Patent Application
20170079040
This application claims priority to Indian Patent Application number 4848/CHE/2015 filed on Sep. 11, 2015, the complete disclosure of which, in its entirely, is herein incorporated by reference.
Technical Field
The embodiments herein generally relate to cellular networks, and more particularly, to systems and methods for improving the coverage and capacity of cellular networks using relay nodes.
Description of the Related Art
Pursuant to an exemplary scenario, coverage of cellular systems may be improved by using relay nodes that can augment capacity or coverage of a cellular network. A typical cellular ecosystem consists of one or more base stations transmitting data on a downlink resource and receiving data on an uplink resource and a user equipment receiving on the downlink resource and transmitting on the uplink resource. The uplink and downlink resources may be operating at two different frequency allocations in the case of a Frequency Division Duplexing and at two different time intervals in the case of a Time Division Duplexing. Typically relaying may be performed through an out-band relaying or an in-band replaying. In out-band relaying, relaying may be performed using two different pairs of resources that are orthogonal to one another. In in-band relaying, relaying may be performed using one pair of resources. Typically, the in-band relaying does not require additional spectral resources to be acquired and is of considerable interest.
The first frequency link 102A is carried on the first frequency carrier 114A from the first uplink transmitter 214 to the first uplink receiver 210. The second frequency link 102B is carried on the second frequency carrier 114B from the first downlink transmitter 224 to the first downlink receiver 226. The third frequency link 102C is carried on the first frequency carrier 114A from the second uplink transmitter 218 to the second uplink receiver 216. The fourth frequency link 102D is carried on the second frequency carrier 114B from the second downlink transmitter 228 to the second downlink receiver 230. The fifth frequency link 102E is carried on the first frequency carrier 114A from the third uplink transmitter 222 to the third uplink receiver 220. The sixth frequency link 102F is carried on the second frequency carrier 114B from the third downlink transmitter 232 to the third downlink receiver 234.
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This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is to be intended to be used as an aid in determining the scope of the claimed subject matter.
In one aspect, a single-hop relay cellular system, includes a plurality of uplink receivers that includes at least a first uplink receiver and a second uplink receiver, a plurality of uplink transmitters that include at least a first uplink transmitter and a second uplink transmitter, wherein a first frequency link is carried on a first frequency carrier from the first uplink transmitter to the first uplink receiver. A third frequency link is carried on a second frequency carrier from the second uplink transmitter to the second uplink receiver, a plurality of downlink receivers that includes a first downlink receiver and a second downlink receiver, a plurality of downlink transmitters that includes a first downlink transmitter and a second downlink transmitter. A second frequency link is carried on the second frequency carrier from the first downlink transmitter to the first downlink receiver. A fourth frequency link is carried on the first frequency carrier from the second downlink transmitter to the second downlink receiver, a relay base station, which is configured to interchange a frequency of operation between the first frequency carrier and the second frequency carrier for uplink transmission and downlink transmission. The first frequency carrier enables a frequency division mode of operation of the cellular system for uplink operation of the single-hop cellular system, and the second frequency carrier enables the frequency division mode of operation of the single-hop cellular system for downlink operation, and an access base station, which is coupled to a user equipment base station through the relay base station.
In another aspect, a multi-hop relay cellular system, includes a plurality of uplink receivers that includes at least a first uplink receiver, a second uplink receiver, and a third uplink receiver, a plurality of uplink transmitters that include at least a first uplink transmitter, a second uplink transmitter, and a third uplink transmitter, a plurality of downlink receivers that includes at least a first downlink receiver, a second downlink receiver, and a third downlink receiver, a plurality of downlink transmitters that include at least a first downlink transmitter, a second downlink transmitter, and a third downlink transmitter. A first frequency link is carried on a first frequency carrier from the first uplink transmitter to the first uplink receiver, a second frequency link is carried on a second frequency carrier from the first downlink transmitter to the first downlink receiver, a fourth frequency link is carried on the first frequency carrier from the second downlink transmitter to the second downlink receiver, a third frequency link is carried on the second frequency carrier from the second uplink transmitter to the second uplink receiver, a fifth frequency link is carried on the first frequency carrier from the third uplink transmitter to the third uplink receiver, a sixth frequency link is carried on the second frequency carrier from the third downlink transmitter to the third downlink receiver, and a first relay base station and a second relay base station, the first relay base station and the second relay base station are configured to interchange a frequency of operation between the first frequency carrier and the second frequency carrier for uplink transmission and downlink transmission.
In yet another aspect, a method for relaying in a single-hop or multi-hop relay cellular system by interchanging frequency of operation between backhaul link and access link. The method includes following steps of (a) performing a reception operation in said uplink on the first frequency carrier from the first relay base station to an access base station through a first frequency link, while simultaneously performing, a transmission operation in the downlink on the second frequency carrier from an access base station to the first relay base station through a second frequency link; and (b) performing a reception operation in an uplink on a second frequency carrier from a user equipment (UE) or a second relay base station to a first relay base station through a third frequency link, while simultaneously performing a transmission operation in a downlink on the first frequency carrier from a first relay base station to a user equipment (UE) or a second relay base station through a fourth frequency link.
