CN105451240A

CN105451240A - Bidirectional cooperation anti-interference spectrum access method based on joint optimization of time and bandwidth

Info

Publication number: CN105451240A
Application number: CN201510755344.8A
Authority: CN
Inventors: 卢为党; 王梦云; 吴佳颖; 刘浩; 彭宏
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2015-11-09
Filing date: 2015-11-09
Publication date: 2016-03-30
Anticipated expiration: 2035-11-09
Also published as: CN105451240B

Abstract

A two-way cooperative anti-jamming spectrum access method based on joint optimization of time and bandwidth. In this method, the cognitive user accesses the spectrum of the primary user through two-way cooperation; if the cognitive user can help the primary user reach the target rate, then The primary user will allocate part of the time to the acquaintance user and authorize it to access its own spectrum; otherwise, the acquaintance user will not be allowed to access its own spectrum. After the cognitive user accesses the frequency spectrum of the primary user, it uses different bandwidths to send information about the primary user and itself. The present invention effectively eliminates the problems of mutual interference between the primary user and the cognitive user and spectrum loss caused by the half-duplex mode in a one-way cooperative mode, and improves user performance.

Description

A two-way cooperative anti-jamming spectrum access method based on joint optimization of time and bandwidth

技术领域technical field

本发明属于无线通信领域中的认知无线电通信技术领域，尤其是一种频谱接入方法。The invention belongs to the technical field of cognitive radio communication in the field of wireless communication, in particular to a frequency spectrum access method.

背景技术Background technique

随着无线通信的发展，无线通信用户不断增多，业务需求快速增长，有限的无线频谱资源逐渐成为制约无线通信系统发展的瓶颈。美国联邦通信委员会(FCC)的大量研究报告表明当前无线频谱的利用率很低，只有15％～85％，大部分频谱在多数时候并没有得到充分的利用，并且频谱使用情况非常不平衡，一些非授权频段占用过于拥挤，而某些授权频段则经常处于空闲状态。可见造成频谱资源紧缺的主要原因是现有的这种静态频谱管理方式和频谱分配策略。认知无线电技术能感知周围无线通信环境，在保证主用户正常通信不受影响的前提下，伺机接入授权频谱，通过一定的学习和决策算法，自适应地改变系统工作参数来适应运行环境的变化，可以对频谱在时间，频率，空间上进行多维复用，从而提升频谱资源的利用率。With the development of wireless communication, the number of wireless communication users continues to increase, and business demands grow rapidly. Limited wireless spectrum resources have gradually become a bottleneck restricting the development of wireless communication systems. A large number of research reports by the Federal Communications Commission (FCC) of the United States show that the utilization rate of the current wireless spectrum is very low, only 15% to 85%. Most of the spectrum is not fully utilized most of the time, and the spectrum usage is very unbalanced. Some Unlicensed frequency bands are overcrowded, while some licensed frequency bands are often idle. It can be seen that the main reason for the shortage of spectrum resources is the existing static spectrum management mode and spectrum allocation strategy. Cognitive radio technology can perceive the surrounding wireless communication environment. Under the premise of ensuring that the normal communication of the primary user is not affected, it waits for an opportunity to access the licensed spectrum. Through certain learning and decision-making algorithms, it adaptively changes the system operating parameters to adapt to the operating environment. The spectrum can be multi-dimensionally multiplexed in time, frequency, and space, thereby improving the utilization of spectrum resources.

在认知无线电共存式频谱接入方法中，认知用户被允许在满足一定前提下与主用户共用同一频段。然而在这种接入方法中，主用户与认知用户之间始终存在干扰，使得原本就非常有限的频谱资源得不到充分利用，主用户和认知用户的性能也会由于干扰受到影响。并且这种频谱接入方法是单向协作的，存在固有频谱效率的损失。In the cognitive radio coexistence spectrum access method, cognitive users are allowed to share the same frequency band with primary users under certain conditions. However, in this access method, there is always interference between the primary user and the cognitive user, so that the originally very limited spectrum resources are not fully utilized, and the performance of the primary user and the cognitive user is also affected by the interference. Moreover, this spectrum access method is one-way cooperative, and there is a loss of inherent spectrum efficiency.

发明内容Contents of the invention

针对现有共存式频谱接入技术中的缺陷，解决主用户和认知用户之间相互干扰的问题、克服频谱利用率不高的不足，本发明提供一种有效消除主用户和认知用户之间相互干扰的问题、提高频谱利用率的基于时间和带宽联合优化的双向协作抗干扰频谱接入方法。Aiming at the defects in the existing coexistence spectrum access technology, solving the problem of mutual interference between the primary user and the cognitive user, and overcoming the problem of low spectrum utilization, the present invention provides a method to effectively eliminate the gap between the primary user and the cognitive user. The problem of mutual interference among them, and a two-way cooperative anti-interference spectrum access method based on joint optimization of time and bandwidth to improve spectrum utilization.

