Corning Optical Communications Wireless Ltd

Corning Mobileaccess Ltd.

Yair Oren

Ofer Saban

Igor Berlin

Isaac Shapira

Rami Reuven

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.

Distributed antenna system for MIMO technologies

A method and system for supporting MIMO 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.

The present invention is directed to improvements for distributed antenna systems and more particularly to methods and systems for improving uplink communications. In one embodiment, Aggregation Point Noise Blocking provides for blocking or filtering the noise contributed by one or more of the branches coupled to an aggregation point that are not carrying the signal from a particular terminal. Signal activity from a given terminal on a particular branch can be identified and that information can be used to selectively block or filter the signal noise contributed by the other branches to an aggregation point. The selective blocking or filtering can also include an attenuation function to attenuate the signal and provide dynamic range smoothing. In another embodiment the signal can be regenerated to produce a signal that has a restored or very high SNR. An uplink regeneration block can be provided which demodulates the uplink signal to recover the transmitted information and then re-modulates the transmitted information to regenerate a signal at a restored or very high SNR.

Method and system for improving uplink performance

The invention is directed to a method and system for supporting MIMO 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.

The invention is directed to a method and system for equalizing the signal losses over cable runs in a Distributed Antenna System (DAS). In a DAS, two or more antennae are connected to the system by cable runs that can vary widely in length. As a result, the signal loss over a given cable run can also vary widely which can impact the design and deployment of the DAS and reduce antenna spacing. In addition, for a broadband DAS that supports many frequency bands or ranges using a common antenna unit, the signal losses vary with respect to frequency further making it difficult to equalize the cable losses. According to one embodiment of the invention, the method and system provide for measuring and adjusting the signal losses of each cable run to be a predefined value. According to another embodiment of the invention, the DAS can include a hybrid passive-active antenna unit which includes a frequency multiplexer that separates the signal into frequency bands or ranges that are connected to an antenna element associated with a particular frequency band or range. Where a single frequency band needs to be amplified (or attenuated), a single band amplification block (SBAB) can be inserted in the connection between the frequency multiplexer and the antenna element to amplify (or attenuate) the desired frequency band. Where more than one frequency band need to be amplified (or attenuated), a multiband amplification block (MBAB) can be inserted in the connection between the frequency multiplexer and the appropriate antenna element to amplify (or attenuate) the desired frequency bands.

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Washington, DC, United States of America

Yair Oren