Method and apparatus for transmitting data streams in mimo system

An apparatus for transmitting four data streams in a multiple input multiple output (MIMO) system, wherein four data streams are mapped to four layers in an MIMO channel space for transmission, wherein the four data streams are grouped into two groups, and the two groups are processed by two transport channel processing units separately, and the apparatus comprises:

• an interleaving unit, configured to perform inter-layer interleaving for two data streams in each group to obtain two interleaved data streams;
• a mapping unit, configured to map the two interleaved data streams respectively to two layers in the MIMO channel space;
• and
• a transmitting unit, configured to transmit the two interleaved data streams that are mapped to the two layers;
• when the transmitting unit performs the transmission for the two interleaved data streams, spectrum spreading and scrambling processing are separately performed for the two interleaved data streams, precoding is performed for each code channel or channel by multiplying a coding coefficient, a common pilot channel is added to each precoded code channel or channel, and the two interleaved data streams that have been processed are transmitted on a MIMO channel;
• wherein the different code channels are multiplied by different spreading codes during the spectrum spreading operation.

A method for receiving four data streams in a multiple input multiple output (MIMO) system, wherein four data streams are mapped to four layers in an MIMO channel space for transmission, wherein the four data streams are divided into two groups of data streams, and inter-layer interleaving is performed for the two groups of data streams separately;

• and the method comprises:
• performing front-end receipt of data signals on four antennas in the MIMO system separately, and performing linear minimum mean square error (LMMSE) equation, descrambling, and dispreading for the received data signals separately, to obtain the two groups of data streams, wherein each group of data streams comprises two interleaved data streams that are mapped to two layers;
• performing inter-layer deinterleaving separately for the two data streams comprised in each group of data streams among the two groups of data streams, to obtain four data streams that are not interleaved;
• and
• performing log-likelihood ratio (LLR) and decoding operations separately for the four data streams that are not interleaved, to obtain four bit data streams.

A user equipment, configured to receive four data streams in a multiple input multiple output, MIMO system, wherein the four data streams are mapped to four layers in an MIMO channel space for transmission, the four data streams are divided into two groups of data streams, and inter-layer interleaving is performed for the two groups of data streams separately, and the user equipment comprises:

• a receiver, configured to perform front-end receipt of data signals on four antennas in the MIMO system separately, and perform linear minimum mean square error (LMMSE) equation, descrambling, and dispreading for the received data signals separately, to obtain the two groups of data streams, wherein each group of data streams comprises two interleaved data streams that are mapped to two layers;
• a deinterleaver, configured to perform inter-layer deinterleaving separately for the two data streams comprised in each group of data streams among the two groups of data streams, to obtain four data streams that are not interleaved;
• and
• a decoder, configured to perform log-likelihood ratio (LLR) and decoding operations separately for the four data streams that are not interleaved, to obtain four bit data streams.