Reception and measurement of MIMO-OFDM signals with a single receiver

A method of processing a received signal having a first plurality of subcarriers from a first transmitter carried over a first channel and a second plurality of subcarriers from a second transmitter carried over a second channel, wherein the first plurality of subcarriers comprises a first plurality of subcarrier pilots and the second plurality of subcarriers comprises a second plurality of subcarrier pilots, the method comprising:

• estimating a first impairment parameter for the first plurality of subcarrier pilots;
• estimating a second impairment parameter for the second plurality of subcarrier pilots;
• removing the first estimated impairment parameter from at least one of the first plurality of subcarrier pilots;
• removing the second estimated impairment parameter from at least one of the second plurality of subcarrier pilots;
• estimating the first channel using the at least one of the first plurality of subcarrier pilots with the impairment parameter removed;
• estimating the second channel using the at least of one of the second plurality of subcarrier pilots with the impairment parameter removed;
• and
• decoding the received signal according to Alamouti space-frequency based coding using the channel estimation of the first channel and the channel estimation of the second channel.

A method of processing a received signal having a first plurality of subcarrier pilots from a first transmitter carried over a first channel and a second plurality of subcarriers pilots from a second transmitter carried over a second channel, the method comprising:

• estimating a first impairment parameter for the first plurality of subcarrier pilots;
• estimating a second impairment parameter for the second plurality of subcarrier pilots;
• removing the first estimated impairment parameter from at least one of the first plurality of subcarrier pilots;
• removing the second estimated impairment parameter from at least one of the second plurality of subcarrier pilots;
• estimating the first channel using the at least one of the first plurality of subcarrier pilots with the impairment parameter removed;
• estimating the second channel using the at least of one of the second plurality of subcarrier pilots with the impairment parameter removed;
• providing a first hypothesis signal which represents a possible variation a signal transmitted by the first transmitter;
• providing a second hypothesis signal which represents a possible variation of a signal transmitted by the second transmitter;
• applying the channel estimation of the first channel to the first hypothesis signal;
• applying the channel estimation of the second channel to the second hypothesis signal;
• and
• combining the first hypothesis signal with the first channel estimation applied and the second hypothesis signal with the second channel estimation applied to create a first combined signal estimate.

A method of processing a received signal comprising a first signal from a first transmitter transmitted over a first channel and a second signal from a second transmitter transmitted over a second channel, the method comprising:

• estimating the first channel;
• estimating the second channel;
• providing a first set of hypothesis signals, wherein each hypothesis signal represents a possible variation of the first signal;
• providing a second set of hypothesis signals, wherein each hypothesis signal represents a possible variation of the second signal;
• applying the channel estimation of the first channel to the hypothesis signals in the first set;
• applying the channel estimation of the second channel to the hypothesis signals in the second set;
• and
• combining the first set hypothesis signals with the first channel estimation applied and the second set hypothesis signals with the second channel estimation applied to create a set of combined signal estimates;
• and
• determining the most accurate combined signal by comparing each combined signal estimate with the received signal.