A vehicle-mounted device stores delay time information of a first set and a second set. The first set includes a first transmission delay time from an external portion to a measurement reference position at a data reception time, and a second transmission delay time from an external portion to a measurement reference position at a data reception time in another device. The second set includes a third transmission delay time from a measurement reference position to an external portion at a data transmission time, and a fourth transmission delay time from a measurement reference position to an external portion at a data transmission time in the other device. A propagation delay time between the devices is measured by time synchronization information to and from the other device, the measured propagation delay time is corrected based on the stored delay time information, and time synchronization between the devices is performed.

Processing a digital bit stream and systems for implementing the methods are provided. The method includes dividing the digital bit stream into a plurality of data packets. In a first processing block performing a carrier recovery error calculation on a first portion of the plurality of data packets, comprising preforming a first phase locked loop (PLL) function on decimated data of the data packets and performing a carrier recovery operation on the first portion of the plurality of data packets. In a second processing block, in parallel with the processing of the first portion of the plurality of packets, performing the carrier recovery error calculation on a second portion of the plurality of data packets, comprising preforming the first PLL function on decimated data of the data packets and performing the carrier recovery operation on second portion of the plurality of data packets.

Disclosed herein are a Bluetooth signal receiving device and a Bluetooth Smart receiving method. The Bluetooth signal receiving device includes a frequency shift demodulator circuit, a sampler circuit, a training bit pattern discriminator circuit, and a symbol timing offset compensation circuit. The frequency shift demodulator circuit generates a baseband signal by performing frequency shift modulation on a received signal. The sampler circuit samples the baseband signal based on a symbol timing, and generates a plurality of series of bit streams based on sampled values. The training bit pattern discriminator circuit determines whether the plurality of series of bit streams generated by the sampler circuit satisfies a training bit pattern condition. The symbol timing offset compensation circuit compensates the symbol timing of the baseband signal based on a measured error metric as an effective error metric if the plurality of series of bit streams satisfies the training bit pattern condition.

A vehicle-mounted device stores delay time information of a first set and a second set. The first set includes a first transmission delay time from an external portion to a measurement reference position at a data reception time, and a second transmission delay time from an external portion to a measurement reference position at a data reception time in another device. The second set includes a third transmission delay time from a measurement reference position to an external portion at a data transmission time, and a fourth transmission delay time from a measurement reference position to an external portion at a data transmission time in the other device. A propagation delay time between the devices is measured by time synchronization information to and from the other device, the measured propagation delay time is corrected based on the stored delay time information, and time synchronization between the devices is performed.