Power control technology used in microwave backhaul systems

Abstract

A power control device is used to control the transmission power of a microwave backhaul network of a microwave backhaul system including multiple microwave backhaul networks. For the microwave backhaul network, the power control device obtains information about the channel state of the corresponding microwave link in a specific number of time slots for each of the multiple microwave links of the microwave backhaul network; for each microwave link, based on the information about the channel state of each microwave link, determines the throughput on the corresponding microwave link in the specific number of time slots, and determines time information indicating that the throughput on the corresponding microwave link is higher than a link-specific threshold; for each microwave link, after determining that the time information for at least one microwave link is lower than a given threshold, determines the transmission power in each time slot.

Description

Technical Field

[0001] The present invention relates to a power control technology used in a microwave backhaul system, and in particular to an adaptive power control technology used in a microwave backhaul network. Background Art

[0002] In a conventional microwave backhaul network 100 that provides connectivity to a macro cell base station, a star topology is implemented as follows: Figure 1 As shown. A plurality of leaf nodes 101, 102, 103, 104 are connected to a hub node 110 via corresponding links 111, 112, 113, 114. This microwave backhaul network 100 is managed in the following manner: if the angular spacing α of the link pair j and k jk 121 is lower than the given threshold angle α Th , then orthogonal frequency channels are allocated to the link pair j and k; if the angular spacing α of the link pair j and k jk 121 is higher than the threshold angle α Th , then the same frequency channel is allocated to the link pair j and k. Threshold angle α Th It usually depends on: the radiation pattern (or interference suppression capability) of the antennas installed on the leaf nodes 101, 102, 103, 104 and the hub node 110; and the target available throughput guaranteed on different links 111, 112, 113, 114 (an exemplary throughput requirement for a microwave backhaul link may be 1 Gbit / s with an availability of 99.9% and 250 Mbit / s with an availability of 99.995%).

[0003] In most of the currently operating microwave backhaul systems that provide backhaul information transmission between macrocell base stations, the transmit power on any jth link in time slot λ is selected only As the channel state CS associated with the jth link at time slot λ j (λ), such as Figure 2 The microwave backhaul network 200 shown in FIG. Figure 2 In the star-based deployment drawn in FIG, hereinafter, the power transmitted from any j-th leaf node will be referred to as the j-th uplink transmission power 221, 222, 223, 224, and the power transmitted from the hub node to any j-th leaf node will be referred to as the j-th downlink transmission power ( Figure 2 not shown).

[0004] When using Figure 2 When the microwave backhaul network 200 is shown, the following limitations occur:

[0005] Limitation (1) The transmit power selected for use on a given link does not take into account the interference that may be generated on all other links of the network. Using prior art transmit power management strategies can result in higher interference levels on some network links, thereby limiting the threshold angle α between adjacent links sharing the same frequency channel. Th The requirements become more stringent (α Th The immediate disadvantage of this is that if α Th As it increases, the area spectral efficiency will decrease.

[0006] Limitation (2) The transmit power selected for use on a given link at a given time slot λ depends only on the channel state at time slot λ, without taking into account the channel state over a wider time span, which has a significant impact in determining the available throughput that can be guaranteed on the link. Therefore, selecting transmit power according to the transmit power management strategy of the prior art does not optimize the available throughput that can be guaranteed on different links. Therefore, the threshold angle α Th The value of is not optimized (it should be noted that the threshold angle α Th plays a key role in determining the available throughput that can be guaranteed on different links), which can lead to a decrease in area spectral efficiency. Summary of the invention

[0007] An object of the present invention is to provide a technology for solving the above-mentioned problems of a microwave backhaul network, namely, to improve the throughput of a microwave backhaul system (specifically, a microwave backhaul system including a plurality of microwave backhaul networks).

[0008] The above objects are achieved by the features of the independent claims. Other implementations are apparent from the dependent claims, the description and the drawings.

[0009] According to a first aspect, the present invention relates to a power control device for controlling the transmission power of at least one microwave backhaul network of a microwave backhaul system comprising a plurality of microwave backhaul networks, wherein the power control device is used to perform the following operations on the at least one microwave backhaul network: for each of a plurality of microwave links of the at least one microwave backhaul network, obtaining information about a channel state (CS) of the corresponding microwave link within a specific number (T) of time slots (t-α); n (t-α)); for each microwave link, based on the channel state (CS) of each microwave link of the at least one microwave backhaul network n (t–α)), determine the throughput (Th) on the corresponding microwave link within the specific number (T) of time slots (t–α) n (t–α)), and determine the throughput (Th n(t–α)) is above a given link-specific threshold (Th min ) time information (β n ); for each microwave link, in determining the time information (β n ) is lower than a given threshold (p min ) after which the transmission power of the corresponding microwave link in each time slot is determined.

[0010] This power control arrangement relaxes the requirement that for a fixed antenna pattern and target available throughput, the dynamic joint optimal selection of the uplink (and downlink) transmit power in each time slot reduces the required threshold angle α between adjacent links sharing the same frequency channel to Th Decrease. Decrease the threshold angle α Th This will improve the area spectrum efficiency.

[0011] In an exemplary implementation of the power control device, the channel state (CS) of the corresponding microwave link n The information about the channel state of each microwave link within the at least one microwave backhaul network itself and the information about the channel state of each interfering microwave link from or to another microwave backhaul network.

[0012] This provides a technical advantage in that the transmit power can be optimally adjusted even for a microwave backhaul system including a plurality of microwave backhaul networks, since interfering microwave links are included in the optimality criterion.

[0013] In an exemplary implementation of the power control device, the transmit power is determined by maximizing a minimum signal-to-interference-plus-noise ratio (SINR) associated with a common time slot and a common microwave link.

[0014] This provides a technical advantage of maximizing the result, so that the optimum transmit power is valid for a common time slot and a common microwave link.

[0015] In an exemplary implementation of the power control device, the transmit power is determined by maximizing the total throughput of the plurality of microwave links of the at least one microwave backhaul network within the specific number (T) of time slots under a constraint, wherein the constraint is that the transmission power is greater than or equal to the given threshold p for the time information. min , each microwave link provides a value greater than or equal to the given link-specific threshold Th min throughput.

[0016] This provides a technical advantage in meeting the requirements of microwave backhaul systems, which require a minimum throughput on a given link for a minimum percentage of the time.

[0017] In an exemplary implementation of the power control device, the transmit power is determined under the constraint to comply with a given transmit power dynamic range and / or a given output transmit power level of the microwave backhaul system.

[0018] This provides a technical advantage in that transmit power dynamic range and output level requirements can be met.

[0019] In an exemplary implementation of the power control device, the power control device is used to: adjust the microwave backhaul system to use the transmit power determined for each of the plurality of microwave links of the at least one microwave backhaul network.

[0020] This provides a technical advantage that the entire microwave backhaul system can be optimally designed and operated based on the determined optimal transmission power.

[0021] In an exemplary implementation of the power control device, the power control device is used to respectively determine the transmission power of each of the multiple microwave links of the at least one microwave backhaul network in two communication directions.