Embodiments of the present disclosure substantially eliminate or at least partially address the aforementioned problems in the prior art, and provide a mechanism for performing transmission and reception operations on different frequency carriers.
Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments construed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated using identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is point
The following detailed description illustrates embodiments of the present disclosure and ways in which they may be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
In one aspect, a single-hop relay cellular system, includes a plurality of uplink receivers that includes at least a first uplink receiver and a second uplink receiver, a plurality of uplink transmitters that include at least a first uplink transmitter and a second uplink transmitter, wherein a first frequency link is carried on a first frequency carrier from the first uplink transmitter to the first uplink receiver. A third frequency link is carried on a second frequency carrier from the second uplink transmitter to the second uplink receiver, a plurality of downlink receivers that includes a first downlink receiver and a second downlink receiver, a plurality of downlink transmitters that includes a first downlink transmitter and a second downlink transmitter. A second frequency link is carried on the second frequency carrier from the first downlink transmitter to the first downlink receiver. A fourth frequency link is carried on the first frequency carrier from the second downlink transmitter to the second downlink receiver, a relay base station, which is configured to interchange a frequency of operation between the first frequency carrier and the second frequency carrier for uplink transmission and downlink transmission. The first frequency carrier enables a frequency division mode of operation of the cellular system for uplink operation of the single-hop cellular system, and the second frequency carrier enables the frequency division mode of operation of the single-hop cellular system for downlink operation, and an access base station, which is coupled to a user equipment base station through the relay base station.
In an embodiment, the single-hop relay cellular system as claimed in claim 1, the relay base station performs a reception of the second frequency link and the reception of the third frequency link on the first frequency carrier, and performs a transmission of the first frequency link on the second frequency carrier and the transmission of a fourth frequency on a third frequency carrier.
In another embodiment, the single-hop relay cellular system as claimed in claim 1, the relay base station performs the transmission of the first frequency link and the transmission of the fourth frequency link on the first frequency carrier, and performs the reception of the second frequency link on the second frequency carrier and the reception of a third frequency on the third frequency carrier.
In yet another embodiment, the single-hop relay cellular system as claimed in claim 1, allocating the first frequency carrier and the second frequency carrier is selected from at least one of (i) no overlap implementation of the first frequency carrier and the second frequency carrier, or (ii) partial overlap implementation of the first frequency carrier and the second frequency carrier, or (iii) complete overlap of the first frequency carrier and the second frequency carrier.
In another aspect, a multi-hop relay cellular system, includes a plurality of uplink receivers that includes at least a first uplink receiver, a second uplink receiver, and a third uplink receiver, a plurality of uplink transmitters that include at least a first uplink transmitter, a second uplink transmitter, and a third uplink transmitter, a plurality of downlink receivers that includes at least a first downlink receiver, a second downlink receiver, and a third downlink receiver, a plurality of downlink transmitters that include at least a first downlink transmitter, a second downlink transmitter, and a third downlink transmitter. A first frequency link is carried on a first frequency carrier from the first uplink transmitter to the first uplink receiver, a second frequency link is carried on a second frequency carrier from the first downlink transmitter to the first downlink receiver, a fourth frequency link is carried on the first frequency carrier from the second downlink transmitter to the second downlink receiver, a third frequency link is carried on the second frequency carrier from the second uplink transmitter to the second uplink receiver, a fifth frequency link is carried on the first frequency carrier from the third uplink transmitter to the third uplink receiver, a sixth frequency link is carried on the second frequency carrier from the third downlink transmitter to the third downlink receiver, and a first relay base station and a second relay base station, the first relay base station and the second relay base station are configured to interchange a frequency of operation between the first frequency carrier and the second frequency carrier for uplink transmission and downlink transmission.
In an embodiment, the multi-hop relay cellular system as claimed in claim 5, the relay base station performs a reception of the second frequency link and a reception of the third frequency link on the first frequency carrier, and performs a transmission of the first frequency link on the second frequency carrier and transmission of a fourth frequency on a third frequency carrier.
In another embodiment, the multi-hop relay cellular system as claimed in claim 5, the relay base station performs the transmission of the first frequency link and the transmission of the fourth frequency link on the first frequency carrier, and performs the reception of the second frequency link on the second frequency carrier and the reception of a third frequency on the third frequency carrier.
In yet another embodiment, multi-hop relay cellular system as claimed in claim 5, allocating the first frequency carrier and the second frequency carrier is selected from at least one of (i) no overlap implementation of the first frequency carrier and the second frequency carrier, or (ii) partial overlap implementation of the first frequency carrier and the second frequency carrier, or (iii) complete overlap of the first frequency carrier and said second frequency carrier.
