Method for transmitting an information sequence
Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive preceding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied.
1. A base station used for a wireless communications system configured to have a plurality of layers, the base station comprising:
a controller configured to, for single codeword transmission, encode a single codeword over all of the plurality of layers and, for multiple codeword transmission, encode each of multiple codewords over one or more of the plurality of layers;
a transmitter configured to transmit data in the plurality of layers to a user equipment; and
a receiver configured to receive a single channel quality index (CQI) from the user equipment as a feedback for the plurality of layers.
2. The base station as in claim 1 , wherein, for the multiple codeword transmission, each of the multiple codewords is encoded over each of the plurality of layers.
3. The base station as in claim 1 , wherein, for the multiple codeword transmission, each of the multiple codewords is encoded over all of the plurality of layers.
4. The base station as in claim 1 , wherein each of the plurality of layers comprises a transmission sequence corresponding to a column of a precoder.
5. The base station as in claim 1 , wherein symbols of each of the multiple codewords are assigned into different layers at different time and frequency in a predetermined order.
6. A user equipment used for a wireless communications system configured to have a plurality of layers, the user equipment comprising:
a receiver configured to receive data in the plurality of layers from a base station; and
a transmitter configured to transmit a single channel quality index (CQI) to the base station as a feedback for the plurality of layers,
wherein, for single codeword transmission, a single codeword is encoded over all of the plurality of layers and, for multiple codeword transmission, each of multiple codewords is encoded over one or more of the plurality of layers.
7. The user equipment as in claim 6 , wherein, for the multiple codeword transmission, each of the multiple codewords is encoded over each of the plurality of layers.
8. The user equipment as in claim 6 , wherein, for the multiple codeword transmission, each of the multiple codewords is encoded over all of the plurality of layers.
9. The user equipment as in claim 6 , wherein each of the plurality of layers comprises a transmission sequence corresponding to a column of a precoder.
10. The user equipment as in claim 6 , wherein symbols of each of the multiple codewords are assigned into different layers at different time and frequency in a predetermined order.
11. A wireless communications system configured to have a plurality of layers, the wireless communications system comprising:
a user equipment; and
a base station configured to, for single codeword transmission, encode a single codeword over all of the plurality of layers and, for multiple codeword transmission, encode each of multiple codewords over one or more of the plurality of layers,
wherein data in the plurality of layers are transmitted from the base station to the user equipment, and
wherein a single channel quality index (CQI) is transmitted from the user equipment to the base station as a feedback for the plurality of layers.
12. The wireless communications system as in claim 11 , wherein, for the multiple codeword transmission, each of the multiple codewords is encoded over each of the plurality of layers.
13. The wireless communications system as in claim 11 , wherein, for the multiple codeword transmission, each of the multiple codewords is encoded over all of the plurality of layers.
14. The wireless communications system as in claim 11 , wherein each of the plurality of layers comprises a transmission sequence corresponding to a column of a precoder.
15. The wireless communications system as in claim 11 , wherein symbols of each of the multiple codewords are assigned into different layers at different time and frequency in a predetermined order.