[0022] This provides a technical advantage in that a more precise adjustment of the transmit power can be achieved when the transmit power for two communication directions (eg uplink and downlink) is determined separately.

[0023] In an exemplary implementation of the power control device, the power control device is used to: for each microwave link, determine the transmit power of the corresponding microwave link time slot by time slot in an iterative manner; recalculate the throughput (Th) on the corresponding microwave link after each time slot iteration; n (t–α)) is above the given link-specific threshold (Th min ) of the time information (β n ).

[0024] This provides a technical advantage in that the processing complexity for solving the optimization problem is reduced when an iterative mechanism is used, since the entire algorithm can be distributed over various iterations. Furthermore, while the first iteration may yield a rough result, each further iteration may provide a more precise result.

[0025] In an exemplary implementation of the power control device, the power control device is used to: for each microwave link, based on the signal to interference plus noise ratio (SINR) of the corresponding microwave link in the corresponding time slot n(t–α)), determine the throughput Th on the corresponding microwave link within the specific number (T) of time slots n (t-α), wherein the signal to interference and noise ratio (SINR) of the corresponding microwave link at the corresponding time slot (t-α) is n (t-α)) is based on the channel state (CS) of each microwave link of the at least one microwave backhaul network at the corresponding time slot (t-α). n (t–α)).

[0026] This provides a technical advantage in that the computational complexity for calculating the throughput is reduced since the signal-to-interference-and-noise ratio is typically available for the power control device.

[0027] In an exemplary implementation of the power control device, the power control device is used to: for each microwave link, determine the signal-to-interference-plus-noise ratio (SINR) of the corresponding microwave link in the corresponding time slot (t-α) based on the following relationship: n (t–α)):

[0028]

[0029] Among them, θ n (t–α) represents the total attenuation occurring between the transmitting device of the nth microwave link and the receiving device of the nth microwave link in time slot t–α, P n (t–α) represents the transmission power used on the nth microwave link at time slot t–α, θ k (t–α) represents the total attenuation occurring between the universal kth transmitting device belonging to the microwave backhaul system and the receiving device of the nth microwave link at time slot t–α, γ n→n represents the total gain brought by the antenna radiation pattern of the transmitting device of the n-th microwave link and the antenna radiation pattern of the receiving device of the n-th microwave link, γ k→n represents the total gain brought by the antenna radiation pattern of the k-th transmitting device and the antenna radiation pattern of the receiving device of the n-th microwave link, P noise A measure of received noise power.

[0030] This provides a technical advantage in that the computational complexity for calculating the signal-to-interference-and-noise ratio is lower, since the signal-to-interference-and-noise ratio can be determined by simple multiplication and addition operations.

[0031] In an exemplary implementation of the power control device, the power control device is used to: create a channel status to optimal power (CS2P) table, the CS2P table including, for each microwave link and in each time slot, the channel status (CS2P) of the corresponding microwave link in the corresponding time slot. n (t–α)) and the associated optimal transmit power.

[0032] This provides a technical advantage that the CS2P table can be used to easily look up required information about the association between channel status and the optimal transmit power to be used in the microwave backhaul system. The CS2P table can be predetermined and pre-stored in the microwave backhaul system.

[0033] In an exemplary implementation of the power control device, the power control device is configured to: based on a predefined periodicity, use information about the channel state (CS n (t-α)) and the new information of the associated optimal transmit power update the CS2P table.

[0034] This provides a technical advantage in that changes in the microwave backhaul system (such as adding a new backhaul network or removing an existing backhaul network) can be easily mapped into the CS2P table.

[0035] In an exemplary implementation of the power control device, the power control device is used to: derive the channel state (CS) of the microwave link in the initialization phase from a memory accessible to the power control device. n (t–α)), wherein the memory stores information obtained from an available database including attenuation statistics for a given geographical area, or information obtained from existing standard recommendations, specifically ITU recommendations, or information obtained from information obtained before the microwave backhaul system is deployed in the field.

[0036] This provides a technical advantage in that delays are avoided in deriving the required channel state for a link in a microwave backhaul network within a specific number (T) of time slots, since this information is available from a memory.

[0037] In an exemplary implementation of the power control device, the power control device is located as a central entity in one of the microwave backhaul networks; or is distributed throughout the microwave backhaul system as a plurality of distributed entities.

[0038] This provides a technical advantage of high design flexibility. Depending on the actual requirements of the network element, the power control device can be implemented in any network element, for example, in a network element that provides necessary resources for the processing task of the power control device.

[0039] According to a second aspect, the present invention relates to a method for controlling the transmission power of at least one microwave backhaul network of a microwave backhaul system comprising a plurality of microwave backhaul networks, wherein the method comprises: for each microwave link of a plurality of microwave links of the at least one microwave backhaul network, obtaining information about a channel state (CS) of the corresponding microwave link within a specific number (T) of time slots (t-α); n (t-α)); for each microwave link, based on the channel state (CS) of each microwave link of the at least one microwave backhaul network n (t–α)), determine the throughput (Th) on the corresponding microwave link within the specific number (T) of time slots (t–α) n (t–α)), and determine the throughput (Th n (t–α)) is above a given link-specific threshold (Th min ) time information (β n ); for each microwave link, in determining the time information (β n ) is lower than a given threshold (p min ) after which the transmission power of the corresponding microwave link in each time slot is determined.

[0040] This method for controlling transmit power relaxes the requirement that for a fixed antenna pattern and target available throughput, the dynamic joint optimal selection of uplink (and downlink) transmit power in each time slot reduces the required threshold angle α between adjacent links sharing the same frequency channel to Th Decrease. Decrease the threshold angle α Th This will improve the area spectrum efficiency.

[0041] According to a third aspect, the present invention relates to a computer program product, the computer program product comprising computer executable code or computer executable instructions, which, when executed, cause at least one computer to perform a method according to the third aspect or the fourth aspect. Such a computer program product may include a non-transitory readable storage medium, the non-transitory readable storage medium having program code stored thereon for use by a processor, the program code comprising instructions for performing the method or calculation block described below.

[0042] The entity described in the present invention may include a processor for processing corresponding functions. The processor as described in the present invention may include hardware and software. The hardware may include digital circuits, or both analog circuits and digital circuits. The digital circuit may include components such as an application-specific integrated circuit (ASIC), a field-programmable array (FPGA), a digital signal processor (DSP) or a general-purpose processor. In one embodiment, the processor includes one or more processors and a non-transient memory connected to one or more processor cores. The non-transient memory may carry an executable program code, which, when executed by the one or more processor cores, causes the device to perform the operation or method described herein.

[0043] definition

[0044] In the following sections, the following terms, abbreviations, and symbols are used:

[0045] Backhaul Network:

[0046] In a layered telecommunications network, the backhaul portion of the network consists of the intermediate links between the core network or backbone and the smaller subnetworks at the edge of the network.

[0047] Angular spacing:

[0048] The angular separation or angular distance between two point objects is the angle between two directions originating from the observer and pointing toward the two objects, as viewed from a different position from either of these objects.

[0049] Time slot:

[0050] A time slot is defined as a universal, limited period of time.