本发明解决其技术问题所采用的技术方案是：The technical solution adopted by the present invention to solve its technical problems is:

一种基于时间和带宽联合优化的双向协作抗干扰频谱接入方法，无线电通信系统包括一个主系统和一个认知系统，主系统包括主用户A和主用户B，认知系统由认知用户发送端S和认知用户接收端D组成，能够模拟主系统中的无线电协议和系统参数；所述主系统支持中继功能，有一段W带宽组成的授权频谱；所述基于时间和带宽联合优化的双向协作抗干扰频谱接入方法包括以下步骤：A two-way cooperative anti-interference spectrum access method based on joint optimization of time and bandwidth. The radio communication system includes a primary system and a cognitive system. The primary system includes primary user A and primary user B. The cognitive system is sent by the cognitive user. Composed of terminal S and cognitive user receiving terminal D, it can simulate the radio protocol and system parameters in the main system; the main system supports the relay function and has a licensed spectrum consisting of a section of W bandwidth; the joint optimization based on time and bandwidth The two-way cooperative anti-interference spectrum access method includes the following steps:

1)认知用户以协作方式接入主用户的频谱，认知用户接收到主用户的信息后，通过解码转发协作方式帮助转发主用户的信息；1) Cognitive users access the spectrum of the primary user in a cooperative manner. After receiving the information of the primary user, the cognitive users help forward the information of the primary user through decoding and forwarding cooperation;

2)计算主用户A和B通过认知用户协作帮助后获得的速率R_A和R_B；2) Calculating the rates _RA and RB obtained by primary users A and _B through cognitive user cooperation;

3)如果R_A≥R_AT且R_B≥R_BT，则主用户就会分配一部分时间给认识用户，授权其接入自己的频谱，认知用户接入主系统的频谱后，利用一部分的带宽转发主用户的信息，利用剩余的带宽发送自己的信息；否则，主用户继续通过直传发送自己的信息；3) If R _A ≥ R _AT and R _B ≥ R _BT , the primary user will allocate part of the time to the acquaintance user, authorize it to access its own spectrum, and use a part of the bandwidth after the acquaintance user accesses the spectrum of the primary system Forward the main user's information and use the remaining bandwidth to send its own information; otherwise, the main user continues to send its own information through direct transmission;

主用户和认知用户之间的时间和带宽联合分配问题建模为：The problem of joint allocation of time and bandwidth between primary and cognitive users is modeled as:

$\underset{T T,, B B}{max max} {R R}_{S S} - - - - - - ((11))$

满足以下条件The following conditions

$\{\begin{matrix} {R R}_{A A} &GreaterEqual; &Greater Equal; {R R}_{A A T T} \\ {R R}_{B B} &GreaterEqual; &Greater Equal; {R R}_{B B T T} \\ 00 < < α α + + β β < < 11 \\ 00 < < n no + + m m < < 11 \\ 00 < < α α < < 11 \\ 00 < < β β < < 11 \\ 00 < < m m < < 11 \\ 00 < < n no < < 11 \end{matrix} - - - - - - ((22))$

其中R_AT和R_BT分别表示主用户A和B的目标速率，T＝{m,n}，B＝{α,β}，m和n分别表示主用户A和B在第一时隙和第二时隙发送自己信息所占的时间，α和β分别表示认识用户在第三个时隙帮助主用户A和B转发信息所用的带宽。R_A、R_B和R_S分别表示认知用户接入主用户频谱后，主用户A、主用户B和认知用户S获得的速率：where R _AT and R _BT represent the target rates of primary users A and B respectively, T={m,n}, B={α,β}, m and n represent primary users A and B in the first time slot and the first time slot respectively The time it takes for the second time slot to send its own information, α and β respectively represent the bandwidth used by the acquainted user to help the main user A and B forward information in the third time slot. R _A , R _B , and R _S represent the rates obtained by primary user A, primary user B, and cognitive user S after cognitive users access the spectrum of primary users, respectively:

R_A＝min{R_AS,R_SB}(3)R _A =min{R _AS , _RSB }(3)

R_B＝min{R_BS,R_SA}(4)R _B =min{R _BS ,R _SA }(4)

${R R}_{S S} = = ((11 - - m m - - n no)) ((11 - - α α - - β β)) {Wlog wlog}_{22} ((11 + + \frac{{P P}_{S S} {γ γ}_{S S D D.}}{33 {σ σ}^{22}})) - - - - - - ((55))$

其中，P_S表示认知用户S的发射功率，γ_SD表示认知用户发送端到认知用户接收端链路的信道增益，σ²表示噪声功率谱密度，R_AS和R_SB分别表示主用户A在第一个和第二个时隙获得的速率：Among them, PS represents the transmit power of cognitive user _S , γ _SD represents the channel gain of the link from the cognitive user sending end to the cognitive user receiving end, σ ² represents the noise power spectral density, R _AS and _RSB represent the primary user The rates obtained by A in the first and second slots:

${R R}_{A A S S} = = {mWlog wxya}_{22} ((11 + + \frac{{P P}_{A A} {γ γ}_{A A S S}}{{σ σ}^{22}})) - - - - - - ((66))$

${R R}_{S S B B} = = \{\begin{matrix} [[m m - - ((11 - - m m - - n no)) α α]] {R R}_{A A 11} + + ((11 - - m m - - n no)) {αR αR}_{A A 22} & m m &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) α α \\ [[((11 - - m m - - n no)) α α - - m m]] {R R}_{A A 33} + + {mR mR}_{A A 22} & m m < < ((11 - - m m - - n no)) α α \end{matrix} - - - - - - ((77))$

