摘要:
Enhanced wireless speeds are obtained using multiple transmission beams. In one example, a transmitter has a signal processor to receive a plurality of data streams, a plurality of analog converters each coupled to the signal processor to receive the plurality of data streams from the signal processor and to modulate the data streams onto carrier waves, and a plurality of phase shifters each coupled to an analog converter to each receive a modulated stream. A first antenna is coupled to more than one of the plurality of phase shifters to receive the modulated data stream from each phase shifter and transmit it on its respective carrier wave, and a second antenna is coupled to receive at least one modulated data stream and transmit it on its respective carrier wave.
摘要:
Enhanced wireless speeds are obtained using multiple transmission beams. In one example a transmitter sends data packets through an antenna array using multiple spatial beams and a plurality of analog converters. A receiver receives feedback from a remote station, the feedback including a quality measure of data packets received from the transmitter. A processor to controls transmission parameters of the transmitter using the feedback, the processor having a plurality of states, in a first channel analysis state, the processor determining a beam-forming vector for the antenna array, in a second beam search and training state, the processor determining pre-coding coefficients for the data packets, and in a third high rate transmission state, the processor providing pre-coded data packets to the transmitter for transmission, wherein the processor transitions from the third state to the first state upon receiving a reduced quality measure from the remote station.
摘要:
An initialization method is performed to initialize the states for producing downlink scrambling code for a wideband code division multiple access (WCDMA) mobile device. The initialization method uses an auxiliary linear feedback shift register (x-LFSR) advance the x-initial state to a new initial state that corresponds to a selected downlink scrambling code. The new initial state allows the remaining masks used for generating the downlink scrambling code to be fixed. Memory required to produce the downlink scrambling codes is therefore reduced, as it is no longer dedicated to storing the sets of masks corresponding to each of the possible downlink scrambling codes.
摘要:
A fast, low-complexity detection scheme for determining the delays and gains of different propagation paths (i.e., multi-paths) of a received WCDMA signal. The method utilizes a continuous pilot channel that is scrambled by an known pseudo-random sequence. The received signal is provided to a multi-path searcher that passes the received signal through a matched filter with a specified number of taps. The matched filter correlates the received signal with the pilot channel. The multi-path gain and delay detection is then performed, and the delays and gains are reported for use in the WCDMA system.
摘要:
A mobile device detects downlink transmit diversity. Slot and frame timing knowledge and a downlink scrambling code are applied to pilot and synch channels of the signal. An algorithm suited for the diversity case and an algorithm suited for the non-diversity case are utilized. The output of the diversity algorithm is compared to the output of the non-diversity algorithm. The output yielding the highest energy determines whether downlink transmit diversity is applied. The detection algorithms used in both the diversity and non-diversity cases use phasors to indicate the phase difference between two channels. This phase difference is the basis for determining diversity usage.
摘要:
In one embodiment, the present invention is a method for conserving power supplied to a linear feedback shift register (LFSR) long code (LC) generator, the method including steps of operating the LC generator during pre-assigned time slots; shutting off the LC generator during standby periods between the pre-assigned time slots; and priming starting states of the LC generator for synchronization with pre-assigned time slots following a standby period. This embodiment of the present invention enables power to be removed from the LFSR LC generator as well as the LFSR clock. Because the accuracy of the LFSR clock is usually derived from a system master transistor-controlled crystal oscillator (TCXO), and because the LFSR clock operates at a relatively high rate, the TCXO can also be powered down to conserve power. A low frequency, low power clock source can then be used instead of the higher powered clock source and TCXO to maintain operation of the mobile during the mobile sleep state.