Method and device for synchronizing data transfer devices
View Patent ↗A method and a device for synchronizing data-transmission devices, in which devices a data signal is transmitted in the form of a stream of data bursts between a first station and a second station. A reference signal is transmitted in connection with the specific data burst. In a first step, a first reference signal is sent from the second station to the first station. In a second step, a channel estimation is carried out in the first station based on the reference signal received from the second station. In a third step, the first station sends to the second station a data burst predistorted on the basis of the channel estimation. In a fourth step, the first station sends to the second station a second reference signal altered on the basis of the channel estimation. In a fifth step, the second station synchronizes the data burst on the basis of the second reference signal.
1. A method for synchronizing data-transmission devices, in which a data signal is transmitted as a stream of data bursts between a first station and a second station, and a first reference signal and a second reference signal are transmitted in connection with a specific one of the data bursts, the method comprising:
sending the first reference signal from the second station to the first station;
performing a channel estimation in the first station based on the first reference signal received from the second station;
causing the first station to send to the second station one of the data bursts predistorted on the basis of the channel estimation;
causing the first station to send to the second station the second reference signal altered on the basis of the channel estimation; and
causing the second station to synchronize the one of the data bursts on the basis of the second reference signal.
2. The method as recited in claim 1 , wherein:
the second station is one of a plurality of different second stations, and
the first reference signal and the second reference signal are sent for each second station.
3. The method as recited in claim 2 , further comprising:
phase-rotating the second reference signal, for a predistortion in the first station, in a negative direction by a phase angle of a strongest channel pulse-response component; and
advancing in time the second reference signal by a propagation time of the first reference signal.
4. The method as recited in claim 1 , wherein:
the first station is a base station, and
the second station is a mobile station of a TDD mobile radio communications system.
5. The method as recited in claim 1 , wherein each transmission is carried out using CDMA.
6. The method as recited in claim 1 , wherein a plurality of data streams is transmitted simultaneously according to CDMA.
7. The method as recited in claim 1 , wherein each data burst includes at least two data blocks between which a block is arranged that is used for one of the first reference signal and the second reference signal.
8. A device for synchronizing data-transmission devices, wherein a data signal is transmitted as a stream of data bursts between a first station and a second station, and a first reference signal and a second reference signal are transmitted in connection with a specific one of the data bursts, the device comprising:
an arrangement configured to send the first reference signal from the second station to the first station;
an arrangement configured to perform a channel estimation in the first station based on the first reference signal received from the second station;
a data burst modification device, provided in the first station, adapted for causing the first station to send to the second station one of the data bursts predistorted on the basis of the channel estimation;
a reference-signal modification device, provided in the first station, adapted for modifying the second reference signal according to a result of a channel estimation, and for causing the first station to send to the second station the modified second reference signal; and
a synchronization device, provided in the second station, adapted for synchronizing the one of the data bursts according to the modified second reference signal received from the first station.
9. The device as recited in claim 8 , wherein:
the second station is one of a plurality of different second stations, and
the first reference signal and the second reference signal are sent for each second station.
10. The device as recited in claim 8 , wherein the modification of the second reference signal includes modifying a transmission time and a transmission phase of the second reference signal.
11. The device as recited in claim 10 , wherein:
the transmission time modification of the second reference signal includes advancing in time the second reference signal by a propagation time of the first reference signal; and
the transmission phase modification of the second reference signal includes phase-rotating the second reference signal, for a predistortion in the first station, in a negative direction by a phase angle of a strongest channel pulse-response component.
12. The device as recited in claim 8 , wherein:
the first station is a base station; and
the second station is a mobile station of a TDD mobile radio communications system.