其中， $R_{A 1} = {Wlog}_{2} (1 + \frac{P_{A} γ_{A B}}{σ^{2}}), R_{A 2} = {Wlog}_{2} (1 + \frac{P_{S} γ_{S B}}{3 σ^{2}} + \frac{P_{A} γ_{A B}}{σ^{2}}),$ P_A表示主用户A的发射功率，γ_AS,γ_SB和γ_AB分别表示主用户A到认知用户发送端链路的信道增益，认知用户发送端到主用户B链路的信道增益和主用户A到主用户B链路的信道增益，R_BS和R_SA分别表示主用户B在第一个和第二个时隙获得的速率：in, $R_{A 1} = {wlog}_{2} (1 + \frac{P_{A} γ_{A B}}{σ^{2}}), R_{A 2} = {wlog}_{2} (1 + \frac{P_{S} γ_{S B}}{3 σ^{2}} + \frac{P_{A} γ_{A B}}{σ^{2}}),$ P _A represents the transmit power of the primary user A, γ _AS , γ _SB and γ _AB represent the channel gain of the link from the primary user A to the cognitive user sender, the channel gain of the link from the cognitive user sender to the primary user B, and The channel gain of the link from primary user A to primary user B, R _BS and R _SA represent the rate obtained by primary user B in the first and second time slots respectively:

${R R}_{B B S S} = = {nWlog wxya}_{22} ((11 + + \frac{{P P}_{B B} {γ γ}_{B B S S}}{{σ σ}^{22}})) - - - - - - ((88))$

${R R}_{S S A A} = = \{\begin{matrix} [[n no - - ((11 - - m m - - n no)) β β]] {R R}_{B B 11} ((11 - - m m - - n no)) {βR βR}_{B B 22} & n no &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) β β \\ [[((11 - - m m - - n no)) β β - - n no]] {R R}_{B B 33} + + {nR nR}_{B B 22} & n no < < ((11 - - m m - - n no)) β β \end{matrix} - - - - - - ((99))$

其中 $R_{B 1} = {Wlog}_{2} (1 + \frac{P_{B} γ_{B A}}{σ^{2}}), R_{B 2} = {Wlog}_{2} (1 + \frac{P_{S} γ_{S A}}{3 σ^{2}} + \frac{P_{B} γ_{B A}}{σ^{2}}),$ P_B表示主用户B的发射功率，γ_BS,γ_SA和γ_BA分别表示主用户B到认知用户发送端链路的信道增益，认知用户发送端到主用户A链路的信道增益和主用户B到主用户A链路的信道增益；in $R_{B 1} = {wlog}_{2} (1 + \frac{P_{B} γ_{B A}}{σ^{2}}), R_{B 2} = {wlog}_{2} (1 + \frac{P_{S} γ_{S A}}{3 σ^{2}} + \frac{P_{B} γ_{B A}}{σ^{2}}),$ P _B represents the transmit power of the primary user B, γ _BS , γ _SA and γ _BA represent the channel gain of the link from the primary user B to the cognitive user sender, the channel gain of the link from the cognitive user sender to the primary user A and Channel gain of the link from primary user B to primary user A;

通过数学优化方法获得上述的最优时间分配：The above optimal time allocation is obtained by mathematical optimization method:

${m m}^{* *} = = \frac{{R R}_{A A T T}}{{Wlog wlog}_{22} ((11 + + \frac{{P P}_{A A} {γ γ}_{A A S S}}{{σ σ}^{22}}))} - - - - - - ((1010))$

${n no}^{* *} = = \frac{{R R}_{B B T T}}{{Wlog wlog}_{22} ((11 + + \frac{{P P}_{B B} {γ γ}_{B B S S}}{{σ σ}^{22}}))} - - - - - - ((1111))$

根据R_SB和R_SA的不同取值，得到4种不同情况下的最优带宽分配：According to the different values of _RSB and _RSA , the optimal bandwidth allocation in 4 different situations is obtained:

①当 $\{\begin{matrix} m^{*} &GreaterEqual; (1 - m^{*} - n^{*}) α \\ n^{*} &GreaterEqual; (1 - m^{*} - n^{*}) β \end{matrix}$ 时，① when $\{\begin{matrix} m^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) α \\ {no}^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) β \end{matrix}$ hour,

$\{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} {R R}_{A A 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{A A 22} - - {R R}_{A A 11}))} \\ β β = = \frac{{R R}_{B B T T} - - {n no}^{* *} {R R}_{B B 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{B B 22} - - {R R}_{B B 11}))} \end{matrix} - - - - - - ((1212))$

②当 $\{\begin{matrix} m^{*} &GreaterEqual; (1 - m^{*} - n^{*}) α \\ n^{*} < (1 - m^{*} - n^{*}) β \end{matrix}$ 时，② when $\{\begin{matrix} m^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) α \\ {no}^{*} < (1 - m^{*} - {no}^{*}) β \end{matrix}$ hour,

