Patent ID: 9094911
Filing Date: 2015-07-28
Classification: H04W

Abstract:
1. A data communication system comprising: a transmission apparatus for transmitting a frame in response to a transmission command supplied thereto, and a receiving apparatus for receiving said frame, said frame including a preamble, a start frame delimiter (SFD), and data in that order; wherein said receiving apparatus includes: a synchronization detection part which detects bit synchronization based on the preamble of the frame received by the receiving apparatus from the transmitting apparatus; a synchronization position information generating part which generates synchronization position information of a position of the bit synchronization, included in the frame received in the receiving apparatus, detected by the synchronization detection part, said synchronization position information generating part comprising a counter part to generate a bit number corresponding to a time period between a first time point at which the bit synchronization is detected by the synchronization detection part and a second time point at which the SFD of the frame is detected; a transmitting and receiving part which transmits a frame including said synchronization position information to said transmission apparatus; wherein said transmission apparatus includes: a preamble length calculating part which calculates a number of reduced bytes by subtracting a number of bits of the SFD from said bit number and dividing by the bit number of one byte, and calculates an optimal value of a length of the preamble by subtracting the number of reduced bytes from an initial preamble length; and a transmit command issuing part which supplies said transmit command of transmission of a frame including a preamble having a length based on the optimal value from the transmission apparatus to the receiving apparatus; and a transmitting and receiving part which adjusts the preamble length of a frame toward said optimal value and transmits the frame as a wireless signal.