence signaling message is suspended.

In an embodiment in accordance with the invention, the priority comparison means is further configured to obtain a priority of the other base station by scanning a power level of a reserved time window selected by the other base station.

Preferably, the base station according to an embodiment of the present invention further includes a reservation signal transmission control device, the device configured to: if the base is within a time window selected by the base station If the priority of the station is greater than the priority of the other base station, the base station sends the reservation signal; if the priority of the base station is less than the priority of the other base station, the base station suspends transmitting the reservation signal , and increase its priority accordingly.

According to an embodiment of the invention, the priority of the base station depends on the number of coexistence signaling messages that the base station has experienced, or depends on the specific communication requirements of the base station, the specific communication requirements including military, medical or emergency communication requirements At least one of them.

In another aspect, the invention also relates to a computer program product in which computer instructions for performing the method according to the invention are stored. DRAWINGS

Other objects and advantages of the present invention will become more apparent and appreciated from the description of the appended claims appended claims

1 shows a coexistence signaling interval CSI allocation in a CX frame according to the prior art; FIG. 2 shows a construction of a CSI sequence according to the prior art;

Figure 3 illustrates an ICSI sequence configuration in accordance with an embodiment of the present invention;

4 is a flow chart showing a base station transmitting an ICSI sequence according to an embodiment of the present invention; FIG. 5 is a schematic diagram showing three base stations transmitting CSI sequences according to an embodiment of the present invention; FIG. 6 is a block diagram showing a base station structure according to the present invention. . detailed description

Figure 3 illustrates an ICSI sequence configuration in accordance with an embodiment of the present invention. According to the IEEE 802.16h specification, coexistence signaling is mainly used to transmit BS_NURBC messages and BSD messages, and their maximum length is 192 bits. As mentioned above, the length of the CSI sequence defined in 802.16h is 256 bits. Except for the 8-bit CRC, the 8-bit start sequence and the 8-bit end sequence, there are still 40 remaining bits that are not used. Figure 3 shows the optimized CSI sequence construction according to the new CS-CR mechanism.

As shown in Figure 3, the entire 256-bit ICSI sequence consists of two parts: 32ICSI is used to transmit reservation signals from different IBS. These 32 ICSIs are in turn divided into four super ICSIs, each super ICSI consisting of eight ICSIs and used to send a reservation signal. Each super CSI should start with 2 bits "1" and 2 bits "0", indicating the beginning of the super CSI, and the remaining 4 bits indicate the specific priority of the IBS. The specific priority of the IBS can be set depending on many factors. For example, an IBS with a particular military, medical, or emergency communication can be preset to have a high priority value. In an embodiment of the invention, as a typical example, the priority of the IBS may be set according to the number of ICSI sequences that the IBS has experienced. For example, if an IBS has no chance or cannot send its own coexistence signaling within two ICSI sequences (ie 10.24 seconds) due to a collision, its priority will be set to 2. The greater the number of ICSI experienced by the IBS (which means that the IBS has spent more time transmitting coexistence signaling, but none succeeded), then the more priority the IBS gets to send its own coexistence signaling high.

It should be noted that, in the embodiment of the present invention, 32 bits out of 40 bits are used, and these 32 ICSIs are further divided into 4 super CSIs, and each super CSI is composed of 8 ICSIs and used to transmit a reservation signal. However, the manner in which the super CSI is divided is not limited to this. The more the number of super CSIs, the lower the probability of collision of IBS messages, and the less information transmitted accordingly. Conversely, the fewer the number of super CSIs, the greater the probability that IBS messages will collide. The more information is transmitted accordingly. The number of super CSIs can be dynamically set according to the scenario in the actual application. Herein, preferably, the number of super CSIs is selected to be four.

