Mobile payment systems and mobile payment methods thereof

A mobile payment system, comprising a wearable device and a mobile device wirelessly connected to the wearable device, wherein the mobile device transmits a payment instruction to the wearable device, and the wearable device determines whether a user's identity information stored in the payment instruction is correct;

• when the wearable device determines the user's identity information is correct, the wearable device generates a payment-permitted instruction, and encrypts the payment-permitted instruction by a secret key;
• the payment-permitted instruction is configured to permit the mobile device to make a payment;
• and
• the wearable device further transmits the encrypted payment-permitted instruction to the mobile device, and the mobile device decrypts the encrypted payment-permitted instruction and determines whether the decrypted payment-permitted instruction is correct;
• when the decrypted payment-permitted instruction is correct, the mobile device makes a payment;
• wherein the mobile device comprises a first communication module and an ASK (Amplitude-shift keying) receiving module, and the wearable device comprises a second communication module and a carrier transmission module;
• the payment instruction is transmitted from the first communication module of the mobile device to the second communication module of the wearable device;
• and
• the encrypted payment-permitted instruction is transmitted from the carrier transmission module of the wearable device to the ASK receiving module of the mobile device.