[0051] Channel status:

[0052] The channel state CS associated with the jth link at time slot λ j (λ) is defined as an indication of the quality of the jth link in both the uplink (from the jth leaf node to the hub node) and downlink (from the hub node to the jth leaf node) directions within a time span of a given time slot λ. For example, but not limited to, the channel state may include a measure of the attenuation (in both directions) experienced on the jth wireless link during the time slot λ, and a measure of the interference level or interference pattern generated by other transmitting devices deployed in the microwave backhaul system. The channel state may also include the antenna gain on the jth link.

[0053] CS: Channel Status

[0054] CS2P: Channel Status and Power (Table) BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Other embodiments of the present invention will be described in conjunction with the following drawings.

[0056] Figure 1 A schematic diagram of a microwave backhaul network 100 is shown;

[0057] Figure 2 A schematic diagram of a microwave backhaul network 200 for uplink direction is shown;

[0058] Figure 3a A schematic diagram of a microwave backhaul network 300 and a power control device 310 for uplink direction provided by the present invention is shown;

[0059] Figure 3b An example of a channel status to optimal power (CS2P) table 300b provided by the present invention is shown;

[0060] Figure 4a An exemplary histogram 401 showing throughput on a first link of a microwave backhaul network;

[0061] Figure 4b An exemplary histogram 402 showing throughput on an Nth link of a microwave backhaul network;

[0062] Figure 5 A schematic diagram 500 showing the constrained maximization of the throughput function provided by the present invention;

[0063] Figure 6 A flow chart of a method 600 for controlling the transmission power of a microwave backhaul network provided by the present invention is shown;

[0064] Figure 7 A schematic diagram of a microwave backhaul system 700 including two microwave backhaul networks provided by the present invention is shown;

[0065] Figure 8 A schematic diagram of a network scenario 800 with two hub nodes and six leaf nodes provided by the present invention is shown;

[0066] Figures 9a to 9d Schematic diagrams of other random network scenarios 900a, 900b, 900c, and 900d with two hub nodes and six leaf nodes provided by the present invention are shown;

[0067] Fig.10 Performance diagram 1000 showing the performance of network scenarios with and without power control provided by the present invention;

[0068] Fig.11 A schematic diagram of a method 1100 for controlling the transmission power of a microwave backhaul system provided by the present invention is shown. DETAILED DESCRIPTION

[0069] The scheme according to the disclosure described below and in the Summary of the Invention section introduces a new adaptive power control scheme for microwave backhaul networks, which selects the jth uplink (and downlink) transmit power P at each jth time slot λ. j (λ) is the channel state CS associated with all links (n=1, 2, ..., N) of the network measured within a specific time span of T time slots (α=0, 1, 2, ..., T-1) n (t–α), where the specific time span of T time slots does not necessarily include time slot λ (see Figure 3 below).

[0070] This scheme is adaptive because the transmit power P used on N links 1 (λ),P 2 (λ),…,P N (λ) can change in each time slot λ. Select the transmission power P in each time slot λ. 1 (λ),P 2 (λ),…,P N (λ), the goal is to maximize the total throughput of the N links under the constraint of guaranteeing the available throughput required by each of the N links (this is a typical requirement for microwave backhaul systems).

[0071] The benefit of this scheme is that the requirement is relaxed: for a fixed antenna pattern and target available throughput, the uplink (and downlink) transmit power P in each time slot λ 1 (λ),P 2 (λ),…,P N The dynamic joint optimal selection of (λ) makes the required threshold angle α between adjacent links sharing the same frequency channel Th Decrease. Decrease the threshold angle α Th This will improve the area spectrum efficiency.

[0072] The disclosed solution provides an adaptive power control mechanism for a microwave backhaul network, including the following five operations:

[0073] (1) Initial data collection

[0074] (2) Data Analysis

[0075] (3) Transmit power optimization procedure

[0076] (4) Dynamic Transmit Power Control

[0077] (5) Update and optimize transmission power allocation

[0078] These five operations will be described in detail in the following sections of the present invention. Figure 6 as shown (for steps 1 to 4).

[0079] In the following detailed description, reference is made to the accompanying drawings which form a part of this specification, wherein specific aspects of the invention which may be practiced are illustrated by way of illustration. It is to be understood that other aspects may be utilized and structural or logical changes may be made without departing from the scope of the invention. Therefore, the following detailed description should not be understood in a restrictive sense, and the scope of the invention is defined by the appended claims.

[0080] It is understood that comments related to the described method are also applicable to the corresponding device or system for performing the method, and vice versa. For example, if a specific method step is described, the corresponding device may include a unit to perform the described method step, even if such a unit is not explicitly described or shown in the drawings. In addition, it is understood that the features of the various exemplary aspects described herein may be combined with each other unless otherwise explicitly stated.

[0081] The device may include integrated circuits and / or passive circuits and may be manufactured according to various technologies. For example, the circuit may be designed as a logic integrated circuit, an analog integrated circuit, a mixed signal integrated circuit, an optical circuit, a memory circuit and / or an integrated passive circuit.

[0082] The devices and systems described herein may include a processor or processing device or processing circuit, a memory and a transceiver, i.e., a transmitter and / or a receiver. In the following description, the term "processor" or "processing device" describes any device that can be used to process a specific task (or block or step). The processor or processing device may be a single-core processor or a multi-core processor, or may include a group of processors, or may include a processing module. The processor or processing device may process software, firmware, or applications, etc.

[0083] Figure 1 Schematic diagram of a microwave backhaul network 100 is shown. This conventional microwave backhaul network 100 provides connections to macrocell base stations. A plurality of leaf nodes 101, 102, 103, 104 are connected to a hub node 110 in a star topology via corresponding links 111, 112, 113, 114. As described above, such a microwave backhaul network 100 is managed as follows: if the angular spacing α of link pairs j and k is jk121 is lower than the given threshold angle α Th , then orthogonal frequency channels are allocated to the link pair j and k; if the angular spacing α of the link pair j and k jk 121 is higher than the threshold angle α Th , then the same frequency channel is allocated to the link pair j and k. Threshold angle α Th It usually depends on: the radiation pattern (or interference suppression capability) of the antennas installed on the leaf nodes 101, 102, 103, 104 and the hub node 110; and the target available throughput guaranteed on different links 111, 112, 113, 114 (an exemplary throughput requirement for a microwave backhaul link may be 1 Gbit / s with an availability of 99.9% and 250 Mbit / s with an availability of 99.995%).

[0084] Figure 2 FIG. 2 shows a schematic diagram of a microwave backhaul network 200 for uplink direction. Figure 1 The microwave backhaul network 100 shown is the same. A plurality of leaf nodes 101, 102, 103, 104 are connected to a hub node 110 via corresponding links 111, 112, 113, 114 in a star topology. Figure 2 The uplink case considering the uplink transmit power is described.

[0085] The transmit power on any jth link in time slot λ is chosen only As the channel state CS associated with the j-th link 221, 222, 223, 224 at time slot λ j (λ). The power transmitted from any j-th leaf node is represented as the j-th uplink transmission power. It should be noted that in the downlink direction ( Figure 2 (not shown in the figure), the power transmitted from the hub node to any j-th leaf node will be referred to as the j-th downlink transmission power. Therefore, the microwave backhaul network 200 is subject to the limitations as described above.