4 shows a flow diagram of a base station transmitting a CSI sequence in accordance with an embodiment of the present invention. As shown in step 401, after synchronization by GPS or other distributed synchronization mode, each IBS arbitrarily selects one of the four super CSIs in preparation for transmitting the reservation signal. In this embodiment, the value of the last 4 bits of the selected super CSI is set according to the number of ICSI sequences that the IBS has experienced. In step 402, the IBS needs to scan the power energy levels of other super CSIs to obtain the priority of other IBSs. Next, in step 403, the IBS compares its own priority with the priority of other IBSs. If the priority of the other IBS is greater than its own priority, then in step 404, the transmission of its own reservation signal is suspended until the next ICSI sequence. If not, then in step 405, the IBS will send its own reservation signal within the pre-selected super CSI. Next, in step 406, the IBS continues to scan the power levels of other super CSIs and compares their own priorities with those of other IBSs. As shown in step 407, after completing the power level sweep of the four super CSIs, the IBS will determine whether it wants to transmit its own coexistence signaling within the next 224 ICSI by comparing the priorities. If the priority of the IBS is highest in all IBSs, as shown in step 409, the IBS will send its own coexistence signaling in the subsequent 224-bit ICSI. Otherwise, as shown in Figure 408, it will suspend the transmission of its own signaling message within the next 224-bit ICSI, while its own priority is automatically incremented by 1, indicating that the IBS has experienced another ICSI sequence but failed to send its own Coexisting signaling, but its priority is increased by one over the last time the ICSI sequence is sent.

The SS (client terminal equipment) of the OBS that successfully receives the coexistence signaling will report the contents of the coexistence signaling message to their OBS. Next, the neighboring OBS will discover the IBS in the IP network after receiving the SS report of the signaling. Next, the IBS and OBS begin further negotiation for frequency sharing. After negotiating with multiple OBSs, the IBS will acquire a periodic interference-free OCSI and become an OBSS, after which it will stop using the current ICSI.

In order to better understand the present invention, in Fig. 5, a process of transmitting coexistence signaling is shown by taking three base stations as an example. In this example, it is assumed that the priorities of the three base stations IBS1, IBS2, IBS3 are initially 0, 1, and 2, respectively. That is, IBS 2 failed to send its own coexistence signaling in the previous ICSI sequence according to the number of ICSI sequences that IBS has experienced. In the previous two sequences, IBS 3 failed to send its own. Coexistence signaling.

In the example shown in FIG. 5, the IBS 1 arbitrarily selects the super CSI 1 to transmit its own reservation signal, the IBS 2 arbitrarily selects the super CSI 4 to transmit its own reservation signal, and the IBS 3 arbitrarily selects the super CSI 2 to transmit itself. Reservation signal. During Super CSI 1, when IBS 1 sends its reservation signal, IBS2 and IBS3 can scan the current super CSI during work. The rate energy level takes the priority of IBS 1. Since the priority of IBS 1 is lower than their own priority, IBS 2/IBS 3 decides to continue transmitting its own reservation signal. During Super CSI 2, IBS 3 sends its own reservation signal. IBS2 and IBS 1 can obtain the priority of IBS3 by scanning the power energy level during the current super CSI.

After completing the power level sweep of 4 super CSIs, IBS 1, IBS 2 and IBS 3 if compare the priorities of other IBSs with their own priorities to decide whether to transmit coexistence signaling. Since IBS 3 has the highest priority, IBS 3 can obtain the opportunity to transmit its own coexistence signaling and become OBS through coordination with other OBSs. While IBS 1 and IBS 2 will suspend coexistence signaling in the subsequent 224 ICSI and their priority will increase by 1. In the next ICSI sequence, IBS 1 and IBS 2 will restart similar procedures to transmit coexistence signaling. .

FIG. 6 shows a schematic block diagram of an IBS base station according to an embodiment of the present invention. The figure shows three base stations 601, 602, 603, each belonging to a different wireless communication system. Taking one of the base stations IBS 603 as an example, the base station includes a time window selecting means 611, a priority comparing means 612, and a coexistence signaling transmitting control means 613. Preferably, the base station 603 further includes a reservation signal transmission control means 614.

The device 611 is configured to select a time window from a plurality of reserved time windows, for example, 4 super CSIs, for example, the time window selected in FIG. 5 exceeds CSI 2 (CX frames 9 - 16 ) to prepare to transmit a reservation signal, where The reservation signal includes the priority information of the base station 603; correspondingly, the corresponding devices of the other base stations 601, 602 also arbitrarily select a reserved time window, such as the super CSI 1 and the super CSI 4 in FIG. 5, we can also call them The first time window and the fourth reserved time window.

The device 612 is configured to obtain priority information included in a reservation signal of another base station (ie, the base station 601, 602 in this example), and compare the priority information of the base station 603 with the priorities of the other base stations 601, 602.

At the end of the total reservation time window, for example, at the end of the four super CSIs in FIG. 5, the device 613, in the case where the base station 603 has a priority greater than the priorities of the base stations 601, 602, The coexistence signaling message is transmitted in the subsequent coexistence signaling transmission period (ie, within CX frames 33 to 256).

