Non-coherent detection method of the number of transmit antenna ports for OFDMA
View Patent ↗A method of non-coherent detection of the number of cell-specific transmit antenna ports for a communications device, includes the steps of, at the communications device: (a) generating a downlink reference signals (RS) sequence replica; (b) for a first possible transmit antenna port only, determining a downlink system bandwidth from non-coherent correlation of the generated downlink RS sequence replica and received RS samples; (c) at the determined downlink system, performing a correlation of the generated downlink RS sequence replica and received RS samples for each of a plurality of possible transmit antenna ports; and (d) determining the number of transmit antennas from a comparison of the correlation results in step (c).
1. A method of non-coherent detection of the number of cell-specific transmit antenna ports for a communications device, the method including the steps of, at the communications device:
(a) generating a downlink reference signals (RS) sequence replica;
(b) for a first possible transmit antenna port only, determining a downlink system bandwidth from non-coherent correlation of the generated downlink RS sequence replica and received RS samples;
(c) at the determined downlink system, performing a correlation of the generated downlink RS sequence replica and received RS samples for each of a plurality of possible transmit antenna ports; and
(d) determining the number of transmit antennas from a comparison of the correlation results in step (c).
2. A method according to claim 1 , wherein the RS sequence replica is generated in step (a) for a maximum system bandwidth.
3. A method according to claim 1 , wherein the downlink system bandwidth is determined in step (b) by performing the non-coherent correlation at a plurality of possible bandwidths, and identifying the bandwidth at which the greatest correlation result is obtained.
4. A method according to claim 1 , wherein step (c) is performed at a plurality of different RS shifts and slot numbers.
5. A method according to claim 1 , wherein the number of transmit antennas is determined in step (d) by identifying the transmit antenna at which the greatest correlation result is obtained.
6. A communications device which performs non-coherent detection of the number of cell-specific transmit antenna ports, the device including:
an RS sequence generator for generating a downlink reference signals (RS) sequence replica;
a bandwidth determination block determining a downlink system bandwidth, for a first possible transmit antenna port only, from non-coherent correlation of the generated downlink RS sequence replica and received RS samples;
a correlation calculator for performing, at the determined downlink system, a correlation of the generated downlink RS sequence replica and received RS samples for each of a plurality of possible transmit antenna ports; and
a correlation results comparator for determining the number of transmit antennas from a comparison of the correlation results carried out by the correlation calculator.
7. A method according to claim 2 , wherein the downlink system bandwidth is determined in step (b) by performing the non-coherent correlation at a plurality of possible bandwidths, and identifying the bandwidth at which the greatest correlation result is obtained.
8. A method according to claim 2 , wherein step (c) is performed at a plurality of different RS shifts and slot numbers.
9. A method according to claim 3 , wherein step (c) is performed at a plurality of different RS shifts and slot numbers.
10. A method according to claim 2 , wherein the number of transmit antennas is determined in step (d) by identifying the transmit antenna at which the greatest correlation result is obtained.
11. A method according to claim 3 , wherein the number of transmit antennas is determined in step (d) by identifying the transmit antenna at which the greatest correlation result is obtained.
12. A method according to claim 4 , wherein the number of transmit antennas is determined in step (d) by identifying the transmit antenna at which the greatest correlation result is obtained.