$\{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} {R R}_{A A 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{A A 22} - - {R R}_{A A 11}))} \\ β β = = \frac{{R R}_{B B T T} - - {n no}^{* *} (({R R}_{B B 22} - - {R R}_{B B 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{B B 33}} \end{matrix} - - - - - - ((1313))$

③当 $\{\begin{matrix} m^{*} < (1 - m^{*} - n^{*}) α \\ n^{*} &GreaterEqual; (1 - m^{*} - n^{*}) β \end{matrix}$ 时，③ when $\{\begin{matrix} m^{*} < (1 - m^{*} - {no}^{*}) α \\ {no}^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) β \end{matrix}$ hour,

$\{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} (({R R}_{A A 22} - - {R R}_{A A 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{A A 33}} \\ β β = = \frac{{R R}_{B B T T} - - {n no}^{* *} {R R}_{B B 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{B B 22} - - {R R}_{B B 11}))} \end{matrix} - - - - - - ((1414))$

④当 $\{\begin{matrix} m^{*} < (1 - m^{*} - n^{*}) α \\ n^{*} < (1 - m^{*} - n^{*}) β \end{matrix}$ 时，④ when $\{\begin{matrix} m^{*} < (1 - m^{*} - {no}^{*}) α \\ {no}^{*} < (1 - m^{*} - {no}^{*}) β \end{matrix}$ hour,

$\{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} (({R R}_{A A 22} - - {R R}_{A A 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{A A 33}} \\ β β = = \frac{{R R}_{B B T T} - - {n no}^{* *} (({R R}_{B B 22} - - {R R}_{B B 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{B B 33}} \end{matrix} - - - - - - ((1515)) . .$

进一步，所述步骤2)中，认知用户通过三个时隙解码转发协作方式接入主用户的频谱；Further, in the step 2), the cognitive user accesses the frequency spectrum of the primary user through three time slot decoding and forwarding cooperation methods;

在第1个时隙，主用户A用m时隙向认知用户S发送信息，A→S链路的传输速率为:In the first time slot, primary user A uses m time slots to send information to cognitive user S, and the transmission rate of A→S link is:

在第2个时隙，主用户B用n时隙向认知用户S端发送信息，B→S链路的传输速率为:In the second time slot, the primary user B uses n time slots to send information to the cognitive user S, and the transmission rate of the B→S link is:

在第3个时隙，认知用户S利用αW带宽和P_S/3的功率来帮助主用户A传输信息，用βW带宽和P_S/3的功率来帮助主用户B传输信息，经过最大比合并，S→B链路和S→A链路的传输速率分别为：In the third time slot, the cognitive user _S uses the αW bandwidth and the power of PS /3 to help the primary user A to transmit information, and uses the _βW bandwidth and the power of PS /3 to help the primary user B transmit information. After the maximum ratio Combined, the transmission rates of the S→B link and the S→A link are:

${R R}_{S S B B} = = \{\begin{matrix} [[m m - - ((11 - - m m - - n no)) α α]] {R R}_{A A 11} + + ((11 - - m m - - n no)) {αR αR}_{A A 22} & m m &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) α α \\ [[((11 - - m m - - n no)) α α - - m m]] {R R}_{A A 33} + + {mR mR}_{A A 22} & m m < < ((11 - - m m - - n no)) α α \end{matrix} - - - - - - ((99))$

${R R}_{S S A A} = = \{\begin{matrix} [[n no - - ((11 - - m m - - n no)) β β]] {R R}_{B B 11} + + ((11 - - m m - - n no)) {βR βR}_{B B 22} & n no &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) β β \\ [[((11 - - m m - - n no)) β β - - n no]] {R R}_{B B 33} + + {nR nR}_{B B 22} & n no < < ((11 - - m m - - n no)) β β \end{matrix} - - - - - - ((77))$

所以主用户A和B通过三个时隙在认知用户S的帮助下获得的速率分别为：Therefore, the rates obtained by primary users A and B with the help of cognitive user S through three time slots are:

R_A＝min{R_AS,R_SB}(3)R _A =min{R _AS , _RSB }(3)

R_B＝min{R_BS,R_SA}(4)R _B =min{R _BS ,R _SA }(4)

同时，认知用户利用剩余的(1-α-β)W带宽和(1-m-n)时隙来发送自己的信息，所以认知用户获得的速率为：At the same time, cognitive users use the remaining (1-α-β)W bandwidth and (1-m-n) time slots to send their own information, so the rate obtained by cognitive users is:

${R R}_{S S} = = ((11 - - m m - - n no)) ((11 - - α α - - β β)) {Wlog wlog}_{22} ((11 + + \frac{{P P}_{S S} {γ γ}_{S S D D.}}{33 {σ σ}^{22}})) - - - - - - ((55)) . .$

