CN111525997B - Wireless broadband ad hoc network transmission method - Google Patents

Abstract

The invention discloses a transmission method of a wireless broadband ad hoc network, which provides a transmission scheme of the wireless broadband ad hoc network, and solves the problem of transmission interruption during remote communication by adjusting a physical time-frequency resource distribution mode and a service mode aiming at the conditions that the transmission distance between a transmitting end and a receiving end of the wireless broadband ad hoc network is gradually increased and the channel condition is gradually deteriorated under a mobile environment; the scheme of the invention increases the coverage of the sending node by changing the physical resource allocation mode and reduces the network deployment cost. Meanwhile, under the mobile environment, with the increase of the transmission distance, the uninterrupted service is realized by orderly reducing the service mode.

Description

Wireless broadband ad hoc network transmission method

Technical Field

The invention relates to the technical field of wireless communication, in particular to a wireless broadband ad hoc network transmission method.

Background

The wireless ad hoc network is a new wireless network architecture completely different from the traditional wireless cellular network, nodes in the network are all peer-to-peer, and each node can send and receive signals. Compared with the traditional cellular network, the wireless ad hoc network has the advantages of flexible and simple networking, high network reliability, large coverage range and the like. With the mature application of OFDM-MIMO (orthogonal frequency division multiple access and multiple input multiple output) technology and the rapid development of multimedia services, wireless broadband ad hoc networks are in demand. Since wireless ad hoc networks do not have a unified standard, communication between network nodes typically employs existing wireless communication protocols, such as LTE protocol, wiFi protocol, and the like.

For a wireless broadband ad hoc network based on TD-LTE technology, the frame structure is generally as shown in fig. 1. In the time domain, one radio frame includes ten subframes, each subframe includes two slots, each slot is 0.5ms in length, and each slot includes 7 OFDM symbols. In the frequency domain, the system operating bandwidth is usually 5 MHz/10 MHz/20MHz, and can be customized according to the requirement. The operating bandwidth is typically divided into a number of consecutive sub-carriers spaced apart by 15kHz, and the time-frequency resource elements are divided as shown in fig. 2. A Resource composed of 7 consecutive OFDM symbols in the time domain and 12 consecutive subcarriers in the frequency domain becomes a Physical Resource Block (PRB), and the number of PRBs in the frequency domain is related to the working bandwidth.

As shown in fig. 3, all frequency domain resources on the first three OFDM symbols in one subframe are used to carry control information, and the frequency domain resources on the remaining OFDM symbols are used to carry data blocks. The PRBs in the frequency domain are the smallest resource allocation units, one data block occupies one or more PRBs in the frequency domain, and multiple data blocks share the PRBs in the working bandwidth. The control information corresponding to the multiple data blocks shares physical resources on the first three OFDM symbols, and the control information is used to carry resource allocation information, modulation coding information, and the like of the corresponding data blocks. The receiving end usually blindly detects the control information first, so as to demodulate the corresponding data block according to the control information.

In a wireless broadband ad hoc network, an Adaptive Modulation and Coding (AMC) technique is generally used. The receiving end estimates the wireless Channel condition between the transmitting end and the receiving end according to the previous transmission, and usually adopts Channel Quality Indication (CQI) for measurement. The receiving end feeds back the CQI information to the transmitting end, the CQI is generally divided into 0 to 15 classes, and each class corresponds to a different modulation and coding scheme, as shown in fig. 4. And when the sending end carries out the next transmission, the corresponding modulation coding mode is selected according to the CQI grade, and the size of the data block is selected according to the CQI grade and the number of the allocated PRBs.

For different services, the higher the transmission rate requirement, the larger the data block per transmission. Under the condition that the wireless channel condition is fixed, the received signal level can be improved by improving the transmitting power, or the transmission code rate can be reduced by increasing the allocation of PRB resources. Considering that one transmitting end needs to transmit data to multiple receiving ends, the PRB resources allocated to the data block corresponding to each receiving end are also limited. In a mobile scene, the transmission distance between a wireless ad hoc network sending end and a wireless ad hoc network receiving end may gradually increase, the wireless channel condition gradually becomes worse, and the transmission performance during long-distance communication cannot be ensured by adopting the prior art.

