摘要:
Methods for estimating the mass flow rate of NOx in an exhaust stream by correlating the level of NOx to an engine parameter. The level of NOx can be estimated as a function of engine power, of intake pressure, of exhaust temperature, as a function of the percentage of O2 in the exhaust stream, or as a combination of any of these. Once the level of NOx is approximately known, the exhaust system of the engine system can be modified to improve the removal efficiency of NOx and exhaust particulate matter from the exhaust stream. These methods for estimating the NOx mass flow rate can be used for an exhaust configuration that includes a lean NOx catalyst (LNC), a selective catalytic reduction (SCR) catalyst, or a lean NOx trap (LNT). A particulate filter can be present in the exhaust configuration.
摘要:
A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises each of multiple subscribers measuring channel and interference information for subcarriers based on pilot symbols received from a base station, at least one of subscribers selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and the one subscriber receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the one subscriber.
摘要:
A method and apparatus for wireless communication are described. In one embodiment, a method for communicating with a subscriber comprises transmitting orthogonal frequency domain multiplexing (OFDM) signals to the subscriber, and receiving direct-sequence spread spectrum (DSSS) signals from the subscriber.
摘要:
A method and apparatus for wireless communication are described. In one embodiment, a method for communicating with a subscriber comprises transmitting orthogonal frequency domain multiplexing (OFDM) signals to the subscriber, and receiving direct-sequence spread spectrum (DSSS) signals from the subscriber.