Synchronization in a Beamforming System
A beamforming system synchronization architecture is proposed to allow a receiving device to synchronize to a transmitting device in time, frequency, and spatial domain in the most challenging situation with very high pathloss. A periodically configured time-frequency resource blocks in which the transmitting device uses the same beamforming weights for its control beam transmission to the receiving device. A pilot signal for each of the control beams is transmitted in each of the periodically configured time-frequency resource blocks. The same synchronization signal can be used for all stages of synchronization including initial coarse synchronization, device and beam identification, and channel estimation for data demodulation.
1 . A method comprising:
receiving a set of control beam transmissions from a base station (eNB) by a user equipment (UE) in a beamforming mobile communication network, wherein each control beam comprises a set of downlink (DL) control resource blocks, a set of uplink (UL) control resource blocks, associated with a set of eNB beamforming weights;
switching to different sets of UE beamforming weights for receiving the set of control beam transmissions at different control cycles;
determining a corresponding set of UE beamforming weights to be paired with each of the control beam; and
selecting a control beam for receiving cell and beam identification information from the eNB by using the determined corresponding UE beamforming weights paired with the selected control beam.
2 . The method of claim 1 , wherein a collection of the eNB beamforming weights of the control beams creates a radiation pattern covering an entire service area of a cell provided by the base station.
3 . The method of claim 1 , wherein the DL control resource blocks comprise a pilot part and a data part, and wherein the UE receives the cell and beam identification information from the pilot part.
4 . The method of claim 3 , wherein the pilot part comprises M pilot structures and each pilot structure comprises L OFDM symbols in time domain and R subcarriers in frequency domain, wherein the pilot symbols are inserted once every K subcarriers for R times in each OFDM symbol such that the same pilot symbols are repeated for L times in each pilot structure, and wherein M, L, R, and K are positive integers.
5 . The method of claim 1 , wherein the DL control resource blocks comprises a pilot part and a data part, and wherein the UE receives control and traffic information from the data part.
6 . The method of claim 1 , wherein the UE performs time, frequency, and spatial synchronization with the base station via the DL control resource blocks of the selected control beam.
7 . The method of claim 1 , wherein the UL control resource blocks comprise a pilot part and a data part, and wherein the UE transmits UE identification information via the pilot part.
8 . The method of claim 1 , wherein the UL control resource blocks comprise a pilot part and a data part, and wherein the UE transmits UE-specific control and traffic data via the data part.
9 . The method of claim 1 , wherein the UE performs random access with the base station via the UL control resource blocks of the selected control beam.
10 . The method of claim 1 , wherein the control beams are configured having periodically occurred control cycles.
11 . A User Equipment (UE) comprising:
a radio frequency (RF) receiver that receives a set of control beam transmissions from a base station (eNB) by a user equipment (UE) in a beamforming mobile communication network, wherein each control beam comprises a set of downlink (DL) control resource blocks, a set of uplink (UL) control resource blocks, associated with a set of eNB beamforming weights;
a plurality of antennas that applies different sets of UE beamforming weights for receiving the set of control beam transmissions at different control cycles;
a processing circuit that determines a corresponding set of UE beamforming weights to be paired with each of the control beam; and
a beam selection circuit that selects a control beam for receiving cell and beam identification information from the eNB by using the determined corresponding UE beamforming weights paired with the selected control beam.
12 . The UE of claim 11 , wherein a collection of the eNB beamforming weights of the control beams creates a radiation pattern covering an entire service area of a cell provided by the base station.
15 . The UE of claim 11 , wherein the DL control resource blocks comprise a pilot part and a data part, and wherein the UE receives the cell and beam identification information from the pilot part.
14 . The UE of claim 13 , wherein the pilot part comprises M pilot structures and each pilot structure comprises L OFDM symbols in time domain and R subcarriers in frequency domain, wherein the pilot symbols are inserted once every K subcarriers for R times in each OFDM symbol such that the same pilot symbols are repeated for L times in each pilot structure, and wherein M, L, R, and K are positive integers.
15 . The UE of claim 11 , wherein the DL control resource blocks comprises a pilot part and a data part, and wherein the UE receives control and traffic information from the data part.
16 . The UE of claim 11 , wherein the UE performs time, frequency, and spatial synchronization with the base station via the DL control resource blocks of the selected control beam.
17 . The UE of claim 11 , wherein the UL control resource blocks comprise a pilot part and a data part, and wherein the UE transmits UE identification information via the pilot part.
18 . The UE of claim 11 , wherein the UL control resource blocks comprise a pilot part and a data part, and wherein the UE transmits UE-specific control and traffic data via the data part.
19 . The UE of claim 11 , wherein the UE performs random access with the base station via the UL control resource blocks of the selected control beam.
20 . The UE of claim 11 , wherein the control beams are configured having periodically occurred control cycles.