Disclosure of Invention

In view of the above technical deficiencies, an object of the present invention is to provide a method for transmitting a wireless broadband ad hoc network, which solves the problem of transmission interruption during long-distance communication by adjusting a physical time-frequency resource allocation manner and a service mode in response to a situation that a transmission distance between a transmitting end and a receiving end of the wireless broadband ad hoc network is gradually increased and a channel condition is gradually deteriorated in a mobile environment.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention provides a wireless broadband ad hoc network transmission method, which comprises the following steps: the wireless ad hoc network sending node receives a wireless channel CQI fed back by a corresponding receiving node, and the sending node selects a physical resource allocation mode and a modulation coding mode according to the feedback CQI and carries out forward transmission with the receiving node next time;

(2): if the feedback CQI is lower than a first preset CQI threshold, the sending node determines physical time-frequency resources required by next transmission according to the feedback CQI, and notifies other nodes of the physical time-frequency resources in a broadcast mode in a sending subframe # n;

(3): the transmitting node performs data block transmission on P PRBs in the continuous m subframes from the subframe # n + K;

(4): for other sending nodes in the network with the received feedback CQI not lower than a first preset CQI threshold, the transmission of the other sending nodes does not occupy the P PRB resources in m continuous subframes starting from the subframe # n + K;

(5): if the physical time-frequency resources generated by a plurality of sending nodes partially or completely coincide, the sending nodes compete for the physical time-frequency resources according to the priority of the sent data blocks;

(6): if the distance between two sending nodes exceeds a preset distance threshold, the two sending nodes can simultaneously use the same physical time-frequency resource;

(7): if the number M of continuous subframes required by the sending node exceeds the maximum number M of subframes of resource allocation so that the code rate of the sent data block can meet the demodulation requirement of the receiving node, the sending node reduces the service to the service with smaller data blocks.

Preferably, in (1):

if the receiving node and the sending node are in communication for the first time and the sending node cannot predict the forward wireless channel condition, the existing physical resource allocation mode is adopted, and a modulation coding mode corresponding to the CQI grade which does not exceed a second preset CQI threshold is adopted for transmission;

if the receiving node and the sending node are not communicated for the first time, the receiving node carries out CQI estimation according to the last transmission and feeds back the estimated CQI to the sending node;

and if the feedback CQI is lower than a first preset CQI threshold and the sending node only transmits data to the receiving node in a sending subframe, the sending node adopts the existing physical resource allocation mode and adopts a modulation coding mode corresponding to the feedback CQI grade for transmission.

Preferably, in (3):

in the subframe # n + K, the P PRBs on the first x OFDM symbols are used to carry control information, and the modulation coding information and the physical time-frequency resource information corresponding to the data block sent by the sending node are mapped on the physical resources on the first x OFDM symbols.

Preferably, in (5),

if the physical time-frequency resources generated by the plurality of sending nodes are completely overlapped, the data block with high service priority preferentially uses the physical time-frequency resources; if the service priorities are the same, the HARQ retransmission data block preferentially uses the physical time-frequency resource; if the data blocks are newly transmitted or retransmitted, the transmitting node preferentially uses the physical time-frequency resource with the highest channel quality on the physical resource; for the sending node which can not compete to the physical time frequency resource, rebroadcasting the physical time frequency resource information in a subframe after the subframe # n, and carrying out resource competition again;

if the frequency domain resources of the physical time-frequency resources generated by the plurality of sending nodes are completely or partially overlapped and the K values are different, the sending node with the minimum K value preferentially uses the physical time-frequency resources; if the K value is the same, the transmitting node with high channel quality on the superposed PRB resource uses the physical time frequency resource; and delaying transmission of the transmitting nodes which do not acquire the physical time frequency resources, or transmitting the PRB resources which do not occupy the superposition, or re-competing resources according to the way when the physical time frequency resources generated by a plurality of transmitting nodes are completely superposed.

The invention has the beneficial effects that:

(1) The invention increases the coverage of the sending node by changing the physical resource allocation mode and reduces the network deployment cost.