本发明的技术构思为：由于共存式频谱接入方法中，认知用户和主用户使用相同的频谱同时进行通信，互相之间始终存在干扰，使得原本就非常有限的频谱资源得不到充分利用，主用户和认知用户的性能也会由于干扰受到影响。而且这种频谱接入方法使用单向协作方式，由于其半双工的工作模式造成了频谱效率的损失。本专利方法中认知用户通过双向协作的方式接入主用户的频谱，主用户和认知用户分别通过不同的时间和带宽来发送信息，能够有效解决主用户和认知用户之间的干扰问题。同时，认知系统以双向协作方式接入主用户的频谱，能够提高频谱利用率。The technical idea of the present invention is: in the coexistence spectrum access method, the cognitive user and the primary user use the same spectrum to communicate at the same time, and there is always interference between each other, so that the originally very limited spectrum resources cannot be fully utilized , the performance of primary users and cognitive users will also be affected due to interference. Moreover, this spectrum access method uses a one-way cooperative mode, which causes a loss of spectrum efficiency due to its half-duplex working mode. In this patent method, the cognitive user accesses the frequency spectrum of the primary user through two-way cooperation, and the primary user and the cognitive user send information through different time and bandwidth, which can effectively solve the interference problem between the primary user and the cognitive user . At the same time, the cognitive system accesses the spectrum of the primary user in a two-way cooperative manner, which can improve spectrum utilization.

本发明的有益效果主要表现在：(1)消除了共存式频谱接入方法中主用户和认知用户的干扰问题；(2)提高了频谱利用率。The beneficial effects of the present invention are mainly manifested in: (1) eliminating the interference problem of the primary user and the cognitive user in the coexistence spectrum access method; (2) improving the utilization rate of the spectrum.

附图说明Description of drawings

图1是本发明方法的双向协作抗干扰频谱接入模型示意图，其中h_ij，i,j∈{A,B,S,D}，i≠j，为瑞利平坦衰落信道的信道系数，且h_ij＝h_ji，服从其中v为路径损耗指数，d_ij为各发射端与接收端之间的归一化距离，(a)为主用户A和B广播各自的信息，(b)为认知用户S广播主用户和自己的信息。Fig. 1 is a schematic diagram of the two-way cooperative anti-interference spectrum access model of the method of the present invention, wherein h _ij , i, j ∈ {A, B, S, D}, i≠j, is the channel coefficient of the Rayleigh flat fading channel, and h _ij = h _ji , subject to where v is the path loss index, d _ij is the normalized distance between each transmitting end and receiving end, (a) broadcasts the respective information for the main users A and B, (b) broadcasts the main user and B for the cognitive user S own information.

图2是本发明方法中时间和带宽联合优化系数α、β、m和n随S位置的变化图。Fig. 2 is a graph showing the variation of time and bandwidth joint optimization coefficients α, β, m and n with the position of S in the method of the present invention.

图3是当认知用户获得频谱接入时，主用户和认知用户的传输速率随S位置的变化图。Fig. 3 is a graph showing the variation of the transmission rate of the primary user and the cognitive user with the position of S when the cognitive user obtains spectrum access.

具体实施方式detailed description

下面结合附图对本发明作进一步描述。The present invention will be further described below in conjunction with the accompanying drawings.

参照图1～图3，一种基于时间和带宽联合优化的双向协作抗干扰频谱接入方法，是基于现有的无线电通信系统实现的，所述无线电通信系统包括一个主系统和一个认知系统，其中主系统由主用户A和主用户B组成，主系统支持中继功能，有一段W带宽组成的授权频谱，认知系统由一个认知用户发送端S和认知接收端D组成。认知系统能够模拟主系统中的无线电协议和系统参数。Referring to Figures 1 to 3, a two-way cooperative anti-interference spectrum access method based on joint optimization of time and bandwidth is implemented based on the existing radio communication system, and the radio communication system includes a main system and a cognitive system , where the primary system consists of primary user A and primary user B. The primary system supports the relay function and has a licensed spectrum consisting of a bandwidth of W. The cognitive system consists of a cognitive user sender S and a cognitive receiver D. The cognitive system is capable of simulating the radio protocol and system parameters in the host system.

本实施方式的方法中，认知用户以双向协作方式接入主用户的频谱。认知用户接收到主用户的信息后，通过解码转发协作方式帮助转发主用户的信息。如果主用户A和B通过认知用户协作帮助后获得的速率R_A和R_B都大于自己的目标速率，即R_A≥R_AT和R_B≥R_BT，则主用户就会分配一部分时间给认识用户，授权其接入自己的频谱，认知用户接入主系统的频谱后，利用一部分的带宽转发主用户的信息，利用剩余的带宽发送自己的信息；否则，主用户继续通过直传发送自己的信息。In the method of this embodiment, the cognitive user accesses the frequency spectrum of the primary user in a two-way cooperative manner. After the cognitive user receives the information of the main user, it helps to forward the information of the main user through decoding and forwarding cooperation. If the rates R _A and RB obtained by primary users A and _B through the cooperation of cognitive users are both greater than their target rates, that is, R _A ≥ R _AT and _RB ≥ R _BT , then the primary user will allocate part of the time to Recognize the user, authorize it to access its own spectrum, and use a part of the bandwidth to forward the primary user's information after recognizing the user's access to the primary system's spectrum, and use the remaining bandwidth to send its own information; otherwise, the primary user continues to send through direct transmission own information.

