Abstract: Low complex algorithms for estimating a delay spread or a RMS delay spread of a multipath channel using channel estimates are disclosed, leading to low overall power consumption. According to an embodiment of the present invention, a delay spread or a RMS delay spread of the multipath channel is determined based on a metric calculated as a function of channel estimates. In another embodiment, an average signal to noise ratio is taken into consideration in addition to the metric to estimate the delay spread or the RMS delay spread. In a further embodiment, the delay spread or the RMS delay spread of the multipath channel is estimated based on an average signal to noise ratio and on a metric being a function of the slope between subcarrier channel estimates. The present invention further relates to an apparatus for estimating a delay spread or a RMS delay spread of the multipath channel.
Type:
Grant
Filed:
April 26, 2007
Date of Patent:
June 7, 2011
Assignee:
Nanoradio AB
Inventors:
Magnus Nilsbo, Tharaka Lamahewa, Scott Leyonhjelm
Abstract: An electronic timer system includes a counter-based time generator (10) for continuously generating raw base time, and a translator (20) for translating between raw base time and local precise time using configurable parameter values. The timer system can be used for generating local precise time by capturing a raw base time value from the counter-based time generator (10) in response to an external event such as a trigger pulse, and using the translator (20) to calculate local precise time from the raw base time value and the parameter values. The timer system can also be used for generating a precisely timed output signal using the translator (20) for translation from precise time of a desired timing event to raw base time. This novel design enables simple and cost-effective practical implementations, and may also support power effective operation of the timer system.
Abstract: Background scan for 802.11 client devices allows them to keep most of its components in low power mode when certain criteria are not met. A method for changing dynamically those criteria according to the air data traffic conditions is described in the present invention. This increases the time the system remains in sleep mode and consequently improves the standby current consumption to portable 802.11 enabled media.
Abstract: This invention can generally be described as an overall transmit (TX) scheduler state-machine that is broken down into two different state-machines: One first TX-scheduler state-machine (FTSM), executed in software, and one second TX-scheduler state-machine (STSM) executed in hardware, which is operating in four different basic states. The functional partitioning between the two state-machines is such that the most constrained real-time requirements are allocated to the STSM, while all complex decisions and non time-critical controls are allocated to the FTSM. The invention also relates to a terminal comprising the invented transmit scheduler.