(2) In the mobile environment, the service of the sending node is changed along with the transmission distance, and the uninterrupted service is realized by orderly reducing the service mode along with the increase of the transmission distance.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a frame structure of a wireless broadband ad hoc network based on TD-LTE technology in the prior art;

FIG. 2 is a diagram illustrating physical time-frequency resource partitioning in the prior art;

FIG. 3 is a diagram illustrating the control channel and data channel division within one sub-frame in the prior art;

FIG. 4 shows modulation schemes and code rates corresponding to CQI grades in the prior art;

FIG. 5 is a timing diagram illustrating the sending of a data block by a sending node according to the present invention;

FIG. 6 is a diagram of resource allocation for multiple transmitting nodes within m consecutive subframes according to the present invention;

FIG. 7 is a schematic diagram of physical resource overlapping corresponding to two sending nodes according to the present invention;

FIG. 8 is a diagram illustrating a change in transmission distance for a transmission service according to the present invention;

fig. 9 is a flow chart of an aspect of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples

The invention provides a wireless broadband ad hoc network transmission method, which comprises the following steps:

(1): the wireless ad hoc network sending node receives a wireless channel CQI fed back by a corresponding receiving node, and the sending node selects a physical resource allocation mode and a modulation coding mode according to the feedback CQI and carries out forward transmission with the receiving node next time;

if the following conditions are met, the sending node adopts a physical resource allocation mode in the prior art, otherwise, the physical resource allocation modes from (2) to (7) are adopted:

1) If the receiving node and the transmitting node communicate for the first time, and the transmitting node cannot predict the situation of the forward wireless channel, a physical resource allocation mode in the prior art is adopted (in the prior art, the physical time-frequency resource allocated by one-time transmission usually comprises a plurality of PRBs in one subframe, and one-time transmission cannot occupy a plurality of continuous subframes at the same time, namely: transmitting on the P PRB resources in the allocated subframe # k, which is also the same as the physical resource allocation manner in the following prior art), and transmitting by using a modulation coding manner corresponding to a CQI level that does not exceed a second preset CQI threshold;

2) If the receiving node and the sending node are not in first communication, the receiving node carries out CQI estimation according to the last transmission and feeds back the estimated CQI to the sending node; the CQI estimation and feedback are the prior art, the performance of the CQI estimation depends on an algorithm, and the scheme assumes that a receiving end can carry out the CQI estimation and feedback without difference. If the time interval between the next transmission and the last transmission exceeds a certain threshold, the channel condition is considered to be changed, the CQI estimated and fed back according to the last transmission cannot be used as the reference of the next transmission, and the sending node adopts a physical resource allocation mode in the prior art and adopts a modulation coding mode corresponding to the CQI grade which does not exceed a second preset CQI threshold to carry out transmission;

3) And if the feedback CQI is lower than a first preset CQI threshold and the sending node only transmits data to the receiving node in a sending subframe, the sending node adopts a physical resource allocation mode in the prior art and adopts a modulation coding mode corresponding to the feedback CQI grade for transmission.

(2): if the feedback CQI is lower than the first preset CQI threshold, the sending node determines, according to the feedback CQI, the physical time-frequency resource required for the next transmission, and notifies, in a broadcast manner, the other nodes of the physical time-frequency resource in the sending subframe # n, as shown in fig. 5;

assuming that the size of a data packet sent each time is fixed under the condition of fixed service, when data block transmission is performed in a modulation coding mode corresponding to a first preset CQI threshold, the number of PRBs required in one subframe is fixed (referred to as reference PRB number); if the feedback CQI is lower than a first preset CQI threshold and resources with the reference PRB number are allocated in a subframe at most, the transmission code rate of the data block is higher than the code rate corresponding to the feedback CQI grade, so that the receiving node cannot demodulate correctly; therefore, under the condition that the number of the frequency domain PRBs is limited, the time domain resource allocation amount can be increased, and the transmission power of the data block is improved while the physical time frequency resource amount is ensured;