本实施方式中认知用户接入主用户频谱后主用户A和B的传输速率R_A和R_B，以及认知用户获得的速率R_S可以通过如下方法获得：In this embodiment, after the cognitive user accesses the spectrum of the primary user, the transmission rates R _A and RB of the primary user A and _B , and the rate _RS obtained by the cognitive user can be obtained by the following method:

认知用户通过三个时隙解码转发协作方式接入主用户的频谱；在第1个时隙，主用户A用m时隙向认知用户S发送信息，A→S链路的传输速率为:Cognitive users access the spectrum of the primary user through decoding and forwarding cooperation in three time slots; in the first time slot, primary user A uses m time slots to send information to cognitive user S, and the transmission rate of the A→S link is :

R_A＝min{R_AS,R_SB}(3)R _A =min{R _AS , _RSB }(3)

R_B＝min{R_BS,R_SA}(4)R _B =min{R _BS ,R _SA }(4)

本实施方式中的时间和带宽分配方法具体为：The time and bandwidth allocation method in this embodiment is specifically:

主用户和认知用户之间的时间和带宽分配可以建模为：The time and bandwidth allocation between primary and cognitive users can be modeled as:

$\underset{T T,, B B}{max max} {R R}_{S S} - - - - - - ((11))$

满足以下条件The following conditions

①当 $\{\begin{matrix} m^{*} &GreaterEqual; (1 - m^{*} - n^{*}) α \\ n^{*} &GreaterEqual; (1 - m^{*} - n^{*}) β \end{matrix}$ 时，①When $\{\begin{matrix} m^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) α \\ {no}^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) β \end{matrix}$ hour,

本实施例的基于时间和带宽联合优化的双向协作抗干扰频谱接入方法，能够有效消除共存式频谱接入方法中主用户和认知用户的干扰问题，并且能够提高频谱利用率。The two-way cooperative anti-interference spectrum access method based on joint optimization of time and bandwidth in this embodiment can effectively eliminate the interference problem of primary users and cognitive users in the coexistence spectrum access method, and can improve spectrum utilization.

本实施例的频谱接入方法中，认知用户在主用户授权给其的第三个时隙，占用时间1-m-n，接入主用户的频谱。认知用户利用一部分接入获得的αW带宽帮助转发主用户A的信息，利用βW带宽帮助转发主用户B的信息，利用剩余的(1-α-β)W带宽发送自己的信息。主用户和认知用户分别通过不同的时间和带宽发送信息，互相之间不会产生干扰。在本实施方式中，假设A，B和S位于同一条直线上，A和B分别位于(0，0)和(1，0)处。S在X正半轴由A向B移动，D位于S正上方0.4处。因此d_AB＝1，d_BS＝1-d_AS，d_SD＝0.4。假设路径损耗指数v＝4，授权带宽W＝1，噪声功率谱密度σ²＝1，主用户发送功率和认知用户发送功率分别为P_A＝P_B＝10dB和P_S＝20dB。图2中显示了本发明中频谱分配方法的最优时间和带宽联合分配。In the spectrum access method of this embodiment, the cognitive user accesses the spectrum of the primary user for a period of 1-mn in the third time slot authorized by the primary user. Cognitive users use part of the αW bandwidth obtained by access to help forward the information of the primary user A, use the βW bandwidth to help forward the information of the primary user B, and use the remaining (1-α-β)W bandwidth to send their own information. The primary user and the cognitive user send information through different time and bandwidth respectively, without interfering with each other. In this embodiment, it is assumed that A, B and S are located on the same straight line, and A and B are located at (0,0) and (1,0) respectively. S moves from A to B on the positive semi-axis of X, and D is located 0.4 directly above S. Therefore d _AB =1, d _BS =1-d _AS , d _SD =0.4. Assuming path loss index v=4, authorized bandwidth W=1, noise power spectral density σ ² =1, primary user transmit power and cognitive user transmit power are P _A =P _B =10dB and P _S =20dB respectively. Fig. 2 shows the joint optimal time and bandwidth allocation of the frequency spectrum allocation method in the present invention.

本实施例的频谱接入方法有效提升了频谱利用率。图3中显示了采用本发明的频谱接入方法后主用户和认知用户的速率，可以看出采用本发明的频谱接入方法后，在主用户达能达到目标速率的同时，认知用户也能获得较大的传输速率。The spectrum access method in this embodiment effectively improves spectrum utilization. Figure 3 shows the rates of primary users and cognitive users after adopting the spectrum access method of the present invention. It can be seen that after adopting the spectrum access method of the present invention, while the primary user can reach the target rate, the cognitive users can also reach the target rate. A higher transmission rate can be obtained.

Claims

1. A two-way cooperative anti-interference spectrum access method based on joint optimization of time and bandwidth. The radio communication system includes a main system and a cognitive system. The main system includes a main user A and a main user B. The cognitive system consists of a cognitive system Composed of user sending end S and cognitive user receiving end D, it can simulate the radio protocol and system parameters in the main system; it is characterized in that: the main system supports relay function and has a licensed spectrum consisting of a section of W bandwidth; The two-way cooperative anti-interference spectrum access method for joint optimization of time and bandwidth includes the following steps:

1) Cognitive users access the spectrum of the primary user in a cooperative manner. After receiving the information of the primary user, the cognitive users help forward the information of the primary user through decoding and forwarding cooperation;

2) Calculating the rates _RA and RB obtained by primary users A and _B through cognitive user cooperation;