In yet another aspect, a method for relaying in a single-hop or multi-hop relay cellular system by interchanging frequency of operation between backhaul link and access link. The method includes following steps of (a) performing a reception operation in said uplink on the first frequency carrier from the first relay base station to an access base station through a first frequency link, while simultaneously performing, a transmission operation in the downlink on the second frequency carrier from an access base station to the first relay base station through a second frequency link; and (b) performing a reception operation in an uplink on a second frequency carrier from a user equipment (UE) or a second relay base station to a first relay base station through a third frequency link, while simultaneously performing a transmission operation in a downlink on the first frequency carrier from a first relay base station to a user equipment (UE) or a second relay base station through a fourth frequency link.
In one embodiment, the first frequency link 102A is carried on the first frequency carrier 114A from the first uplink transmitter 214 to the first uplink receiver 210. The second frequency link 102B is carried on the second frequency carrier 114B from the first downlink transmitter 224 to the first downlink receiver 226. The third frequency link 102C is carried on the second frequency carrier 114B from the second uplink transmitter 218 to the second uplink receiver 216. The fourth frequency link 102D is carried on the first frequency carrier 114A from the second downlink transmitter 228 to the second downlink receiver 230.
The first and the second frequency carriers 114A and 114B enable frequency division duplexing mode of operation of the cellular system 200. The link between the base station 110 and the relay base station 108 is called as the backhaul link 104 and the link between the relay base station 108 and the UE/relay base station 112 is called as the access link 106. The base station 110 establishes a connection to the user equipment/relay base station 112 through the relay base station 108. The relay base station 108 is configured to switch the frequency of operation between the first frequency carrier 114A (F1) and the second frequency carrier 114B (F2) for downlink/uplink operation based on the configuration. The downlink and the uplink transmissions and reception are performed by the relay base station 108 by flipping the frequencies, such that the transmission and reception operations for each of uplink and downlink are performed on frequency carriers F1 and F2 different from the backhaul configuration.
The relay base station 108 performs reception on the second frequency link 102B and the third frequency link 102C on the second frequency carrier 114B and performs transmission of both the first frequency link 102A and the fourth frequency link 102D on the first frequency carrier 114A. This enables maintaining all transmissions of the relay base station 108 on the first frequency carrier 114A while performing all receptions of the relay base station 108 on the second frequency carrier 114B.
In one embodiment, the relay base station 108 performs a reception on the second frequency link 102B and a reception of the third frequency link 102C on one frequency carrier, and performs a transmission of the first frequency link 102A on the second frequency carrier 114B and transmission of a fourth frequency of a third frequency carrier. In another embodiment, the relay base station 108 performs transmission of the first frequency link 102A and transmission of the fourth frequency link 102D on one frequency carrier, and performs reception of the second frequency link 102B on the second frequency carrier 114A and reception of a third frequency on a third frequency carrier.
Accordingly, the problem of transmit signal affecting the receive signal is avoided in the cellular system 300 as transmission and the reception are performed on different frequency carriers. Each node in the cellular system 300 is enabled to transmit and receive on frequency carriers through static or dynamic control.
The multi-hop relay system 400 also includes a first relay base station 108A and a second relay base station 108B. The first relay base station 108A and the second relay base station 108B are configured to interchange the frequency of operation between the first frequency carrier 114A and the second frequency carrier 114B for uplink transmission and downlink transmission. In one embodiment, relaying in the multi-hop system 400 is configured by toggling the first frequency carrier 114A and the second frequency carrier 114B at each alternate relay in the starting with the first relay base station 108A. For example, a system having ‘n’ number of hops, toggling is performed at relays 1, 3, 5 and so on up till the nth relay.
The four frequency links (102A-D) at the relay base station 108 may be realized using three frequencies. Two transmit or two receive links are operated on one frequency and the remaining links are operated on the remaining two frequencies. In one embodiment, the relay base station performs a reception of the second frequency link 102B and a reception of the third frequency link 102C on one frequency carrier, and performs a transmission of the first frequency link 102A on the second frequency carrier 114B and transmission of a fourth frequency on a third frequency carrier. In another embodiment, the relay base station 108 performs transmission of the first frequency link 102A and transmission of the fourth frequency link 102D on one frequency carrier, and performs reception of the second frequency link 102B on the second frequency carrier 114A and reception of a third frequency on the third frequency carrier.
At step 606, the process involves switching between the first frequency carrier 114A and the second frequency carrier (114B) for each of an uplink and a downlink operation. This enables maintaining different transmission and reception frequencies on uplink and downlink. Accordingly, the problem of transmit signal affecting the receive signal is avoided in the single-hop relay cellular system 300 and the multi-hop relay cellular system 400 as transmissions on either side of the hop is done on a single frequency carrier and receptions are performed using another single frequency carriers. Each node in the single-hop relay cellular system 300 is enabled to transmit and receive on frequency carriers through static or dynamic control.
The single-hop relay cellular system 300 and multi-hop relay cellular system 400 is enclosed. All transmissions of the relay base station 108 are maintained on one frequency carrier while performing all receptions of the relay base station on another frequency carrier. Accordingly, the problem of transmit signal affecting the receive signal is avoided as transmission and the reception are performed on different frequency carriers.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 4848/CHE/2015 | Sep 2015 | IN | national |