for a wireless broadband ad hoc network with a central node, physical time-frequency resources corresponding to data blocks of sending nodes can be distributed by the central node, for a wireless broadband ad hoc network without the central node, the sending nodes can distribute the physical time-frequency resources corresponding to the data blocks by themselves, when the physical time-frequency resources are distributed, PRB resources with better transmission performance can be selected in a physical layer measurement mode, the number of PRBs is not less than the number of PRBs required for ensuring channel estimation performance and not more than the reference number of PRBs, time-domain resources at least comprise one subframe and at most comprise M subframes, and the value of M is limited in the step (3);

the sending node sends the determined physical time-frequency resource to other nodes in the network in a broadcasting mode, and for the wireless broadband ad hoc network with the central node, the central node can schedule the resource of the other nodes to avoid the physical time-frequency resource; and for the wireless broadband ad hoc network without the central node, other nodes avoid the physical time-frequency resource when transmitting data blocks after receiving the physical time-frequency resource information.

(3): the transmitting node performs data block transmission on P PRBs in the continuous m subframes from the subframe # n + K; wherein K is greater than 0, and is a subframe interval between a subframe for broadcasting physical time-frequency resources for a transmitting node and a subframe for starting transmitting a data block; m is less than or equal to M, the number of subframes contained in the physical time-frequency resource determined by the sending node is the number of the maximum subframes distributed by the resource; p is the PRB number contained in the physical time frequency resource determined by the sending node;

after broadcasting physical resource time frequency, a sending node starts to transmit data blocks after K subframes, so that a broadcast message can be transmitted to other nodes in a network in a multi-hop mode, the value of K is related to factors such as network scale, node data and distance between nodes, and the value of K is smaller for a network with less node number and smaller coverage area; parameters M and P are the number of subframes and the number of PRBs contained in the physical time-frequency resource determined by the sending node in the step 2, the minimum value of M is 1, and the maximum value of M does not exceed the maximum number of subframes M;

for subframe # n + K, the P PRBs on the first x OFDM symbols may be used to carry control information, and the modulation coding information and the physical time-frequency resource information corresponding to the data block sent by the sending node are mapped on physical resources on the first x OFDM symbols, where 0-x is less than or equal to 3; however, for the sub-frame # n + K +1 to the sub-frame # n + K + m, the P PRBs on the first x OFDM symbols cannot be used for carrying control information; for the receiving node, it has been deduced through the broadcast message that the PRB on the first x OFDM symbols of the m-1 subframes cannot carry control information, and then the control information is not blindly detected on these physical resources, as shown in fig. 6;

for the sending data block of the sending node, the processing steps such as coding, scrambling, modulation, mapping and the like are the same as those in the prior art; and when physical resource mapping is carried out, mapping is carried out on the P PRB resources of the m subframes in a mode of firstly carrying out frequency domain and then carrying out time domain.

(4): for other sending nodes in the network with the received feedback CQI not lower than a first preset CQI threshold, the transmission of the other sending nodes does not occupy the P PRB resources in m continuous subframes starting from the subframe # n + K;

for the other sending nodes, the physical resource allocation mode and the resource mapping mode are the same as those in the prior art; through the broadcast message of the sending node, the resource allocation in the m subframes avoids the P PRB resources, and the mutual interference is avoided.

(5): if the physical time-frequency resources generated by the plurality of sending nodes partially or completely coincide, the sending nodes compete for the physical time-frequency resources according to the priority of the sent data blocks;

in (2), the sending node notifies the physical time-frequency resources to other nodes in a subframe # n in a broadcast manner, but before one or more nodes receive the broadcast message, the physical time-frequency resources used by the data transmission of the sending node may be determined, the two physical time-frequency resources may be partially or completely overlapped, the physical time-frequency resources include time domain and frequency domain parts, the following 1 means that the time domain and the frequency domain are overlapped, the following 2 means that the frequency domain is completely overlapped or partially overlapped, the time domain is not completely overlapped, two rectangles can be completely overlapped in width, and the length can be staggered;

