Method of switching transmission modes in IEEE 802.11n MIMO communication systems
AssigneeSamsung Electronics Co., Ltd.
InventorsHuaning Niu, Chiu Ngo
Life of this patent
Estimating the term…
Abstract
A method and system is provided that selects transmission modes between spatial multiplexing, delay diversity and space-time coding in 802.11n systems. As such, eigen-value computation for mode selection is not required. This provides efficiency, in particular for basic receiver structure where a linear MMSE or ZF MIMO detector is applied. Further, mode selection using a simple metric provides accurate mode selection. In addition by switching between different transmission modes, a link adaptation algorithm according to the present invention provides improved system performance.
Claims35
A method of switching between transmission modes in an IEEE802.11n wireless communication system, comprising steps of:
- determining, by a receiver, a decision metric as a function of post-detection constellation-coding SNR, said determining including:
- estimating communication channel information based on long preamble;
- computing a squared min-distance of constellation for different MCS (modulation coding scheme) with the same transmission rates;
- and
- selecting between transmission modes based on the decision metric.
A controller for switching between transmission modes in an IEEE802.11n wireless communication system, comprising:
- a decision metric calculator configured for determining a decision metric as a function of post-detection constellation-coding SNR by:
- estimating communication channel information based on long preamble;
- computing a squared min-distance of constellation for different MCS (modulation coding scheme) with the same transmission rates;
- and
- a selector that selects between transmission modes based on the decision metric.
A method of switching between transmission modes in an IEEE802.11n wireless communication system, comprising steps of:
- Determining, by a receiver, a decision metric as a function of post-detection constellation-coding SNR including:
- determining a decision metric as a function of a constellation distance and coding rate;
- estimating communication channel information based on long preamble;
- computing a post-detection SNR (PMIMO) for different transmission modes;
- computing a coding loss of higher coding rate (P coding);
- computing a squared min-distance of constellation (d^2 min_constellation) for different MCS (modulation coding scheme) with the same transmission rates;
- and
- computing a decision metric D for each transmission mode, such that each transmission mode has a corresponding decision metric;
- and
- selecting between transmission modes based on the decision metric.
A controller for switching between transmission modes in an IEEE802.11n wireless communication system, comprising:
- a decision metric calculator configured for determining a decision metric as a function of post-detection constellation-coding SNR, a constellation distance and coding rate, the decision metric calculator further configured for:
- estimating communication channel information based on long preamble;
- computing a post-detection SNR (ρMIMO) for different transmission modes;
- computing a coding loss of higher coding rate (ρcoding);
- computing a squared min-distance of constellation (d2min-constellation) for different MCS (modulation coding scheme) with the same transmission rates;
- and
- computing a decision metric D for each transmission mode, such that each transmission mode has a corresponding decision metric;
- and
- a selector that selects between transmission modes based on the decision metric.
Dependencies are inferred from the claim text.