[0086] Figure 3a FIG. 3 is a schematic diagram of a microwave backhaul network 300 and a power control device 310 for uplink direction provided by the present invention. Figure 1 and Figure 2 The microwave backhaul networks 100, 200 shown are identical. A plurality of leaf nodes 101, 102, 103, 104 are connected to a hub node 110 in a star topology via corresponding links 111, 112, 113, 114. Fig. 3 depicts the uplink situation taking into account the uplink transmission power.

[0087] The power control device 310 is used to control the transmission power 320 of the microwave backhaul network 300. The power control device 310 can be used to control the transmission power 320 of a single microwave backhaul network 300, such as Figure 3a In addition, the power control device 310 can be used to control the transmission power of at least one microwave backhaul network of a microwave backhaul system including multiple microwave backhaul networks, for example Figure 7 As shown in the network scenario of Figure 9.

[0088] The power control device 310 is used to control at least one microwave backhaul network (eg Figure 3a The network 300 shown in FIG. 1 performs the following steps: (1) for each of the plurality of microwave links 111, 112, 113, 114 of at least one microwave backhaul network 300, obtain a channel state CS of the corresponding microwave link within a specific number T of time slots t-α; n (t-α); (2) for each microwave link 111, 112, 113, 114, based on the channel state CS of each microwave link 111, 112, 113, 114 of at least one microwave backhaul network 300 n (t–α), determine the throughput Th on the corresponding microwave link within a specific number T of time slots t–α n (t–α), and determine the throughput Th on the corresponding microwave links 111, 112, 113, 114 n (t–α) is above a given link-specific threshold Th min Time information of β n (3) for each microwave link 111, 112, 113, 114, after determining the time information β for at least one microwave link 111, 112, 113, 114 n Below a given threshold p min Afterwards, the transmit power of the corresponding microwave link 111, 112, 113, 114 in each time slot is determined 320. These steps will be described in more detail in the following sections.

[0089] Channel status CS of corresponding microwave links 111, 112, 113, 114 n The information of (t-α) may depend on information about the channel state of each microwave link 111, 112, 113, 114 within the at least one microwave backhaul network 300 itself, and information about the channel state of each interfering microwave link from or to another microwave backhaul network 801, such as Figure 8 as shown in .

[0090] The transmit power 320 may be determined by maximizing a minimum signal to interference plus noise ratio (SINR) associated with a common time slot and a common microwave link, for example as described below.

[0091] The transmit power 320 may be determined by maximizing 501 the total throughput of the plurality of microwave links 111, 112, 113, 114 of the at least one microwave backhaul network 300 within a certain number of time slots D ≤ T under the constraint 502 that the throughput is greater than or equal to a given threshold p for the time information. min , each microwave link 111, 112, 113, 114 provides a value greater than or equal to a given link-specific threshold Th min The throughput is as follows: Figure 5 described.

[0092] The transmit power 320 may be determined under constraints to comply with a given transmit power dynamic range and / or a given output transmit power level of the microwave backhaul system 800 .

[0093] The power control device 310 may be used to adjust the microwave backhaul system 800 to use a transmit power 320 determined for each of the plurality of microwave links 111 , 112 , 113 , 114 of the at least one microwave backhaul network 300 .

[0094] The power control device 310 may be used to respectively determine the transmission power 320 of each microwave link in two communication directions of a plurality of microwave links 111 , 112 , 113 , 114 of at least one microwave backhaul network 300 .

[0095] The power control device 310 may be used to: for each microwave link, determine the transmission power 320 of the corresponding microwave link in an iterative manner time slot by time slot; recalculate the throughput Th on the corresponding microwave link after each time slot iteration. n (t–α) is above a given link-specific threshold Th min Time information of β n , for example as described below.

[0096] The power control device 310 may be configured to: for each microwave link 111, 112, 113, 114, based on the signal to interference plus noise ratio SINR of the corresponding microwave link in the corresponding time slot n (t–α), determine the throughput Th on the corresponding microwave link within a specific number T of time slots n (t–α), where SINR is the signal-to-interference-plus-noise ratio (SINR) of the corresponding microwave link at the corresponding time slot t–α. n(t-α) is based on the channel state CS of each microwave link 111, 112, 113, 114 of at least one microwave backhaul network 300 at the corresponding time slot t-α. n (t–α) information.

[0097] The power control device 310 may be configured to: for each microwave link 111, 112, 113, 114, determine the signal to interference plus noise ratio SINR of the corresponding microwave link at the corresponding time slot t-α based on the following relationship: n (t–α):

[0098]

[0099] Among them, θ n (t–α) represents the total attenuation occurring between the transmitting device of the nth microwave link and the receiving device of the nth microwave link in time slot t–α, P n (t–α) represents the transmit power used on the nth microwave link in time slot t–α, θ k (t–α) represents the total attenuation occurring between the universal kth transmitting device and the nth receiving device of the microwave backhaul system in time slot t–α, γ n→n represents the total gain brought by the antenna radiation pattern of the transmitting device of the nth microwave link and the antenna radiation pattern of the receiving device of the nth microwave link, γ k→n P represents the total gain brought by the antenna radiation pattern of the kth transmitting device and the antenna radiation pattern of the nth receiving device of the microwave link. noise A measure representing received noise power, such as described below.

[0100] The power control device 310 can be used to: create a channel status to optimal power (CS2P) table, the CS2P table including channel status CS2P information about each microwave link 111, 112, 113, 114 and the corresponding microwave link in each time slot. n (t–α) and the associated transmit power 320 .

[0101] The power control device 310 may be configured to: based on a predefined periodicity, use the information about the channel status CS n The CS2P table is updated with the new information of (t–α) and the associated transmit power.

[0102] The power control device 310 may be configured to: derive the channel state CS of the microwave links 111, 112, 113, 114 in the initialization phase from a memory accessible to the power control device 310 n(t–α), for example as described below, wherein the memory stores information obtained from an available database including attenuation statistics for a given geographic area, or information obtained from existing standard recommendations, specifically ITU recommendations, or information obtained from information obtained before the microwave backhaul system 800 is deployed in the field.

[0103] The power control device 310 may be located in one of the microwave backhaul networks 300, 801 as a central entity (e.g., in the hub node 110); or distributed throughout the microwave backhaul system 800 as multiple distributed entities (e.g., in the leaf nodes 111, 112, 113, 114), for example, as described below with reference to Figure 8 shown.

[0104] Thus, the power control device 310 represents an apparatus for executing the disclosed scheme (i.e., an adaptive power control scheme for microwave backhaul networks), including five main operations: (1) initial data acquisition; (2) data analysis; (3) transmit power optimization procedure; (4) dynamic transmit power control; (5) updating the optimal transmit power allocation. These five operations will be described in detail in the following parts of the present invention. In terms of the steps of the method, the flowchart of the proposed scheme is as follows Figure 6 as shown (for steps 1 to 4).