3) If R _A ≥ R _AT and R _B ≥ R _BT , the primary user will allocate part of the time to the acquaintance user, authorize it to access its own spectrum, and use a part of the bandwidth after the acquaintance user accesses the spectrum of the primary system Forward the main user's information and use the remaining bandwidth to send its own information; otherwise, the main user continues to send its own information through direct transmission;

The problem of joint allocation of time and bandwidth between primary and cognitive users is modeled as:

\underset{T T,, B B}{m m a a x x} {R R}_{S S} - - - - - - ((11))

The following conditions

\{\begin{matrix} {R R}_{A A} &GreaterEqual; &Greater Equal; {R R}_{A A T T} \\ {R R}_{B B} &GreaterEqual; &Greater Equal; {R R}_{B B T T} \\ 00 < < α α + + β β < < 11 \\ 00 < < n no + + m m < < 11 \\ 00 < < α α < < 11 \\ 00 < < β β < < 11 \\ 00 < < m m < < 11 \\ 00 < < n no < < 11 \end{matrix} - - - - - - ((22))

where R _AT and R _BT represent the target rates of primary users A and B respectively, T={m,n}, B={α,β}, m and n represent primary users A and B in the first time slot and the first time slot respectively α and β respectively represent the bandwidth used by the cognitive user to help the primary user A and B forward information in the third time slot, and _RA , _RB and _RS represent the cognitive user’s receiving time. After entering the primary user spectrum, the rates obtained by primary user A, primary user B, and cognitive user S are:

R _A =min{R _AS , _RSB }(3)

R _B =min{R _BS ,R _SA }(4)

{R R}_{S S} = = ((11 - - m m - - n no)) ((11 - - α α - - β β)) {Wlog wlog}_{22} ((11 + + \frac{{P P}_{S S} {γ γ}_{S S D D.}}{33 {σ σ}^{22}})) - - - - - - ((55))

Among them, PS represents the transmit power of cognitive user _S , γ _SD represents the channel gain of the link from the cognitive user sending end to the cognitive user receiving end, σ ² represents the noise power spectral density, R _AS and _RSB represent the primary user The rates obtained by A in the first and second slots:

{R R}_{A A S S} = = {mWlog wxya}_{22} ((11 + + \frac{{P P}_{A A} {γ γ}_{A A S S}}{{σ σ}^{22}})) - - - - - - ((66))

{R R}_{S S B B} = = \{\begin{matrix} [[m m - - ((11 - - m m - - n no)) α α]] {R R}_{A A 11} + + ((11 - - m m - - n no)) {αR αR}_{A A 22} & m m &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) α α \\ [[((11 - - m m - - n no)) α α - - m m]] {R R}_{A A 33} + + {mR mR}_{A A 22} & m m < < ((11 - - m m - - n no)) α α \end{matrix} - - - - - - ((77))

in,

R_{A 1} = {wlog}_{2} (1 + \frac{P_{A} γ_{A B}}{σ^{2}}),

R_{A 2} = {wlog}_{2} (1 + \frac{P_{S} γ_{S B}}{3 σ^{2}} + \frac{P_{A} γ_{A B}}{σ^{2}}),

P _A represents the transmit power of the primary user A, γ _AS , γ _SB and γ _AB represent the channel gain of the link from the primary user A to the cognitive user sender, the channel gain of the link from the cognitive user sender to the primary user B, and The channel gain of the link from primary user A to primary user B, R _BS and R _SA represent the rate obtained by primary user B in the first and second time slots respectively:

{R R}_{B B S S} = = {nWlog wxya}_{22} ((11 + + \frac{{P P}_{B B} {γ γ}_{B B S S}}{{σ σ}^{22}})) - - - - - - ((88))

{R R}_{S S A A} = = \{\begin{matrix} [[n no - - ((11 - - m m - - n no)) β β]] {R R}_{B B 11} + + ((11 - - m m - - n no)) {βR βR}_{B B 22} & n no &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) β β \\ [[((11 - - m m - - n no)) β β - - n no]] {R R}_{B B 33} + + {nR nR}_{B B 22} & n no < < ((11 - - m m - - n no)) β β \end{matrix} - - - - - - ((99))

in

R_{B 1} = {wlog}_{2} (1 + \frac{P_{B} γ_{B A}}{σ^{2}}),

R_{B 2} = {wlog}_{2} (1 + \frac{P_{S} γ_{S A}}{3 σ^{2}} + \frac{P_{B} γ_{B A}}{σ^{2}}),

P _B represents the transmit power of the primary user B, γ _BS , γ _SA and γ _BA represent the channel gain of the link from the primary user B to the cognitive user sender, the channel gain of the link from the cognitive user sender to the primary user A and Channel gain of the link from primary user B to primary user A;

The above optimal time allocation is obtained by mathematical optimization method:

{m m}^{* *} = = \frac{{R R}_{A A T T}}{{Wlog wlog}_{22} ((11 + + \frac{{P P}_{A A} {γ γ}_{A A S S}}{{σ σ}^{22}}))} - - - - - - ((1010))

