An adaptive rate selecting algorithm based on vehicle safety communication

[0015] The adaptive rate selection algorithm based on vehicle safety communication of the present embodiment, described adaptive rate selection algorithm is realized through the following steps:

[0016] In the first step, all parameters are initialized, and the PLR AVG , PLR INT , and PLR FAD All assigned as 0, the optimal rate is set to the basic rate (3Mbps);

[0017] In the second step, according to the principle of channel symmetry, each node uses Sym2PLR locally for average packet loss PLR AVG estimate of

[0018] The third step is to use Dis2PLR to perform fading packet loss PLR according to the relative distance of each node calculated by the application layer FAD estimate of

[0019] In the fourth step, according to the packet loss rate calculated in the first two steps, the influence of interference on packet loss PLR is obtained INT ;

[0020] The fifth step, using fuzzy decision FuzzyRateSelection, according to PLR FAD and PLR INT Get the best rate BestBitRat

[0021] Different from the specific embodiment one, the adaptive rate selection algorithm based on vehicle safety communication in this embodiment, the PLR ​​described in step one AVG The acquisition process is that the vehicle nodes all send safety messages, and for the reference node, it can continuously receive safety messages from other nodes using PLR i0 , represents the downlink packet loss rate sent from node i to reference node 0, according to channel symmetry theory, PLR 0i and PLR i0 is strongly symmetrically correlated, that is, the PLR ​​calculated for long time sampling 0i Equal to PLR i0 , the reference node can be calculated by calculating the PLR i0 to estimate the PLR 0i ,have to:

[0022] Different from the specific embodiment one or two, the adaptive rate selection algorithm based on vehicle safety communication in this embodiment, the PLR ​​described in step one FAD The acquisition process is,

[0023] The influence of fading on the average packet loss can be obtained by averaging the packet loss caused by channel fading of all nodes within the safe distance of the reference node:

[0024]

[0025] PLR INT =PLR AVG -PLR FAD .