[0105] First Operation: Initial Data Collection

[0106] The hub node 110 may be equipped with a control unit, namely Figure 3a The power control device 310 described in the embodiment is used to obtain information about uplink and downlink channel states CS of links 111, 112, 113, 114 (n=1, 2, ..., N) configured to provide a backhaul connection over a time span of T time slots (α=0, 1, 2, ..., T-1). n The control unit may be implemented in a centralized manner (eg, located only at the hub node 110 ) or in a distributed manner (distributed throughout the system).

[0107] According to one embodiment, during the initialization phase, information about the uplink and downlink channel states is available at the control unit. These pieces of information may be obtained from available databases (e.g., publicly accessible or proprietary databases) including attenuation statistics for a given geographical area or from existing ITU recommendations (e.g., ITU-R 530). Said initial information about the uplink and downlink channel states may be obtained before the device is deployed in the field and stored in a suitable memory support device connected to the control unit.

[0108] Alternatively, operations 1 to 3 may be performed offline and the result of the transmit power optimization procedure (i.e. the CS2P table as a result of the third operation, see below) may be stored directly in a suitable memory support device that may be connected to the control unit (as an initial transmit power allocation).

[0109] Channel Status CS n (t-α) may represent the attenuation experienced on the nth link in time slot t-α. The CS values ​​associated with the T time slots and N links (n=1, 2, ..., N, and α=0, 1, 2, ..., T-1) are obtained. n The information of (t–α) can be collected and stored in a suitable memory, and the time span of T time slots is large enough to properly characterize the statistical behavior of different link states.

[0110] Second operation: data analysis

[0111] According to the obtained measurement results, CS n (t–α) (n = 1, 2, 3, ..., N, and α = 0, 1, 2, ..., T–1) and the transmit power level P used on each nth link in each time slot t–α n (t–α), the control unit can calculate the signal-to-interference-plus-noise ratio SINR experienced on each nth link in each time slot t–α (n=1, 2, 3, …, N, and α=0, 1, 2, …, T–1) n (t–α). This can be defined as

[0112]

[0113] Among them, θ n (t–α) represents the total attenuation occurring between the transmitting device of the nth microwave link and the receiving device of the nth microwave link at time slot t–α, P n (t–α) represents the transmission power used on the nth microwave link at time slot t–α, θ k (t–α) represents the total attenuation occurring between the universal kth transmitting device belonging to the microwave backhaul system and the receiving device of the nth microwave link at time slot t–α, γ n→n represents the total gain brought by the antenna radiation pattern of the transmitting device of the n-th microwave link and the antenna radiation pattern of the receiving device of the n-th microwave link, γ k→n represents the total gain brought by the antenna radiation pattern of the k-th transmitting device and the antenna radiation pattern of the receiving device of the n-th microwave link, P noise A measure of received noise power.

[0114] In one implementation, the initial uplink transmit power may be set by a control unit (e.g., in the hub node 110) and may be communicated to the leaf nodes 101, 102, 103, 104 via an appropriate dedicated control channel. In an alternative implementation, the initial uplink transmit power may be independently selected by each leaf node 101, 102, 103, 104, and each leaf node may then communicate the value of its initial uplink transmit power to the control unit via an appropriate dedicated control channel.

[0115] The control unit may use the derived set of SINRs to derive a corresponding set of throughputs supported over N links and in T time slots as follows:

[0116] Th n (t–α)=BW×ω(SINR n (t–α)

[0117] for uplink and downlink (α = 0, 1, 2, ..., T–1, and n = 1, 2, 3, ..., N), where BW is the system bandwidth and ω() is a convenient function that maps SINR to the corresponding spectral efficiency measured in [bit / s / Hz] (for example, it can be the well-known Shannon formula defined as ω(x) = log 2 (1+x)).

[0118] Microwave backhaul systems usually require a minimum throughput Th on a given link. min , minimum duration percentage p min For example, it may be required that each link in a given microwave backhaul network experience a power greater than or equal to Th 99.995% of the time. min = 250Mbit / s throughput (in this case, p min =0.99995).

[0119] To verify that these requirements for the throughput available to each link are met, the control unit may then calculate the throughput delivered on each nth link (over a time span of T time slots) Th n The control unit can estimate the backhaul throughput delivered on each nth link to maintain the minimum throughput Th min Percentage of time above β n , as shown below:

[0120]

[0121] Among them, t n Indicates that the throughput experienced on the nth link is greater than or equal to the threshold Th min The amount of time (see below Figure 4a / Figure 4b )。

[0122] If all link percentages β 1 , β 2 , β 3 , ……, β N are all higher than p min , then no further operation is required. If β 1 , β 2 , β 3 , ……, β N in at least one of the link percentages is lower than p min , then the transmit power optimization program is executed. The transmit power optimization program is described in detail in the following operation (the third operation or step 3).

[0123] The third operation: transmit power optimization procedure

[0124] The control unit can first identify a subset D = {δ 1 , δ 2 , …, δ D} (D < T) of T time slots, where at least one of the throughputs experienced on N links is lower than Th min . Expressed in mathematical notation as:

[0125] D = {x ∈ {t, t–1, t–2, … t–T+1}|Th 1 (x) < Th min ∪ Th 2 (x) < Th min ∪ … ∪ Th N (x) < Th min}

[0126] Then, the control unit can select the transmit power values P i ∈ D (i = 1, 2, ……, D) to be used on N links 111, 112, 113, 114 in each time slot δ 1 (δ i ), P 2 (δ i ), …, P N (δ i ) to maximize the total throughput of the N links within the D time slots, while ensuring that each nth link provides a throughput greater than or equal to Th within the time percentage min . It should be noted that the time percentage on each nth link and the system throughput depend on the new transmit power allocation. Figure 5This dependency is further outlined and an optimization scheme is shown in mathematical notation. min The total throughput over the N links 111, 112, 113, 114 within the D time slots is maximized 501 under the constraint 502 of the minimum available throughput on each link 111, 112, 113, 114 within the time percentage.

[0127] Figure 5 The optimization problem shown in is complex due to the non-convexity of the optimization.

[0128] Different heuristics can be used to find a convenient transmit power allocation strategy that can meet the target throughput requirement.

[0129] An exemplary low complexity method for finding the optimal transmit power is described by the following pseudo code.

[0130] – Calculate the initial link percentage β 1 , β 2 , β 3 , ..., β N

[0131] – Select the current time slot δ i =δ 1

[0132] – When β 1 , β 2 , β 3 , ..., β N At least one link percentage is lower than p min hour,

[0133] (1) By solving the time slot δ i The related maximization minimum SINR optimization problem P1 (described below) is used to select the transmit power P 1 (δ i ),P 2 (δ i ),…,P N (δ i )

[0134] (2) Use the data analysis program to recalculate the link percentage β n (n=1, ..., N) (see step 2 above)

[0135] (3)δ i =δ i+1

[0136] Finish

[0137] With universal time slot δ iThe related optimization problem P1 of maximizing the minimum SINR is formulated as maximizing i Minimum SINR transmission power P of microwave backhaul network 1 (δ i ),P 2 (δ i ),…,P N (δ i ). In mathematical notation it is:

[0138]

[0139] Among them, in a given time slot δ i Signal to Interference and Noise Ratio SINR n (δ i )(n=1, 2, ..., N) are predefined.

