Abstract: The present invention is directed to an interactive marker kit comprised of a case for storing markers. The case has an activity area with the activity area comprised of a marker receptacle for receiving the markers such that when a marker is selected and a base portion of the marker is placed in the marker receptacle, the kit recognizes the marker and provides a response based on the particular marker selected.

Abstract: Practical transmission power adaptation in multicarrier code division multiple access (MC-CDMA) communications is using either a frequency domain technique or a time domain technique or a combined frequency and time domain technique in response to channel variations. With frequency domain power adaptation, the transmission power is allocated over the N? (1?N??N) strongest subcarriers rather than over all possible N subcarriers, where the strongest subcarriers are understood to exhibit the highest channel gains. A substantially optimal N? can be chosen so that the average bit error rate (BER) is minimized. In the time domain power adaptation technique, transmission power is adapted so that the desired signal strength at the receiver output is maintained at a fixed level.

Abstract: Transmit power adaptation for DS/CDMA systems is disclosed for a CDMA system that utilizes a successive interference cancellation receiver on fading channels. The transmission power is adapted in response to channel variations to achieve an arbitrary power profile for received signal powers at the system base station. That is, the received signal powers are distributed with some factor xi's given as: SRi=SR(l)xi, (i=2,3, . . . , K and xl=1) where K is the number of users and SR(i) is the received signal power of the user having the ith strength, and wherein user strengths are ranked in the order of estimated channel gains. The factor xi gives a measure of the disparity between the received power levels. The channel is estimated at both the transmitter and receiver. In one embodiment, the factors, xi, for distributing the signal powers are selected such that the average BER for each user is minimized.