1. if the physical time-frequency resources broadcast by two or more sending nodes are completely overlapped (both time domain and frequency domain are overlapped), the values of n, K and P corresponding to the two or more sending nodes are completely the same, and the physical time-frequency resources can be contended according to the priority of the sending data block: the data block with high service priority preferentially uses the physical time-frequency resource; if the service priorities are the same, the physical time-frequency resource is preferentially used by a Hybrid Automatic Repeat reQuest (HARQ) retransmission data block; and if the data blocks are newly transmitted or retransmitted, the transmitting node preferentially uses the physical time-frequency resource with the highest channel quality on the physical resource. For the sending node which can not compete to the physical time frequency resource, rebroadcasting the physical time frequency resource information in a subframe after the subframe # n, and carrying out resource competition again;

2. if the frequency domain resources of the physical time-frequency resources broadcast by two or more sending nodes are completely or partially overlapped, but the time domain starting subframes are different, that is, the values of K are different (when the subframes # n corresponding to the multiple nodes are the same, but the values of K are different, so that the values of n + K are also different, which corresponds to the complete or partial overlapping of the frequency domains, but are not consistent in the time domain), the sending node with the minimum value of K preferentially uses the physical time-frequency resources. And if the time domain starting subframes are the same, namely the K values are the same, the transmitting node with high channel quality on the overlapped PRB resources uses the physical time-frequency resources.

And (3) for the sending node which does not acquire the physical time-frequency resource, the sending can be postponed, or the sending can be performed without occupying the overlapped PRB resource, or the resource can be competed again according to the step (1).

(6): if the distance between two sending nodes exceeds a preset distance threshold, the two sending nodes can be considered not to interfere with each other, and the two sending nodes can simultaneously use the same physical time-frequency resource;

(7): for the sending node, if the number M of continuous subframes required by the sending node exceeds the maximum number M of subframes allocated by resources, the code rate of the sent data block can meet the demodulation requirement of the receiving node, and the sending node reduces the service into the service with smaller data blocks;

for the transceiving node with too long transmission distance and too poor channel quality, even if the physical resource allocation mode is adopted, the current service cannot be supported, and the service mode needs to be changed, so that the size of the data block needs to be reduced, for example, from video service to data service or voice service. When the data block is reduced but the physical resource is not changed, the code rate of the data block is reduced.

For further explanation, assume a wireless broadband ad hoc network including N nodes, where a node a sends a data block to a node H for communication, and if the node a sends the data block to the node H for the first time and the node a cannot predict the situation of a forward wireless channel, the node a adopts a physical resource allocation manner in the prior art and adopts a modulation and coding manner corresponding to a CQI of a lower level for transmission (that is, adopts a modulation and coding manner corresponding to a CQI level that does not exceed a second preset CQI threshold for transmission), for example, adopts a modulation and coding manner corresponding to a CQI level of 0 or 1. If the node A and the node H are not in first communication, the node H estimates CQI of a wireless channel according to previous transmission and feeds the CQI back to the node A, if the time interval between the current transmission and the previous transmission of the node A exceeds a certain threshold, for example, exceeds 100ms, the channel condition is considered to have changed, the fed-back CQI cannot be used as a reference of the current transmission, and the node A adopts the same transmission scheme as the first communication. Under the condition that the feedback CQI is still effective but is lower than a preset first preset CQI threshold (for example, the threshold is CQI level 7), if the node a transmits data only to the node H in the transmission subframe, the node a uses a physical resource allocation manner in the prior art and uses a modulation and coding manner corresponding to the feedback CQI level for transmission.

Assuming that the size of the data packet sent each time is fixed under the condition of fixed service, when the data block transmission is performed in the modulation coding mode corresponding to the first preset CQI threshold, the number of PRBs required in one subframe is fixed, and this number of PRBs may be used as the reference number of PRBs. If the feedback CQI is not in the condition of the first preset CQI threshold, the physical time-frequency resources allocated by the node comprise P PRB resources on m continuous subframes, and P is not lower than the number of PRBs required by the channel estimation performance and not higher than the reference PRB number. M is minimum 1 and maximum M, where M is the maximum number of subframes for resource allocation, e.g., M =4. For the wireless broadband ad hoc network with the central node, the physical time-frequency resource of the node A is distributed by the central node. For the wireless broadband ad hoc network without the central node, the node A allocates the physical time-frequency resource corresponding to the data block. When physical time-frequency resources are allocated, PRB resources with better transmission performance can be selected in a physical layer measurement mode.

