METHODS TO REDUCE FRONTHAUL COMPLEXITY FOR SINGLE FREQUENCY NETWORK (SFN) IN AN OPEN RADIO ACCESS NETWORK (O-RAN)
An Open Radio Access Network (O-RAN) system including a single frequency network (SFN) for handling signal transmissions involving a user equipment (UE) is provided, which system includes: a plurality of O-RAN radio units (O-RUs) configured to simultaneously send the same signal over the same frequency channel; and an O-RAN distributed unit (O-DU). The system is configured to filter out at least one of uplink (UL) and downlink (DL) signals associated with at least one of the plurality of O-RUs in the SFN based on one of signal power or signal-to-noise ratio (SNR). Signal paths of the O-RUs toward the O-DU are linked directly to the O-DU, and each of the O-RUs filters one of UL and DL signals based on a comparison to a predetermined signal power or SNR threshold. The O-DU controls DL transmission to only use the O-RUs whose UL signals were above the predetermined threshold.
1 . An Open Radio Access Network (O-RAN) system including a single frequency network (SFN) for handling signal transmissions involving a user equipment (UE), comprising:
a plurality of O-RAN radio units (O-RUs) configured to simultaneously send the same signal over the same frequency channel; and
an O-RAN distributed unit (O-DU);
wherein the system is configured to filter out at least one of uplink (UL) and downlink (DL) signals associated with at least one of the plurality of O-RUs in the SFN based on one of signal power or signal-to-noise ratio (SNR).
2 . The system according to claim 1 , wherein signal paths of the O-RUs toward the O-DU are linked directly to the O-DU.
3 . The system according to claim 2 , wherein each of the O-RUs filters one of UL and DL signals based on a comparison to one of a predetermined signal power threshold or a predetermined SNR threshold.
4 . The system according to claim 3 , wherein the O-DU performs at least one of copying and combining the signals from different O-RUs in at least one of DL and UL.
5 . The system according to claim 3 , wherein the one of the predetermined signal power threshold or the predetermined SNR threshold is specified by the O-DU.
6 . The system according to claim 2 , wherein the O-RUs are configured to only send physical resource blocks (PRBs) having one of i) power above a specified threshold power, or ii) SNR above a specified threshold SNR.
7 . The system according to claim 1 , further comprising:
a fronthaul multiplexer (FHM) linking the O-RUs to the O-DU;
wherein the plurality of O-RUs all send UL data, and the FHM determines which UL data to use for combining based on one of a predetermined signal power threshold or a predetermined SNR threshold.
8 . The system according to claim 2 , wherein, based on UL signals for the UE received at the O-DU, the O-DU controls DL transmission by transmitting DL signals for the UE only through the O-RUs for which the received UL signals for the UE were above one of a predetermined signal power threshold or a predetermined SNR threshold.
9 . The system according to claim 2 , wherein, based on UL signals for the UE received at the O-DU, the O-DU schedules DL transmission only for the O-RUs whose UL signals were above one of a predetermined signal power threshold or a predetermined SNR threshold.
10 . The system according to claim 3 , wherein the one of the predetermined signal power threshold or the predetermined SNR threshold is at least one of: i) statically determined based on at least one of the O-RAN parameters and the SFN parameters; ii) dynamically determined using machine learning; and iii) determined based on configured modulation scheme for the UE.
11 . A method of operating an Open Radio Access Network (O-RAN) system including a single frequency network (SFN) for handling signal transmissions involving a user equipment (UE), comprising:
providing a plurality of O-RAN radio units (O-RUs) configured to simultaneously send the same signal over the same frequency channel;
providing an O-RAN distributed unit (O-DU); and
configuring the system to filter out at least one of uplink (UL) and downlink (DL) signals associated with at least one of the plurality of O-RUs in the SFN based on one of signal power or signal-to-noise ratio (SNR).
12 . The method according to claim 11 , wherein signal paths of the O-RUs toward the O-DU are linked directly to the O-DU.
13 . The method according to claim 12 , wherein each of the O-RUs filters one of UL and DL signals based on a comparison to one of a predetermined signal power threshold or a predetermined SNR threshold.
14 . The method according to claim 13 , wherein the O-DU performs at least one of copying and combining the signals from different O-RUs in at least one of DL and UL.
15 . The method according to claim 13 , wherein the one of the predetermined signal power threshold or the predetermined SNR threshold is specified by the O-DU.
16 . The method according to claim 12 , wherein the O-RUs are configured to only send physical resource blocks (PRBs) having one of i) power above a specified threshold power, or ii) SNR above a specified threshold SNR.
17 . The method according to claim 11 , further comprising:
providing a fronthaul multiplexer (FHM) linking the O-RUs to the O-DU;
wherein the plurality of O-RUs all send UL data, and the FHM determines which UL data to use for combining based on one of a predetermined signal power threshold or a predetermined SNR threshold.
18 . The method according to claim 12 , wherein, based on UL signals for the UE received at the O-DU, the O-DU controls DL transmission by transmitting DL signals for the UE only through the O-RUs for which the received UL signals for the UE were above one of a predetermined signal power threshold or a predetermined SNR threshold.
19 . The method according to claim 12 , wherein, based on UL signals for the UE received at the O-DU, the O-DU schedules DL transmission only for the O-RUs whose UL signals were above one of a predetermined signal power threshold or a predetermined SNR threshold.
20 . The method according to claim 13 , wherein the one of the predetermined signal power threshold or the predetermined SNR threshold is at least one of: i) statically determined based on at least one of the O-RAN parameters and the SFN parameters; ii) dynamically determined using machine learning; and iii) determined based on configured modulation scheme for the UE.