OPTICAL DISTRIBUTED ANTENNA SYSTEM
First Claim
1. An optical distributed antenna system (DAS) comprising:
- a) a head-end (HE) unit used to transmit downlink (DL) a modulated DL λ
0 optical signal and a plurality N of continuous waves (CWs), each CW having a different wavelength λ
N; and
b) a plurality of remote units (RU), wherein each RU includes a reflective electro-absorption transceiver (REAT) which has a single optical interface and a single RF port, the REAT used to detect and convert the λ
0 optical signal into a RF signal and to reflect and modulate one CW with wavelength λ
N for uplink transmission to the HE unit.
0 Assignments
0 Petitions
Accused Products
Abstract
Optical distributed antenna systems comprising a head-end unit adapted to transmit downlink a modulated optical signal with wavelength λ0 and N un-modulated optical signals with wavelength λN and N remote units (RU) and including at least one circulator. In some embodiments, an HE unit includes an arrangement of a single circulator coupled to a single detector, the arrangement preventing beating. In some embodiments, a RU includes a reflective electro-absorption transceiver (REAT) which includes a single optical interface and a single RF port. The REAT detects the optical signal with λ0 and converts it into a RF signal, and reflects an un-modulated optical signal with wavelength λN to provide a modulated uplink optical signal. In some embodiments, a RU is configured as an optical antenna unit. In some embodiments, a plurality of RUs is combined with passive optical distribution units to provide hierarchical DAS architectures.
-
Citations
20 Claims
-
1. An optical distributed antenna system (DAS) comprising:
-
a) a head-end (HE) unit used to transmit downlink (DL) a modulated DL λ
0 optical signal and a plurality N of continuous waves (CWs), each CW having a different wavelength λ
N; andb) a plurality of remote units (RU), wherein each RU includes a reflective electro-absorption transceiver (REAT) which has a single optical interface and a single RF port, the REAT used to detect and convert the λ
0 optical signal into a RF signal and to reflect and modulate one CW with wavelength λ
N for uplink transmission to the HE unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. An optical distributed antenna system (DAS) comprising:
-
a) a head-end (HE) unit used to transmit downlink a modulated λ
0 optical signal and a plurality N of continuous waves (CWs) with respectively different wavelengths λ
N, the HE unit including an arrangement of a single detector and a circulator for a bunch of uplink signals with wavelength λ
1 to λ
N, wherein the arrangement prevents beating per bunch; andb) a plurality of remote units (RU), each RU including a reflective electro-absorption transceiver (REAT) used to detect and convert the λ
0 optical signal into a RF signal and to reflect and modulate one CW with wavelength λ
N for uplink transmission to the HE unit. - View Dependent Claims (15, 16, 17, 18, 20)
-
-
19. A method for communications in an optical distributed antenna system (DAS) comprising the steps of:
-
a) at a head-end (HE) unit, transmitting downlink to a remote unit (RU) a modulated optical signal with wavelength λ
0 and a continuous wave (CW) with wavelength λ
N;b) at the RU, using a reflective electro-absorption transceiver (REAT) with a single optical interface and a single RF port to convert the modulated optical signal with wavelength λ
0 into a downlink RF signal and to reflect and modulate the CW with wavelength λ
N to obtain a reflected modulated optical signal with wavelength λ
N; andc) transmitting the reflected optical signal with wavelength λ
N uplink to the HE unit.
-
Specification