Patent ID: 7541978

Claim:
An antenna-assisted two-point positioning system for positioning a mobile device, comprising: a first wireless communication module comprising M first antennas, the mobile device transmitting a first signal strength to the i-th first antenna for a first receive signal strength (RSS 1 ), M being an integer larger than or equal to 1, i being an integer between 1 and M; a second wireless communication module comprising N second antennas, the mobile device transmitting a second signal strength to the j-th second antenna for a second receive signal strength (RSS 2 ), the second wireless communication module cooperating with the first wireless communication module to determine a first position and a second position corresponding to the mobile device, N being an integer larger than or equal to 1, N being different from M, j being an integer between 1 and N; a storage module for storing M first antenna gain tables corresponding to the M first antennas and N second antenna gain tables corresponding to the N second antennas; and a processing module for judging whether an environmental interference factor is ignorable; when the environmental interference factor is ignorable, the processing module judging that the mobile device is located at the first or second position based on the first receive signal strength (RSS 1 ), the second receive signal strength (RSS 2 ), the i-th first antenna gain table and the j-th second antenna gain table; wherein based on a distance (d 1 ) between the mobile device and the first communication module, a distance (d 2 ) between the mobile device and the second communication module, and a distance between the first communication module and the second communication module, the processing module calculates a first angle, a second angle, a third angle and a fourth angle utilizing cosine theorem, wherein each of the M first antenna gain tables and each of the N second antenna gain tables respectively record a plurality of angles and a plurality of gains, and each gain is respectively corresponding to one of the angles, wherein the processing module obtains a first gain (G 1 ) corresponding to the first angle and a second gain (G 2 ) corresponding to the second angle based on the i-th first antenna gain table, and obtains a third gain (G 3 ) corresponding to the third angle and a fourth gain (G 4 ) corresponding to the fourth angle based on the j-th second antenna gain table, once at least one of the following inequalities is satisfied, the processing module judges that the environmental interference factor is ignorable:  K 1 - K 3 K 1 * 100 ⁢ % - RSS 1 - RSS 2 RSS 1 * 100 ⁢ %  ≦ a ⁢ ⁢ first ⁢ ⁢ predetermined ⁢ ⁢ value ; and inequality ⁢ ⁢ 1  K 2 - K 4 K 2 * 100 ⁢ % - RSS 1 - RSS 2 RSS 1 * 100 ⁢ %  ≦ the ⁢ ⁢ first ⁢ ⁢ predetermined ⁢ ⁢ value ; K 1 = G 1 d 1 2 , K 2 = G 2 d 1 2 , K 3 = G 3 d 2 2 ⁢ ⁢ and ⁢ ⁢ K 4 = G 4 d 2 2 . inequality ⁢ ⁢ 2