System and method for disintegrated channel estimation in wireless networks
A system and method for disintegrated channel estimation in wireless networks. The system provides a disintegrated channel estimation technique required to accomplish the spatial diversity supported by cooperative relays. The system includes a filter-and-forward (FF) relaying method with superimposed training sequences for separately estimating the backhaul and the access channels. To reduce inter-relay interference, a generalized filtering technique is provided which multiplexes the superimposed training sequences from different relays to the destination by time-division multiplexing (TDM), frequency-division multiplexing (FDM) and code-division multiplexing (CDM) methods.
1. A system for disintegrated channel estimation in a wireless communication network, comprising:
a plurality of wireless relay nodes in communication with a source node and a destination node, each of said plurality of wireless relay nodes including a processor,
wherein the processors cause the plurality of wireless relay nodes to each:
receive a pilot signal and a data signal from the source node;
filter the pilot signal to generate a filtered pilot signal;
process the filtered pilot signal to generate an orthogonal pilot signal;
superimpose the orthogonal pilot signal onto the filtered pilot signal to generate a superimposed filtered pilot signal; and
transmit the superimposed filtered pilot signal to the destination node,
wherein the destination node receives the superimposed filtered pilot signals from the plurality of wireless relay nodes and
estimates disintegrated channel information using the superimposed filtered pilot signals,
wherein the processors further cause each of the plurality of relay nodes to process the data signal into a space-time coded data signal and
transmit the space-time coded data signal to the destination node, and
wherein the destination node receives the space-time coded data signal and processes the space-time coded data signal using the disintegrated channel information.
2. The system of claim 1 , wherein the plurality of relay nodes each operate in a filter-and-forward mode of operation.
3. The system of claim 2 , wherein the plurality of relay nodes communicate with the source node and the destination node using time-division multiplexing (TDM).
4. The system of claim 2 , wherein the plurality of relay nodes communicate with the source node and the destination node using frequency-division multiplexing (FDM).
5. The system of claim 2 , wherein the plurality of relay nodes communicate with the source node and the destination node using code-division multiplexing (CDM).
6. The system of claim 1 , wherein the processors cause the plurality of relay nodes to perform filtering to reduce inter-relay-interference.
7. The system of claim 1 , wherein the processors cause the plurality of relay nodes to apply a training sequence at each relay node, and to multiplex the training sequences.
8. A method for disintegrated channel estimation in a wireless communication network, comprising the steps of:
receiving a pilot signal and a data signal at a plurality of relay nodes in communication with a source node;
filtering the pilot signal at each of the plurality of relay nodes to generate a filtered pilot signal;
process the filtered pilot signal at each of the plurality of relay nodes to generate an orthogonal pilot signal;
superimposing the orthogonal pilot signal onto the filtered pilot signal at each of the plurality of relay nodes to generate a superimposed filtered pilot signal;
transmitting the superimposed filtered pilot signals from the plurality of relay nodes to the destination node,
wherein the destination node receives the superimposed filtered pilot signals from the plurality of wireless relay nodes, and
estimates disintegrated channel information using the superimposed filtered pilot signals;
processing the data signal at each of the plurality of relay nodes into a space-time coded data signal;
transmitting the space-time coded data signals from the plurality of relay nodes to the destination node; and
receiving the space-time coded data signals at the destination node and processing the space-time coded data signals using the disintegrated channel information.
9. The method of claim 8 , further comprising operating the plurality of relay nodes in a filter-and-forward mode of operation.
10. The method of claim 9 , further comprising communicating between the plurality of relay nodes and the source node and the destination node using time-division multiplexing (TDM).
11. The method of claim 9 , further comprising communicating between the plurality of relay nodes communicate and the source node and the destination node using frequency-division multiplexing (FDM).
12. The method of claim 9 , further comprising communicating between the plurality of relay nodes communicate with the source node and the destination node using code-division multiplexing (CDM).
13. The method of claim 9 , further comprising performing filtering at the plurality of relay nodes to reduce inter-relay-interference.
14. The method of claim 8 , further comprising applying a training sequence at each relay node and multiplexing the training sequences.