Distributed antenna system for MIMO technologies

摘要

A method and system for supporting M1MO technologies which can require the transport of multiple spatial streams on a traditional Distributed Antenna System (DAS). According to the invention, at one end of the DAS, each spatial stream is shifted in frequency to a pre-assigned band (such as a band at a frequency lower than the native frequency) that does not overlap the band assigned to other spatial streams (or the band of any other services being carried by the DAS). Each of the spatial streams can be combined and transmitted as a combined signal over a common coaxial cable. At the other “end” of the DAS, the different streams are shifted back to their original (overlapping) frequencies but retain their individual “identities” by being radiated through physically separate antenna elements.

主权项

1. An antenna unit for distributing downlink MIMO signals for at least one MIMO service in distributed antenna system (DAS) received over a single coaxial cable coupled to a single coaxial cable port, comprising:
a single coaxial cable port coupled to a single coaxial cable, the single coaxial cable port configured to receive non-overlapping frequency MIMO downlink signals of at least one MIMO service over the single coaxial cable; at least two antenna unit downlink frequency shifters configured to frequency shift the non-overlapping frequency MIMO downlink signals to native frequency MIMO downlink signals; and at least two downlink output ports configured to receive and couple the native frequency MIMO downlink signals to at least two MIMO antennas, the at least two MIMO antennas configured to transmit the native frequency MIMO downlink signals, wherein the at least two antenna unit downlink frequency shifters are each configured to frequency shift the non-overlapping frequency MIMO downlink signals in a frequency range of 320 MHz to 520 MHz to native frequency MIMO downlink signals.