Transmission method and related base station
The invention relates to transmission from a base station to a receiver, the base station comprising first radiating means arranged for transmitting according to an antenna pattern with respect to the receiver and further comprising second radiating means arranged for transmitting according to the same antenna pattern as the first radiating means with respect to the receiver, the transmissions of the first and second radiating means being time shifted by a determined duration.
1. A method of transmitting from a base station to a receiver, the base station comprising a first antenna assembly and a second antenna assembly, the method comprising:
transmitting, by the first antenna assembly having plural radiating elements, a signal according to an antenna pattern with respect to the receiver;
transmitting, by the second antenna assembly having plural radiating elements, the signal with a time delay according to the same antenna pattern as the first antenna assembly with respect to the receiver, wherein the signal and the signal with the time delay transmitted by the respective first and second antenna assemblies are time shifted with respect to each other by a determined duration, wherein the first and second antenna assemblies are distinctly polarized, so as to provide polarization diversity, and wherein the first polarization is at a value substantially equal to +45 degrees and the second polarization is at a value substantially equal to −45 degrees.
2. The method of claim 1 , wherein the first and second antenna are arranged to achieve optimal decorrelation though polarization diversity.
3. The method of claim 1 , wherein the signals are channel coded, interleaved, modulated and allocated to time slots intended for one or more receivers in a time division multiple access (TDMA) scheme.
4. The method of claim 1 , wherein said determined duration is set so that a correlation factor between transmissions of the first and second antenna assemblies is below a predetermined level.
5. The method of claim 1 , wherein said determined duration is set so that the inter-symbol interference between transmissions of the first and second antenna assemblies is below a predetermined level.
6. The method of claim 1 , wherein the radiating elements of each of the first and second antenna assemblies are arranged for transmitting signal components with respective phase shifts, the phase shifts being set so as to define a direction of said antenna pattern with respect to the receiver.
7. The method of claim 1 , wherein the radiating elements of each of the first and second antenna assemblies are arranged for transmitting signal components with respective amplitude weights, the amplitude weights being set so as to define a width of said antenna pattern with respect to the receiver.
8. The method of claim 1 , wherein the first and second antenna assemblies are spatially separated, so as to provide space diversity.
9. The method of claim 1 , wherein each radiating element of the first antenna assembly is coupled to a respective radiating element of the second antenna assembly, so as to form a cross dipole with orthogonal polarizations.
10. The method of claim 1 , wherein the base station is comprised in a digital radio communication system.
11. A base station comprising:
a first antenna assembly having plural radiating elements arranged for transmitting a signal according to an antenna pattern with respect to a receiver;
a second antenna assembly having plural radiating elements arranged for transmitting the signal with a time delay according to the same antenna pattern as the first antenna assembly with respect to the receiver, wherein the signal and the signal with the time delay transmitted by the respective first and second antenna assemblies are time shifted with respect to each other by a determined duration, wherein the first and second antenna assemblies are distinctly polarized, so as to provide polarization diversity, and wherein the first polarization is at a value substantially equal to +45 degrees and the second polarization is at a value substantially equal to −45 degrees.
12. The base station of claim 11 , wherein the first and second antenna are arranged to achieve optimal decorrelation though polarization diversity.
13. The base station of claim 11 , wherein the signals are channel coded, interleaved, modulated and allocated to time slots intended for one or more receivers in a time division multiple access (TDMA) scheme.
14. The base station of claim 11 , wherein the determined duration is set so that a correlation factor between transmissions of the first and second antenna assemblies is below a predetermined level.
15. The base station of claim 11 , wherein the determined duration is set so that the inter-symbol interference between transmissions of the first and second antenna assemblies is below a predetermined level.
16. The base station of claim 11 , wherein the radiating elements of each of the first and second antenna assemblies are arranged for transmitting signal components with respective phase shifts, the phase shifts being set so as to define a direction of said antenna pattern with respect to the receiver.
17. The base station of claim 11 , wherein the radiating elements of each of the first and second antenna assemblies are arranged for transmitting signal components with respective amplitude weights, the amplitude weights being set so as to define a width of said antenna pattern with respect to the receiver.
18. The base station of claim 11 , wherein the first and second antenna assemblies are spatially separated, so as to provide space diversity.
19. The base station of claim 11 , wherein each radiating element of the first antenna assembly is coupled to a respective radiating element of the second antenna assembly, so as to form a cross dipole with orthogonal polarizations.
20. The base station of claim 11 , wherein the base station is comprised in a digital radio communication system.