In wireless communication systems, there are two types of network topologies based on different paths between a source and a target. In the first type of network topology, the source and the target can communicate with each other directly, an example for the first type of network topology is the cellular network topology, which is as shown in FIG. 1. In the second type of network topology, the source and the target may communicate with each other by data forwarding of a Relay Node (RN). Networks with the second network topology are generally called forwarding networks below. Relay networks, Ad hoc networks, mesh networks, etc. related in the current communication field all belong to the forwarding networks.
Based on the type of the data route, the forwarding network can be categorized as tree-like topology, mesh topology, hybrid topology, etc. The network with the hybrid topology is as shown in FIG. 2. According to the RNs' functions, RNs may be categorized as analog RN and digital RN. Furthermore, the digital RN includes active RN, half-active RN and passive RN.
The analog RN simply receives, amplifies signals, and then transmits the signals.
The active RN receives signals, processes the signals totally according to the control of the active RN, and then transmits the signals processed.
The half-active RN receives signals, processes the signals according to the control of the half-active RN and a controlling node of the half-active RN at the same time, and then transmits the signals processed.
The passive RN receives signals, processes the signals totally according to the control of a controlling node of the passive RN, and then transmits the signals processed.
As for the data transmission in forwarding networks, a typical manner is the hop-by-hop relay manner. That is, the data from super ordinate node is received via air interface and processed (the processing method may be different based on the different category of the node) by the current node, then the data is transmitted from one or more antennas of the current node and received by the subordinate node. As shown in FIG. 3, a forward network includes a Source Node (SN), three RNs (RN1, RN2, and RN3), and a plurality of Target Nodes (TNs). When the SN transmits data to the TN2, the data is transmitted through four hops (SN<->RN1, RN1<->RN2, RN2<->RN3, RN3<->TN2).
In forwarding networks with hop-by-hop relay manner, each RN occupies different radio resources (including time, frequency, codeword, space, and so on) for transmitting and receiving data. With this simple hop-by-hop relay manner, the system performance is improved, such as enlarging the coverage area, improving the user traffic, or increasing the system capacity, at the cost of occupying much more radio resources. Because each RN should occupy different radio resources for receiving and transmitting data, and neighboring nodes (or nodes within interference range) should use different radio resources to avoid degrading system performance incurred by increased system interference.
The prior art provides a forwarding node with a plurality of antennas. However, the inventor found in the inventing process that, the forwarding node in the prior art can not recognize the corresponding relationship between the antennas and the nodes in the coverage area of the antennas. Therefore, upon receiving data, the forwarding node in the prior art transmits data to designated areas by all antennas. Although the coverage area can be enlarged, user traffic can be improved, and the system capacity can be added when using this manner, a great amount of radio resources are still occupied. Moreover, a plurality of antennas transmit the same data will increase system interference in the forwarding network.