Multi-beam operation for random access transmission in a mobile radio communication network

1. A method for enabling network access in a radio communication network, the method comprising:

defining a plurality of beams, to cover a predetermined area, wherein each beam has a polarization or coverage area different from the other beams; and

transmitting simultaneously in the plurality of beams and over a plurality of sub-carriers an Orthogonal Frequency-Division Multiplexing (OFDM) modulated signal comprising control information for use in a network access procedure, wherein each of the plurality of beams is represented by at least one of the sub-carriers comprising the control information; and

upon failing to receive further control information for use in the network access procedure in a first transmission, receiving the further control information re-transmitted using a different beam direction while maintaining a same transmit power.

2. The method of claim 1 , wherein the further control information is transmitted based on a beam direction in which the control information is received.

3. The method of claim 1 , wherein the transmitting further comprises mapping each of the at least one sub-carriers to one beam of the plurality of beams, wherein each of the at least one sub-carrier comprises a pattern repeated over time.

4. The method of claim 1 , wherein the transmitting further comprises mapping the at least one sub-carriers to one beam of the plurality of beams, wherein the at least one sub-carrier further comprises a block of sub-carriers comprising a predetermined number of sub-carriers.

5. The method of claim 1 , wherein the transmitting further comprises transmitting simultaneously in the plurality of beams and over the plurality of sub-carriers the OFDM modulated signal that includes a beam identifier associated with the corresponding beam.

6. The method of claim 1 , wherein the transmitting further comprises transmitting simultaneously in the plurality of beams and over the plurality of sub-carriers the OFDM modulated signal that indicates a direction of each of the plurality of beams in reference to predefined resources.

7. The method of claim 6 , wherein the predefined resources include at least frequency and time.

8. The method of claim 1 , wherein the OFDM modulated signal comprises at least one of a Random Access Channel (RACH) preamble signal, a pilot signal, a broadcast signal and a synchronization signal.

9. A network node including:

a processor; and

a transceiver in communication with the processor and configured to:

transmit simultaneously in a plurality of beams and over a plurality of sub-carriers, an Orthogonal Frequency-Division Multiplexing Signal (OFDM) modulated signal comprising control information for use in a network access procedure, wherein each of the plurality of beams is represented by at least one of the sub-carriers comprising the control information and wherein the plurality of beams are defined to cover a predetermined area, wherein each beam has a polarization or coverage area that is different from the other beams; and

upon failing to receive further control information for use in the network access procedure in a first transmission, receive the further control information re-transmitted using a different beam direction while maintaining a same transmit power.

10. A computer program product for enabling network access in a radio communication network, the computer program product comprising:

a non-transitory computer-readable medium comprising a set of codes for causing a computer to:

transmit simultaneously in a plurality of beams and over a plurality of sub-carriers, an Orthogonal Frequency-Division Multiplexing Signal (OFDM) modulated signal comprising control information for use in a network access procedure, wherein each of the plurality of beams is represented by at least one of the sub-carriers comprising the control information and wherein the plurality of beams are defined to cover a predetermined area, such that each beam has a polarization or coverage area that is different from the other beams; and

upon failing to receive further control information for use in the network access procedure in a first transmission, receive the further control information re-transmitted using a different beam direction while maintaining a same transmit power.

11. A method for network access in a radio communication network, the method comprising:

receiving, from a network node, control information for use in a network access procedure, wherein the control information is transmitted, from the network node, simultaneously in a plurality of beams and over a plurality of sub-carriers in an Orthogonal Frequency-Division Multiplexing (OFDM) modulated signal; and

determining a beam direction used for transmitting the received control information based on one or more sub-carriers comprising the control information;

in response to determining the beam direction, transmitting, to the network node, further control information for use in the network access procedure; and

in response to the network node failing to receive the further control information, re-transmitting the further control information using a different beam direction while maintaining a same transmit power.

12. The method of claim 11 , wherein determining beam direction further comprises determining the beam direction used for transmitting the received control information based on a pre-defined mapping of one or more sub-carriers to beam directions for each of the plurality of beams in reference to predefined resources.

13. The method of claim 11 , further comprising, prior to receiving the control information, receiving pre-defined mapping of one or more of the plurality of sub-carriers to a beam direction for each of the plurality of beams.

14. The method of claim 11 , wherein the further control information that-indicates the determined beam direction.

15. The method of claim 14 , wherein transmitting the further control information further comprises transmitting the further control information in a plurality of short burst transmissions, each short burst transmission associated with at least one of the sub-carriers within the OFDM modulated signal.

16. The method of claim 15 , wherein the network node measures a power of each short burst transmission, identifies a short burst transmission with a strongest power and transmits the beam identity information associated with the identified short burst transmission.

17. The method of claim 16 , further comprising receiving, from the network node, the beam identity information and using the beam identity information to select a beam direction for further transmissions.

18. The method of claim 11 , further comprising in response to receiving the control information, transmitting, to the network node, further control information for use in the network access procedure, wherein the further control information is transmitted in a same beam direction as the determined beam direction.

19. A network node including:

a processor; and

a transceiver in communication with the processor and configured to receive, from a second network node, control information for use in a network access procedure, wherein the control information is transmitted, from the second network node, simultaneously in a plurality of beams and over a plurality of sub-carriers in an Orthogonal Frequency-Division Multiplexing (OFDM) modulated signal,

wherein the processor is configured to determine a beam direction used for transmitting the received control information based on one or more sub-carriers comprising the control information,

wherein the transceiver is further configured to transmit, to the second network node, further control information for use in the network access procedure, and

wherein, in response the second network node failing to receive the further control information, the transceiver is configured to re-transmit the further control information using a different beam direction while maintaining a same transmit power.