The node A sends the determined physical time-frequency resource to other nodes in the network in a broadcast mode in the subframe # n, and the purpose is to enable the other nodes in the network to know that the physical time-frequency resource is occupied and avoid the resource when the other nodes transmit. However, for a wireless ad hoc network with a large number of hops, some nodes need to receive the broadcast message after two hops, and before receiving the broadcast message, the nodes already determine the physical time-frequency resources used by their own data transmission, so that resource conflict occurs.

If there is a full or partial overlap of the physical time-frequency resources of the sending node B and the node a, but the node B and the node a are distributed in opposite directions of the network edge, and the distance between the two exceeds a preset distance threshold, for example, 5 km, it can be considered that the node B and the node a use the same physical time-frequency resource without mutual interference, and the node B and the node a can use the same physical time-frequency resource.

If the physical time-frequency resources of the sending node B and the node A are completely overlapped, the physical time-frequency resources can be contended according to the priorities of the sending data blocks corresponding to the node A and the node B: the data block with high service priority preferentially uses the physical time-frequency resource; if the service priorities are the same, the HARQ retransmission data block preferentially uses the physical time-frequency resource; and if the data blocks are newly transmitted or retransmitted, the transmitting node preferentially uses the physical time-frequency resource with the highest channel quality on the physical resource. And for the sending node which can not compete to the physical time-frequency resource, rebroadcasting the physical time-frequency resource information in a subframe after the subframe # n, and carrying out resource competition again.

If the frequency domain resources of the physical time frequency resources of the sending node B and the node A are completely or partially overlapped, but the time domain starting subframes of the physical time frequency resources are different, the sending node with the minimum starting subframe number preferentially uses the physical time frequency resources. And if the time domain starting subframes are the same, the transmitting node with high channel quality uses the physical time-frequency resource on the overlapped PRB resource. Assuming that the node a preferentially uses the physical time-frequency resource through a contention mode, the node B may defer transmission, or may not occupy the overlapped PRB resource for transmission, or may contend for the resource again.

The node A starts from a subframe # n + K and performs data block transmission on P PRBs in continuous m subframes, wherein K >0 is a subframe interval between a subframe for broadcasting physical time-frequency resources by a transmitting node and a subframe for starting transmitting data blocks, the value is related to factors such as network scale, node data, distance between nodes and the like, and the value of K is smaller for a network with less node number and smaller coverage area; m is more than or equal to the number of subframes contained in the physical time-frequency resources determined by the sending node, and M is the maximum number of subframes allocated by the resources; p is the number of PRBs contained in the physical time-frequency resource determined by the transmitting node. For subframe # n + K, the P PRBs on the first three OFDM symbols may be used to carry control information, and the modulation and coding information and the physical time-frequency resource information corresponding to the data block sent by the sending node are mapped to physical resources on the first three OFDM symbols. However, for subframe # n + K +1 to subframe # n + K + m, the P PRBs on the first three OFDM symbols cannot be used to carry control information. For a receiving node, it has been deduced through a broadcast message that the PRBs on the first three OFDM symbols of the m-1 subframes cannot carry control information, and then the control information is not blindly detected on these physical resources. The processing steps, such as encoding, scrambling, modulation, mapping, etc., for the transmitted data block of the transmitting node are the same as in the prior art. And when physical resource mapping is carried out, mapping to the P PRB resources of the m subframes according to a mode of firstly mapping a frequency domain to a time domain.

