摘要:
Subscriber power levels are adjusted to enhance interference cancellation in a DS-CDMA communication system. A base-station of the communication system receives signals from a plurality of subscribers and evaluates each signal. Based on the evaluation, particular subscribers are commanded to control their power levels such that different predetermined targets for the particular subscribers are maintained. The predetermined targets include, but are not limited to, received power, frame erasure rate, bit error rate and signal quality. The resulting power levels received at the base-station are substantially different, which is beneficially employed to enhance interference cancellation in the DS-CDMA communication system.
摘要:
A dual-mode mobile station (125) transmits an AMPS signal (Td AMPS) concurrently during transmission of a DS CDMA signal (Td DS CDMA) for purposes of handoff of the mobile station from the DS CDMA system to AMPS. Scanning receivers (221) at surrounding AMPS base-stations (135-138) measure the quality of the AMPS signal (Td AMPS) and determine the best base-station for handoff. To ensure a strong signal during concurrent transmission, other mobile stations not undergoing handoff are instructed to notch their transmissions during transmission by mobile station (125) of the AMPS signal (Td AMPS).
摘要:
A communication system receives and codes a plurality of information signals according to coding assignments to produce a plurality of coded baseband signals. From these signals, a simulated composite carrier signal is formed which has all the characteristics of an actual composite carrier signal which would have resulted if the plurality of coded baseband signals had been formed. The simulated composite carrier signal is analyzed to determine its peak-to-average ratio. The communication system selects a different coding assignments for coding the plurality of information signals if, based on the determined peak-to-average ratio and a selection criteria, the coding assignment does not produce the desired results. The communication system selects a different coding assignments until at least one or several desired coding techniques have been identified, ranks the coding techniques and makes a final selection of the coding technique to meet the peak-to-average ratio requirements.
摘要:
In a TDMA cellular network, there is provided a mechanism for shared-carrier frequency-hopping. It comprises: allocating on a frame basis within a reuse diameter to one coverage area during certain timeslot(s) at least one from a pool of TDM-frame-hopped carriers and allocating on a frame basis within that carrier reuse diameter to another coverage area during certain other, substantially non-overlapping timeslot(s) that frame-hopped carrier, all in substantially non-interfering time-synchronism with any proximal reuse of that carrier, whereby the advantages of frequency hopping are obtained. Stated differently, it comprises: at one instant in time, allocating within a reuse diameter to one coverage area at least one of a plurality of hopped carriers and at that same instant in time, allocating within that carrier reuse diameter to another coverage area another of that plurality of hopped carriers, all in time-synchronism with any proximal reuse of that carrier. The control and access carriers may also be included in the hopping pool, causing certain timeslots to be hopped on a sequence different from the others. The pool of hopped carriers is further apportioned among co-located sites into hopping groups, thereby reducing intra-system synchronization requirements. To solve the near/far problem, TDM timeslots bordering hopping boundaries are preferentially allocated to less distant mobile users.
摘要:
An RF cellular TDM communication system employing offset frame synchronization between cells, any cell being omni-directional or directional, such that a frame at one cell is offset by an integral number of frames from another cell; the system incorporating multiplexed speech transcoding of traffic channels from multiple cells while supporting stringent delay requirements. Offset frame synchronization for providing rapid mobile assisted handoff.
摘要:
A handover technique in a cellular radio communication system (100) for handing over a radio (102) from a first channel in a first cell to a second channel in a second cell, the technique comprising generating a fill-in message extrapolated from a message of the radio on the first channel and communicating the fill-in message when the radio has ceased communicating on the first channel; and terminating the fill-in message when the radio begins communicating on the second channel, thereby reducing handover disruption. The messages may be digitized audio messages. A timer (110, 118) may be employed to allow the fill-in message to terminate at substantially the same time as the radio begins communicating on the second channel. Alternatively, the fill-in message may be directly terminated (FIG. 2) in response to the radio beginning to communicate on the second channel. If the messages are data messages, no fill-in message is generated and the handover is completed directly (FIG. 2) in response to the radio beginning to communicate on the second channel.
摘要:
An subband coding system encoder is provided for improving the quality of a reconstructed speech signal. Briefly, the improved subband coding system encoder includes means for improving the selection of the waveform/noise fill gain factor. The improved selection method, according to the invention, is based on the quasi-stationary characteristic of speech, that is, that the short-time frequency spectrum of a speech signal varies slowly with time. Moreover, the amount of fill energy is adaptively determined for each subband according to the shape of the frequency spectrum for each speech frame.
摘要:
A Master device (e.g., a SIM card) is configured with information regarding one or more Slave devices (e.g., SIM cards) that are associated with the Master device. The Master device is installed in a user device that receives content files and access and usage rights from a content provider. The Master device identifies one or more Slave devices that are associated with the Master device and transmits content files and the rights data to the Slave devices. A user device in which a Slave device is installed receives the content files and rights data sent by the Master device. The Slave device extracts a key from the rights data and provides the key to a decryption component of the user device, which uses the key to decrypt the content file.
摘要:
A wireless device such as a cellular phone is disclosed. The cellular phone is adapted to store a voice message picked-up by a microphone and store voice data representing the voice message in a memory. The cellular phone is further adapted to initiate a call such as an emergency 911 call in response to a turbo-dial or speed-dial key stroke initiated by the user. The cellular phone transmits the stored voice message, along with position data obtained by an onboard geolocation receiver, when the call is established.
摘要:
A method (300, 400) of and server (200) for providing assistance with control of a subscriber device is described. The method comprises receiving an instruction message (303) via a network that corresponds to spoken instructions from the subscriber device; converting the spoken instructions to control commands (309); providing a control message corresponding to the control commands (313); and sending the control message to the subscriber device (315), thereby assisting with the control of the subscriber device.