Similarly, taking the base stations 601 and 602 as an example, since the priorities (0 and 1 respectively) are smaller than the priority of the device 603 at the end of the four super CSIs, in the subsequent coexistence signaling transmission period, Suspend or suspend the transmission of its own coexistence signaling message.

Apparatus 614 is configured to: within a time window selected by the 603 base station, if the priority of base station 603 is greater than the priority of other base stations (e.g., 601) that have been learned by power level sweeping, base station 603 transmits a reservation signal if the base station If the priority of 603 is less than the priority of these base stations (e.g., 601), the base station 603 suspends the transmission of the reservation signal and increases its priority accordingly. Such a setting can further avoid conflicting problems that may occur when the reservation signal is transmitted.

For those skilled in the art, only one possible functional configuration of the IBS base station is provided in FIG. The base station according to the embodiment of the present invention does not involve hardware improvement, and can be implemented on the basis of the existing base station by combining computer software.

Although the invention has been described in connection with the embodiments, the invention is not limited to any embodiments. The scope of the invention is defined by the claims, and includes various alternatives, modifications and equivalents. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

Rights request

A method for performing spectrum sharing between a base station and at least one other base station, wherein all base stations belong to different wireless communication systems, and the method includes:

a. the base station and the at least one other base station respectively select a time window from a plurality of reserved time windows to prepare to transmit a reservation signal and at least one other reservation signal, the reservation signal including priority information of the base station The at least one other reservation signal includes priority information of the at least one other base station;

b. the base station obtains priority information included in the at least one other reservation signal, and compares priorities included in the reservation signal and the at least one other reservation signal;

c. In a case where the priority included in the reservation signal is greater than a priority included in the at least one other reservation signal, the base station transmits coexistence in a coexistence signaling transmission period after the plurality of reserved time windows Signaling message; otherwise suspend transmission of the coexistence signaling message.

2. The method of claim 1, wherein step b further comprises the base station obtaining a priority of the at least one other base station by scanning a power level of a reserved time window selected by the at least one other base station.

The method according to claim 1 or 2, further comprising: transmitting, in a time window selected by the base station, if a priority of the base station is greater than a priority of the at least one other base station, The reservation signal is described.

The method according to claim 1 or 2, further comprising: in a time window selected by the base station, if the priority of the base station is less than the priority of the at least one other base station, the base station is suspended Sending the reservation signal.

5. Method according to claim 1 or 2, wherein the priority of the base station depends on the number of coexistence signaling messages that the base station has experienced.

6. The method of claim 1 or 2, wherein the priority of the base station is dependent on a specific communication requirement of the base station, the specific communication requirement including military, medical or emergency communication At least one of the requirements.

The method according to claim 1 or 2, wherein in step c, if the transmission of the coexistence signaling message is suspended, the priority of the base station is increased by one.

A base station of a wireless communication system, the base station performing spectrum sharing with at least one other base station belonging to another wireless communication system, the base station comprising:

a time window selecting means for selecting a time window from a plurality of reserved time windows to prepare to transmit a reservation signal, wherein the reservation signal includes priority information of the base station;

a priority comparison device, configured to obtain priority information included in a reservation signal sent by the other base station, and compare a priority of the base station with a priority of the other base station;

a coexistence signaling transmission control apparatus, configured to: during a case where the priority included in the reservation signal is greater than a priority included in the other reservation signal, a coexistence signaling transmission period after the reserved time window The coexistence signaling message is sent, otherwise, the transmission of the coexistence signaling message is suspended.

9. The base station of claim 8, wherein the prioritization comparing means is further configured to obtain a priority of the other base station by scanning a power level of a reserved time window selected by the other base station.

10. The base station according to claim 8 or 9, further comprising a reservation signal transmission control device, the device being configured to: in a time window selected by the base station, if the level is, the base station transmits the reservation signal If the priority of the base station is less than the priority of the other base station, the base station suspends transmitting the reservation signal and increases its priority accordingly.

The base station according to claim 8 or 9, wherein the priority of the base station depends on the number of coexistence signaling messages that the base station has experienced, or depends on a specific communication requirement of the base station, the specific communication requirement Including military, medical or emergency communications requirements At least one of them.

12. A computer program product storing computer instructions for performing the steps of any of claims 1-7.