{n no}^{* *} = = \frac{{R R}_{B B T T}}{{Wlog wlog}_{22} ((11 + + \frac{{P P}_{B B} {γ γ}_{B B S S}}{{σ σ}^{22}}))} - - - - - - ((1111))

According to the different values of _RSB and _RSA , the optimal bandwidth allocation in 4 different situations is obtained:

①When

\{\begin{matrix} m^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) α \\ {no}^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) β \end{matrix}

hour,

{{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} {R R}_{A A 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{A A 22} - - {R R}_{A A 11}))} \\ β β = = \frac{{R R}_{A A B B} - - {n no}^{* *} {R R}_{B B 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{B B 22} - - {R R}_{B B 11}))} \end{matrix} - - - - - - ((1212))

② when

\{\begin{matrix} m^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) α \\ {no}^{*} < (1 - m^{*} - {no}^{*}) β \end{matrix}

hour,

{{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} {R R}_{A A 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{A A 22} - - {R R}_{A A 11}))} \\ β β = = \frac{{R R}_{A A B B} - - {n no}^{* *} (({R R}_{B B 22} - - {R R}_{B B 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{B B 33}} \end{matrix} - - - - - - ((1313))

③When

\{\begin{matrix} m^{*} < (1 - m^{*} - {no}^{*}) α \\ {no}^{*} &Greater Equal; (1 - m^{*} - {no}^{*}) β \end{matrix}

hour,

{{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} (({R R}_{A A 22} - - {R R}_{A A 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{A A 33}} \\ β β = = \frac{{R R}_{B B T T} - - {n no}^{* *} {R R}_{B B 11}}{((11 - - {m m}^{* *} - - {n no}^{* *})) (({R R}_{B B 22} - - {R R}_{B B 11}))} \end{matrix} - - - - - - ((1212))

④ when

\{\begin{matrix} m^{*} < (1 - m^{*} - {no}^{*}) α \\ {no}^{*} < (1 - m^{*} - {no}^{*}) β \end{matrix}

hour,

{{\begin{matrix} α α = = \frac{{R R}_{A A T T} - - {m m}^{* *} (({R R}_{A A 22} - - {R R}_{A A 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{A A 33}} \\ β β = = \frac{{R R}_{B B T T} - - {n no}^{* *} (({R R}_{B B 22} - - {R R}_{B B 33}))}{((11 - - {m m}^{* *} - - {n no}^{* *})) {R R}_{B B 33}} \end{matrix} - - - - - - ((1515)) . .

2. The cooperative anti-jamming spectrum access method based on joint optimization of time and bandwidth as claimed in claim 1, characterized in that: in said step 2), the cognitive user decodes and forwards the cooperative mode access authorization through three time slots user's spectrum;

In the first time slot, the primary user A uses m time slots to send information to the cognitive user S, and the transmission rate of the A→S link is:

{R R}_{A A S S} = = {mWlog wxya}_{22} ((11 + + \frac{{P P}_{A A} {γ γ}_{A A S S}}{{σ σ}^{22}})) - - - - - - ((66))

In the second time slot, the primary user B uses n time slots to send information to the cognitive user S, and the transmission rate of the B→S link is:

{R R}_{B B S S} = = {nWlog wxya}_{22} ((11 + + \frac{{P P}_{B B} {γ γ}_{B B S S}}{{σ σ}^{22}})) - - - - - - ((88))

In the third time slot, the cognitive user _S uses the αW bandwidth and the power of PS /3 to help the primary user A to transmit information, and uses the _βW bandwidth and the power of PS /3 to help the primary user B transmit information. After the maximum ratio Combined, the transmission rates of the S→B link and the S→A link are:

{R R}_{S S B B} = = \{\begin{matrix} [[m m - - ((11 - - m m - - n no)) α α]] {R R}_{A A 11} + + ((11 - - m m - - n no)) {αR αR}_{A A 22} & m m &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) α α \\ [[((11 - - m m - - n no)) α α - - m m]] {R R}_{A A 33} + + {mR mR}_{A A 22} & m m < < ((11 - - m m - - n no)) α α \end{matrix} - - - - - - ((99))

{R R}_{S S A A} = = \{\begin{matrix} [[n no - - ((11 - - m m - - n no)) β β]] {R R}_{B B 11} + + ((11 - - m m - - n no)) {βR βR}_{B B 22} & n no &GreaterEqual; &Greater Equal; ((11 - - m m - - n no)) β β \\ [[((11 - - m m - - n no)) β β - - n no]] {R R}_{B B 33} + + {nR nR}_{B B 22} & n no < < ((11 - - m m - - n no)) β β \end{matrix} - - - - - - ((77))

Therefore, the rates obtained by primary users A and B with the help of cognitive user S through three time slots are:

R _A =min{R _AS , _RSB }(3)

R _B =min{R _BS ,R _SA }(4)

At the same time, cognitive users use the remaining (1-α-β)W bandwidth and (1-m-n) time slots to send their own information, so the rate obtained by cognitive users is:

{R R}_{S S} = = ((11 - - m m - - n no)) ((11 - - α α - - β β)) {Wlog wlog}_{22} ((11 + + \frac{{P P}_{S S} {γ γ}_{S S D D.}}{33 {σ σ}^{22}})) - - - - - - ((55)) . .