Ordered successive interference cancellation receiver processing for multipath channels

In a multiple-input multiple-output (MIMO) communication system that implements orthogonal frequency division multiplexing (OFDM), a method for processing a plurality of received symbol streams to recover a plurality of transmitted symbol streams, comprising:

• performing spatial or space-time processing on the received symbol streams to provide a plurality of detected symbol streams;
• determining a metric for each of the plurality of detected symbol streams, wherein the metric considers frequency selective response of a plurality of frequency subchannels used to transmit each detected symbol stream;
• selecting the detected symbol stream associated with a best metric for recovery;
• processing the selected detected symbol stream to recover the symbol stream and obtain data transmitted for the symbol stream;
• deriving a plurality of modified symbol streams having estimated interference due to the recovered symbol stream approximately removed;
• and
• processing the modified symbol streams to recover another transmitted symbol stream.

A method for deriving a metric indicative of a received quality of a symbol stream transmitted via a multipath channel, comprising:

• estimating a signal-to-noise-and-interference ratio (SNR) of each of a plurality of frequency bins used to transmit the symbol stream;
• transforming the SNR of each frequency bin to an intermediate value based on a particular function;
• and
• accumulating intermediate values for the plurality of frequency bins to obtain the metric indicative of the received quality of the symbol stream.

A method for deriving a metric indicative of a received quality of a symbol stream transmitted via a multipath channel in a multiple-input multiple-output (MIMO) communication system, comprising:

• estimating a post-detection signal-to-noise-and-interference ratio (SNR) of each of a plurality of frequency bins used to transmit the symbol stream;
• determining a channel capacity of each frequency bin based on the post-detection SNR;
• and
• accumulating channel capacities of the plurality of frequency bins to obtain an overall channel capacity indicative of the received quality of the symbol stream.

A digital signal processing device (DSPD) capable of interpreting digital information to:

• process a plurality of received symbol streams at a receiver of a multiple-input multiple-output (MIMO) communication system to provide a plurality of detected symbol streams, wherein each detected symbol stream is an estimate of a corresponding transmitted symbol stream;
• determine a metric for each detected symbol stream, wherein the metric considers frequency selective response of one or more transmission channels used to transmit the detected symbol stream;
• select the detected symbol stream associated with a best metric for recovery;
• process the selected detected symbol stream to recover the symbol stream and obtain data transmitted for the symbol stream;
• derive a plurality of modified symbol streams having estimated interference due to the recovered symbol stream approximately removed;
• and
• process the modified symbol streams to recover another transmitted symbol stream.

An apparatus in a multiple-input multiple-output (MIMO) communication system, comprising:

• means for processing a plurality of received symbol streams to provide a plurality of detected symbol streams;
• means for determining a metric for each detected symbol stream, wherein the metric considers frequency selective response of one or more transmission channels used to transmit the detected symbol stream;
• means for selecting the detected symbol stream associated with a best metric for recovery;
• and
• means for processing the selected detected symbol stream to recover the symbol stream and obtain data transmitted for the symbol stream.

A receiver unit in a multiple-input multiple-output (MIMO) communication system, comprising:

• a spatial processor operative to process a plurality of received symbol streams based on successive interference cancellation (SIC) processing, wherein for each stage of the SIC processing, the receiver processor is operative to perform spatial or space-time processing on a plurality of input symbol streams for the stage to provide one or more detected symbol streams, wherein the input symbol streams for the first stage are the received symbol streams, and wherein each detected symbol stream is an estimate of a corresponding transmitted symbol stream;
• a data processor operative to, for each stage of the SIC processing, process a selected detected symbol stream to recover the symbol stream and obtain data transmitted for the symbol stream;
• and
• a third processor operative to, for each stage of the SIC processing except for a last stage, determine a metric for each of a plurality of detected symbol streams, select the detected symbol stream associated with a best metric for recovery in the stage, and provide an indication of the selected detected symbol stream for the stage, wherein the metric for each detected symbol stream considers frequency selective response of one or more transmission channels used to transmit the detected symbol stream.