[0140] The throughput maximization problem can be further constrained to comply with the available transmit power dynamic range or available output transmit power level of the system. i The N optimized transmission power values ​​320 (i=1, 2, ..., D) are related to the time slot δ i The measured N channel status sets are associated to generate a channel status to optimal power (CS2P) table, such as Figure 3b as shown in .

[0141] like Figure 3b As shown in , the size of the channel statuses to optimal power (CS2P) table can be Dx2NxW bytes, where W is the size of a binary string required to represent each entry of the CS2P table, in bytes, as described above, N is the number of links, D is the number of time slots, and at least one of the throughputs experienced on the N links is less than Th min .

[0142] In one exemplary implementation with the following typical values:

[0143] –T=10 8 time slots,

[0144] –D=T / 10 4 =10 4 time slots (for example, for p min =0.9999),

[0145] – N = 30 links (for dense scenarios),

[0146] –W = 2 bytes,

[0147] The CS2P table will occupy 1.2 megabytes in size.

[0148] Fourth operation: dynamic transmit power control

[0149] During subsequent system operation, at a given time slot λ, if the channel states CS measured on N links (n=1, 2, ..., N) n (λ) is equal to the combination of channel states in the kth row of the CS2P table, and the predefined tolerance is ε, the control unit can configure the microwave backhaul system to use the combination of transmit powers specified at the kth row of the CS2P table.

[0150] For example, if

[0151] CS 1 (δ 14 )-ε≤CS 1 (λ)≤CS 1 (δ 14 )+ε

[0152] CS 2 (δ 14 )-ε≤CS 2 (λ)≤CS 2 (δ 14 )+ε

[0153]

[0154] CS N (δ 14 )-ε≤CS N (λ)≤CS N (δ 14 )+ε

[0155] Then the transmission power P should be used on N links in time slot λ 1 (δ 14 ), P 2 (δ 14 ), ..., P N (δ 14 ).

[0156] Conversely, if no match is found between the N measured channel conditions at time slot λ and the combinations listed in the CS2P table, then predefined default values ​​for the N transmit powers may be applied.

[0157] In case of uplink transmission, the optimal uplink transmit power value to be used may be communicated to each leaf node 101, 102, 103, 104 via a dedicated control channel.

[0158] Fifth operation: Update and optimize transmission power allocation

[0159] The hub node 110 may be equipped with a control unit (ie, Figure 3a The power control device 310 shown in FIG. 1 is used to periodically measure the uplink and downlink channel states CS of links 111, 112, 113, 114 (n=1, 2, ..., N) configured to provide a backhaul connection over a time span of T time slots (α=0, 1, 2, ..., T-1). n (t-α).

[0160] Regarding the CS associated with the T time slots and N links (n=1, 2, ..., N, and α=0, 1, 2, ..., T-1) n The measurement results of (t-α) can be collected and stored in a suitable memory, and the time span of T time slots is large enough to properly characterize the statistical behavior of different link states.

[0161] The set of measurement results can be used according to the same procedure described above (operation 1 to operation 3 or steps 1 to step 3, respectively) to update the transmit power value and channel state value in the CS2P table. The step of updating the optimal transmit power allocation can be performed with a predefined periodicity. In the case of a newly added leaf node, the CS2P table can be recalculated according to the disclosed scheme.

[0162] Figure 4a and Figure 4b Exemplary histograms 401 , 402 of throughput on a first link and an Nth link of a microwave backhaul network are shown.

[0163] As mentioned above Figure 3a The described power control device 310 can calculate the throughput Th on each nth link (over a time span of T time slots) n The power control device 310 can estimate the backhaul throughput delivered on each nth link to maintain the minimum throughput Th min Percentage of time above β n , as shown below:

[0164]

[0165] Among them, t n Indicates that the throughput experienced on the nth link is greater than or equal to the threshold Th min The amount of time ( Figure 4a It shows that 1 For example, Figure 4b It shows that Nfor example).

[0166] If all link percentage β 1 , β 2 , β 3 ,......,β N All higher than p min , no further action is required. 1 , β 2 , β 3 ,......,β N At least one link percentage is lower than p min , then execute the transmit power optimization procedure, for example according to the above reference Figure 3a Description.

[0167] Figure 5 A schematic diagram 500 is shown showing the maximization of the throughput function provided by the present invention.

[0168] Figure 3a The power control device 310 shown in FIG. 3 can select to i ∈ D (i = 1, 2, ..., D) to be used on the N links 111, 112, 113, 114 1 (δ i ), P 2 (δ i ), ..., P N (δ i ) to maximize the total throughput of the N links in the D time slots while ensuring that each nth link is Provided within greater than or equal to Th min It should be noted that the percentage of time on each nth link and system throughput Depends on the new transmit power allocation. Figure 5 This dependency is shown in Figure 2, and the optimization scheme is described in mathematical notation. min The total throughput over the N links 111, 112, 113, 114 within the D time slots is maximized 501 under the constraint 502 of the minimum available throughput on each link 111, 112, 113, 114 within the time percentage.

[0169] Figure 5 The optimization problem shown in is complex due to the non-convexity of the optimization.

[0170] Different heuristics can be used to find a convenient transmit power allocation strategy that can meet the target throughput requirements. Figure 3aAn exemplary allocation strategy is described.

[0171] Figure 6 A flow chart of a method 600 for controlling the transmission power of a microwave backhaul network provided by the present invention is shown.

[0172] Method 600 represents the first four operations of the disclosed scheme, for example, according to the description above with reference to FIG3. The first operation "initial data acquisition" includes step 601. The second operation "data analysis" includes step 602, step 603 and step 604. The third operation "transmit power optimization procedure" includes step 605. The fourth operation "dynamic transmit power control" includes step 606, step 607, step 608 and step 609.

[0173] The method 600 starts from step 601: "Obtain CS of N links (n=1, 2, ..., N) within a time span of T time slots (α=0, 1, 2, ..., T-1) n (t–α)”. Step 602 is as follows: “Estimate the throughput on N links in T time slots”. Step 603 is as follows: “Estimate the throughput of each nth link above the threshold Th min The percentage of time β n If in step 604, for all N links (n=1, 2, ..., N), β n ≥p min If true, the method 600 jumps to step 606, otherwise, it executes step 605: "Solve the constraint throughput maximization problem (see Figure 5 ), and establish a table (CS2P table) that associates the combination of channel states on N links with the combination of optimal transmission powers on N links. Step 606 is as follows: "During subsequent system operation, measure the channel state CS at each time slot λ (n=1, 2, ..., N) n (λ)". If in step 607, the channel state measured in time slot λ appears in the CS2P table, go to step 608: "Use the N best transmit powers corresponding to time slot λ as indicated in the CS2P table". Otherwise, go to step 609: "Apply the predefined default values ​​of N transmit powers in time slot λ".

[0174] Figure 7 A schematic diagram of a microwave backhaul system 700 provided by the present invention including two microwave backhaul networks is shown.