Assuming that the receiving node H is in a moving state and is further away from the node a, the quality of the wireless channel is further and further poor. If the video service is transmitted all the time between the node A and the node H, the number M of the continuous sub-frames allocated to the video service data block increases with the transmission distance, and when a certain distance is reached, M = M. If the distance between the node A and the node B is still increased, the allocated physical time-frequency resources can not enable the transmission code rate to meet the demodulation requirement of the receiving node H, the node A reduces the service to the data service, and the size of the data block transmitted each time is reduced. If the distance between the two is further increased, the service can be gradually reduced to voice service or short message service, and the service between the node A and the node H is interrupted only when a certain limit condition is reached.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (3)

1. A wireless broadband ad hoc network transmission method, comprising:

(1): the wireless ad hoc network sending node receives a wireless channel CQI fed back by a corresponding receiving node, and the sending node selects a physical resource allocation mode and a modulation coding mode according to the feedback CQI and carries out forward transmission with the receiving node next time;

(2): if the feedback CQI is lower than a first preset CQI threshold, the sending node determines physical time-frequency resources required by next transmission according to the feedback CQI, and informs other nodes of the physical time-frequency resources in a broadcast mode in a sending subframe # n;

(3): the transmitting node performs data block transmission on P PRBs in the continuous m subframes from the subframe # n + K;

(4): for other sending nodes in the network with the received feedback CQI not lower than a first preset CQI threshold, the transmission of the other sending nodes does not occupy the P PRB resources in m continuous subframes starting from the subframe # n + K;

(5): if the physical time-frequency resources generated by a plurality of sending nodes partially or completely coincide, the sending nodes compete for the physical time-frequency resources according to the priority of the sent data blocks;

(6): if the distance between two sending nodes exceeds a preset distance threshold, the two sending nodes can simultaneously use the same physical time-frequency resource;

(7): if the number M of continuous subframes required by the sending node exceeds the maximum number M of subframes allocated by resources, the code rate of the sent data block can meet the demodulation requirement of the receiving node, and the sending node reduces the service into the service with smaller data blocks;

if the following conditions are met, the sending node adopts a physical resource allocation mode in the prior art, otherwise, the physical resource allocation modes from (2) to (7) are adopted:

if the receiving node and the sending node are in communication for the first time and the sending node cannot predict the forward wireless channel condition, the existing physical resource allocation mode is adopted, and a modulation coding mode corresponding to the CQI grade which does not exceed a second preset CQI threshold is adopted for transmission; the existing physical resource allocation method specifically includes: transmitting on the P PRB resources within the allocated subframe # k;

if the receiving node and the sending node are not in first communication, the receiving node carries out CQI estimation according to the last transmission and feeds back the estimated CQI to the sending node;

and if the feedback CQI is lower than a first preset CQI threshold and the sending node only transmits data to the receiving node in a sending subframe, the sending node adopts the existing physical resource allocation mode and adopts a modulation coding mode corresponding to the feedback CQI grade for transmission.

2. A wireless broadband ad hoc network transmission method according to claim 1, wherein in (3):

in the subframe # n + K, the P PRBs on the first x OFDM symbols are used to carry control information, and the modulation coding information and the physical time-frequency resource information corresponding to the data block sent by the sending node are mapped on the physical resources on the first x OFDM symbols.

3. A wireless broadband ad hoc network transmission method according to claim 1, wherein in (5),

if the physical time-frequency resources generated by the plurality of sending nodes are completely overlapped, the data block with high service priority preferentially uses the physical time-frequency resources; if the service priorities are the same, the HARQ retransmission data block preferentially uses the physical time-frequency resource; if the data blocks are newly transmitted or retransmitted, the transmitting node preferentially uses the physical time-frequency resource with the highest channel quality on the physical resource; for the sending node which can not compete to the physical time-frequency resource, rebroadcasting the physical time-frequency resource information in a subframe after the subframe # n, and carrying out resource competition again;

if the frequency domain resources of the physical time-frequency resources generated by the plurality of sending nodes are completely or partially overlapped and the K values are different, the sending node with the minimum K value preferentially uses the physical time-frequency resources; if the K value is the same, the transmitting node with high channel quality on the superposed PRB resource uses the physical time frequency resource; and delaying transmission of the transmitting nodes which do not acquire the physical time frequency resources, or transmitting the PRB resources which do not occupy the superposition, or re-competing resources according to the way when the physical time frequency resources generated by a plurality of transmitting nodes are completely superposed.

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