[0175] Reference above Figure 3a The described solution can also be applied to a microwave backhaul system 700 including two microwave backhaul networks, such as Figure 7The microwave backhaul system 700 includes two exemplary number of star-type backhaul subsystems 711 and 712 operating on the same frequency channel, and each subsystem 711 and 712 includes a hub node 710 and 720 and a plurality of leaf nodes 701 , 702 , 703 , 704 and 705 .

[0176] According to the disclosed adaptive power control scheme for microwave backhaul networks, uplink and downlink transmit powers on each link measured within an appropriate time span may be selected according to the same process described above utilizing knowledge of the uplink and downlink channel states of all network links.

[0177] Figure 8 A schematic diagram of a network scenario 800 provided by the present invention is shown, which has two hub nodes 110, 820 and six leaf nodes 101, 102, 103, 104, 805, 806.

[0178] The network scenario 800 represents a microwave backhaul system 800 including two microwave backhaul networks, such as the first microwave backhaul network 300 according to the description above with reference to Figure 3 and the second microwave backhaul network 801 including a hub node 820 and two leaf nodes 805, 806. Each of the star backhaul subsystems 300, 801 can operate on the same frequency channel.

[0179] right Figure 8 The specific network scenario shown was numerically simulated. The adaptive power control method using the disclosed microwave backhaul network is able to achieve the target performance on all wireless links (for 99.5% of the time, the throughput is greater than 3.5Gbit / s, for 99.995% of the time, the throughput is greater than 500Mbit / s). The transmit power management of the prior art will only guarantee the target performance on 33% of the network links.

[0180] Figures 9a to 9d Schematic diagrams of other random network scenarios 900a, 900b, 900c, and 900d provided by the present invention with two hub nodes and six leaf nodes operating on the same frequency channel are shown.

[0181] Numerical simulations were performed on 50 network scenarios, such as Figures 9a to 9d As shown in , each scene is represented by 2 hub nodes and 6 leaf nodes. Figure 9b The network scenario of is a special case, where the first hub node 930 is connected to six leaf nodes, and the second hub node (not shown) has no leaf nodes. The performance of these network scenarios is as follows Fig.10Compared with the transmission power management method in the prior art, the use of the disclosed adaptive power control method for microwave backhaul networks can achieve a 15 dB gain 1009 in interference suppression capability at the hub node.

[0182] Fig.10 A performance graph 1000 showing the performance of network scenarios with and without power control provided by the present invention is shown. The X-axis depicts the interference suppression capability of the central hub site (in dB); the Y-axis depicts the percentage of links matching the target performance.

[0183] Performance graph 1000 shows that nearly 100% of the links match the target performance when the adaptive network power control 1001 provided by the present invention is applied. Specifically, at 99.5% availability, a throughput of greater than 3.5Gbit / s can be achieved, and at 99.995% availability, a throughput of greater than 500Mbit / s can be achieved. In contrast, it can be seen from the figure that without the adaptive network power control 1002 provided by the present invention, far fewer links match this target performance. For the interference suppression capability at the hub node, a gain of about 15dB can be achieved 1009.

[0184] When the adaptive network power control provided by the present invention is applied, the following benefits can be achieved: (i) the disclosed adaptive power control method effectively increases the number of co-channel links (i.e., links sharing the same frequency channel) by improving link availability; (ii) the disclosed adaptive power control method enables high gain (>10dB) in interference suppression of co-channel links at hub nodes.

[0185] Fig.11 A schematic diagram of a method 1100 for controlling the transmission power of a microwave backhaul system provided by the present invention is shown.

[0186] The method 1100 may be used to control the transmission power of at least one microwave backhaul network of a microwave backhaul system including a plurality of microwave backhaul networks, for example, as described above with reference to Figure 3a described.

[0187] The method 1100 includes: performing the following operations for at least one microwave backhaul network: for each microwave link of a plurality of microwave links of the at least one microwave backhaul network, obtaining 1101 a channel state CS of the corresponding microwave link within a specific number T of time slots t-α n (t–α) information, such as the above reference Figure 3a For each microwave link, based on the channel state CS of each microwave link of at least one microwave backhaul network n(t–α), determining 1102 the throughput Th on the corresponding microwave link within a specific number T of time slots t–α n (t–α), and determine the throughput Th on the corresponding microwave link n (t–α) is above a given link-specific threshold Th min Time information of β n , for example as referenced above Figure 3a For each microwave link, in determining the time information β for at least one microwave link n Below a given threshold p min Thereafter, determining 1103 the transmission power of the corresponding microwave link in each time slot, for example, as described above with reference to Figure 3a described.

[0188] The present invention also supports a computer program product comprising computer executable code or computer executable instructions, which when executed causes at least one computer to perform the processing and computing steps described herein, in particular the above-mentioned methods and procedures. This computer program product may include a readable non-transitory storage medium on which the program code is stored for use by a computer. The program code may perform the processing and computing steps described herein, in particular the above-mentioned methods and procedures.

[0189] Although specific features or aspects of the present invention may have been disclosed in conjunction with only one of several implementations, such features or aspects may be combined with one or more features or aspects in other implementations, as long as it is necessary or advantageous for any given or specific application. Moreover, to a certain extent, the terms "including", "having", "having" or other variations of these words are used in the detailed specification or claims, and such terms are similar to the term "including" and are both intended to include. Similarly, the terms "exemplarily" and "for example" are only represented as examples, rather than the best or optimal. The terms "coupled" and "connected" and derivatives may be used. It should be understood that these terms can be used to indicate that two elements cooperate or interact with each other, regardless of whether they are in direct physical contact or electrical contact, or they are not in direct contact with each other.

[0190] Although specific aspects have been illustrated and described herein, it will be appreciated by those skilled in the art that various alternative and / or equivalent implementations may be made to the specific aspects shown and described without departing from the scope of the invention. This application is intended to cover any modifications or variations of the specific aspects discussed herein.

[0191] Although the elements in the above claims are listed in a specific order with corresponding labels, these elements are not necessarily limited to being implemented in that specific order unless the claim recitation otherwise implies a specific order for implementing some or all of these elements.

[0192] Through the above enlightenment, it is obvious to those skilled in the art that many alternative products, modifications and variations are available. Of course, it is easy for those skilled in the art to realize that there are many other applications of the present invention in addition to the applications described herein. Although the present invention has been described with reference to one or more specific embodiments, it will be appreciated by those skilled in the art that many changes may be made to the present invention without departing from the scope of the present invention. Therefore, it should be understood that the present invention may be practiced in a manner different from that specifically described herein, as long as it is within the scope of the appended claims and their equivalents.

Claims

1. A power control device (310), characterized in that: Used to control the transmission power (320) of at least one microwave backhaul network (300) of a microwave backhaul system (800) comprising a plurality of microwave backhaul networks (300, 801), wherein the power control device (310) comprises a processor, and the processor is used to perform the following operations on the at least one microwave backhaul network (300): For each microwave link among a plurality of microwave links (111, 112, 113, 114) of the at least one microwave backhaul network (300), a channel state CS of the corresponding microwave link within a specific number T of time slots (t-α) is obtained. n (t-α); the n is a positive integer used to identify each microwave link in the multiple microwave links; For each microwave link (111, 112, 113, 114), based on the channel state CS of each microwave link (111, 112, 113, 114) of the at least one microwave backhaul network (300), n (t–α), determine the throughput Th on the corresponding microwave link within the specific number T of time slots (t–α) n (t-α), and determine the throughput Th on the corresponding microwave link (111, 112, 113, 114) n (t–α) is above a given link-specific threshold Th min The percentage of time β n ; The n The throughput experienced on the nth link is greater than or equal to the threshold Th min the amount of time; For each microwave link (111, 112, 113, 114), after determining the time information β for at least one microwave link (111, 112, 113, 114), n Below a given threshold p min Then, determining the transmission power (320) of the corresponding microwave links (111, 112, 113, 114) in each time slot; The transmit power (320) is determined by maximizing a minimum signal-to-interference-and-noise ratio (SINR) associated with a common time slot and a common microwave link; or, The transmit power (320) is determined by maximizing (501) the total throughput of the plurality of microwave links (111, 112, 113, 114) of the at least one microwave backhaul network (300) within the specific number T of time slots under the constraint (502), wherein the constraint is that the time information is greater than or equal to the given threshold p min , each microwave link (111, 112, 113, 114) provides a threshold value greater than or equal to the given link-specific threshold value Th min throughput.

2. The power control device (310) according to claim 1, characterized in that: The channel status CS of the corresponding microwave link (111, 112, 113, 114) n The information of (t-α) depends on the information about the channel state of each microwave link (111, 112, 113, 114) within the at least one microwave backhaul network (300) itself, and the information about the channel state of each interfering microwave link from or to another microwave backhaul network (801).

3. The power control device (310) according to claim 1 or 2, characterized in that: The transmit power (320) is determined under the constraints to comply with a given transmit power dynamic range and / or a given output transmit power level of the microwave backhaul system (800).

4. The power control device (310) according to any one of claims 1 or 2, characterized in that: The processor is further configured to: The microwave backhaul system (800) is adjusted to use the transmit power (320) determined for each of the plurality of microwave links (111, 112, 113, 114) of the at least one microwave backhaul network (300).

5. The power control device (310) according to any one of claims 1 or 2, characterized in that: The processor is further configured to: The transmission power (320) of each microwave link in the plurality of microwave links (111, 112, 113, 114) of the at least one microwave backhaul network (300) in two communication directions is determined respectively.

6. The power control device (310) according to any one of claims 1 or 2, characterized in that: The processor is further configured to: For each microwave link, determining the transmit power of the corresponding microwave link time slot by time slot in an iterative manner (320); After each time slot iteration, the throughput Th on the corresponding microwave link is recalculated. n (t–α) is above the given link-specific threshold Th min The time information β n .

7. The power control device (310) according to any one of claims 1 or 2, characterized in that: The processor is further configured to: For each microwave link (111, 112, 113, 114), based on the signal-to-interference-plus-noise ratio SINR of the corresponding microwave link in the corresponding time slot n (t-α), determine the throughput Th on the corresponding microwave link within the specific number T of time slots n (t–α), Wherein, the signal to interference plus noise ratio SINR of the corresponding microwave link at the corresponding time slot (t-α) is n (t-α) is based on the channel state CS of each microwave link (111, 112, 113, 114) of the at least one microwave backhaul network (300) at the corresponding time slot (t-α) n (t–α) information.

8. The power control device (310) according to claim 7, characterized in that: The processor is further configured to: For each microwave link (111, 112, 113, 114), the signal to interference plus noise ratio SINR of the corresponding microwave link at the corresponding time slot (t-α) is determined based on the following relationship: n (t–α): Among them, θ n (t–α) represents the total attenuation occurring between the transmitting device of the nth microwave link and the receiving device of the nth microwave link in time slot t–α, P n (t–α) represents the transmission power used on the nth microwave link at time slot t–α, θ k (t–α) represents the total attenuation occurring between the universal kth transmitting device belonging to the at least one microwave backhaul network and the receiving device of the nth microwave link at time slot t–α, γ n→n represents the total gain brought by the antenna radiation pattern of the transmitting device of the n-th microwave link and the antenna radiation pattern of the receiving device of the n-th microwave link, γ k→n represents the total gain brought by the antenna radiation pattern of the k-th transmitting device and the antenna radiation pattern of the receiving device of the n-th microwave link, P noise A measure of received noise power.

9. The power control device (310) according to any one of claims 1 or 2, characterized in that: The processor is further configured to: A channel state and optimal power CS2P table is created, wherein the CS2P table includes the channel state CS2P information about each microwave link (111, 112, 113, 114) and the channel state CS2P information about the corresponding microwave link in the corresponding time slot obtained in each time slot. n (t - α) and the associated transmit power (320).

10. The power control device (310) according to claim 9, characterized in that: The processor is further configured to: Based on a predefined periodicity, using information about the channel state CS n The CS2P table is updated with the new information of (t-α) and the associated transmit power.

11. The power control device (310) according to any one of claims 1 or 2, characterized in that: The processor is further configured to: The channel state CS of the microwave link (111, 112, 113, 114) in the initialization phase is derived from a memory accessible by the power control device (310). n (t–α) information, The memory stores information obtained from an available database including attenuation statistics for a given geographical area, or information obtained from existing standard recommendations, specifically ITU recommendations, or information obtained from information obtained before the microwave backhaul system (800) is deployed on site.

12. The power control device (310) according to any one of claims 1 or 2, characterized in that: as a central entity (110) located in one of the microwave backhaul networks (300, 801); or As multiple distributed entities (101, 102, 103, 104) distributed throughout the microwave backhaul system (800).

13. A method (1100) for controlling the transmission power of at least one microwave backhaul network of a microwave backhaul system comprising a plurality of microwave backhaul networks, characterized in that: The method comprises: performing the following operations on the at least one microwave backhaul network: For each microwave link of the plurality of microwave links of the at least one microwave backhaul network, obtaining (1101) a channel state CS of the corresponding microwave link within a specific number T of time slots (t-α) n (t-α); the n is a positive integer used to identify each microwave link in the multiple microwave links; For each microwave link, based on the channel state CS of each microwave link of the at least one microwave backhaul network n (t-α), determining (1102) the throughput Th on the corresponding microwave link in the specific number T of time slots (t-α) n (t-α), and determine the throughput Th on the corresponding microwave link n (t–α) is above a given link-specific threshold Th min The percentage of time β n ; The n The throughput experienced on the nth link is greater than or equal to the threshold Th min the amount of time; For each microwave link, after determining the time information β for at least one microwave link n Below a given threshold p min Thereafter, determining (1103) the transmission power of the corresponding microwave link in each time slot; The transmit power is determined by maximizing a minimum signal-to-interference-and-noise ratio SINR associated with a common time slot and a common microwave link; or, The transmit power is determined by maximizing the total throughput of the plurality of microwave links of the at least one microwave backhaul network within the specific number T of time slots under the constraint that the time information is greater than or equal to the given threshold p min , each microwave link provides a value greater than or equal to the given link-specific threshold Th min throughput.

Images