50 results about "Cdma channels" patented technology

A system, method, and receiver for receiving radio signals modulated according to different radio communication standards. Radio signals are received and downconverted to an intermediate frequency (IF) signal. An A / D-converter samples the IF signal at a sampling rate and digitizes the sampled signal into a digital signal. A channelizer filters out at least two modulated channels from the digital signal. A first ago channel is modulated according to a Time Division Multiple Access (TDMA) standard, and a second channel is modulated according to a Code Division Multiple Access (CDMA) standard. A first demodulating unit demodulates the TDMA channel, and a second demodulating unit demodulates the CDMA channel. Each of the demodulating units detects and, when needed, resamples each of the modulated channels individually, and delivers a corresponding demodulated channel. A Frequency Division Multiple Access (FDMA) channel may also be received and processed.

A method and device of sending and receiving encoded media over a CDMA channel. A plurality of speech frames are output by a media codec, and the plurality of encoded media frames are encapsulated into a packet of a first type. The packet of the first type is encapsulated into a datagram of a second type. The datagram of the second type is encapsulated into a datagram of a third type. The datagram of the third type is divided into a plurality of equal-sized pieces, such that each of the equal-sized pieces fits to a specific CDMA channel frame. Each of the CDMA channel frames is sent over a CDMA air interface, and received at a receive end over the CDMA air interface.

The invention relates to the technical field of CDMA wireless video-audio transmission, specifically to a wireless mobile audio-video transmission system. The system comprises a monitoring system of a command and control centre for multiplex transmission, display, storage and remote control of a remote audio-video, and a wireless video-audio transmission system for transmitting video images and sound signals in real time to the command and control centre by binding 4 or more than 4 (8-16) CDMA / EDGE / 3G wireless links. The system further comprises a vehicular wireless video-audio terminal for 4 CDMA channels to transmit audio-video in real time, to record image and sound locally with high definition, and to echo the image and sound locally with high definition. Through practical test, the system uses 4 CDMA links (4 caloric units) to realize a transmission rate of 300-450K / S at most, to smoothly transmit a CIF image (352*288) at a speed of 25 frame / S and to smoothly transmit audio signals.

A mobile station for use in an IS-2000-compatible wireless network. The mobile station is capable of receiving data from a first base station of the wireless network simultaneously in a first code division multiple access (CDMA) channel and a second CDMA channel. The mobile station transmits a capability message to the first base station, the capability message comprising a field indicating that the mobile station is capable of simultaneously operating in a Forward Packet Data channel (F-PDCH) and a Forward Supplemental channel (F-SCH).

The invention provides a training sequence variable step-size least-mean-square algorithm, in particular to a training sequence quick channel estimation method. Employing factors which are capable of adaptively tracking and controlling the changes of characteristic parameters through error estimation, the quick channel estimation method improves the convergence speed of the algorithm and acquires the weight coefficient of an optimum filter speedily. The invention discloses a training sequence least-mean-square characteristic parameter estimation method which is quicker in convergence speed and more precise than prior art. The method is easy to realize and is applicable in communication systems for modulated orthogonal frequency division multiplexing for channel estimation. Meanwhile, the idea of the invention can be applied to CDMA channel estimation devices and TDMA channel estimation devices, and can also be applied to LMS methods and the derivative methods thereof. The channel estimation method relates to the fields of communication, oil and seismic exploration, sonar, image processing, computer vision, biomedical engineering, vibration engineering, radar, remote control and telemetry, as well as aerospace field.

Provided is a method and apparatus for acquiring time information from a CDMA system in a mobile communication terminal. The method includes: searching for a CDMA channel in a predetermined manner when a CDMA modem or module is activated; receiving a sync channel signal via the searched CDMA channel and extracting time information from the sync channel signal; and setting a time of the mobile communication terminal using the extracted time information. Therefore, even when the mobile communication terminal communicates with a system that does not provide time information, the mobile communication terminal can precisely maintain its time by acquiring time information from a CDMA system.

The invention provides an electric energy collecting and running management system on the basis of a station area concentrative service terminal, and a method thereof. The electric energy collecting and running management system is provided with a master system, a station area concentrative service terminal, an electric energy meter collector, a station area electric energy meter and a resident electric energy meter; the master system is in charge for services such as data collecting, processing, managing and analysing, output and the like; the running state of the system is monitored and undated; two communication channels such as GPRS or CDMA and RS232 are used between the master system and the station area concentrative service terminal; the station area concentrative terminal has the functions of distribution transform monitoring, electric usage site management, meter concentrator meter reading and the like; the downlink selects a RF narrowband wireless radio frequency data transmission / power carrier / RS483 interface to be communicated with the electric energy meter collector; meter reading task is sent down to the electric energy meter collector; the terminal collects the electric meter information read by various collectors and analyses all electric meter information; and the uplink transmits all data to the master system by the GPRS / CDMA channels.

In one embodiment, a multi-carrier CDMA network grants radio link resources to a mobile station by maximizing soft handoff conditions, by preserving frequency continuity with the mobile station, or by load balancing across carrier frequencies in two or more cells, or by some combination thereof. The network identifies carrier frequencies having two or more CDMA channels for assignment to the mobile station. If one of those frequencies was used by the mobile station to request resources, it may be advantageous to select that frequency; otherwise or instead, the choice is narrowed to the carrier frequency or frequencies having the greatest number of available radio links. From that point, the choice may be further narrowed, for example, by selecting the carrier frequency having the most favorable CDMA channel loading across two or more cells. In another embodiment, such multi-carrier load balancing is the basis of carrier frequency selection.

An overhead message and a method of performing channel hashing using the same are provided. The overhead message includes first and second fields of an extended CDMA channel list message (ECCLM). The first field contains information indicating whether the ECCLM includes at least one frequency assignment of list of frequency assignments that allows packet data support for a forward packet data channel or a 1×EV-DV system and the second field indicates whether each frequency assignment allows such support, thereby enabling channel hashing to be performed by a packet-data-supportable mobile station of a communication system.

A system and method for determining 1xEV-DO availability for a packet data call in a wireless device is presented. When the wireless device receives a request to initiate a packet data call, the device determines if it currently has access to a preferred 1xEV-DO channel. The determination can be made by consulting a 1xEV-DO availability list stored in persistent memory on the wireless device. If available, the wireless device originates the packet data call on the 1xEV-DO channel. If the device is using a CDMA system that has 1xEV-DO channels but the availability or usability of those channels are unknown, the device polls the signal strength on the 1xEV-DO channels to determine the best 1xEV-DO channel to use for the packet data call. If no 1xEV-DO channel is available or if none of the available 1xEV-DO channels are usable, then the device originates the packet data call on a CDMA channel.

A method and system for providing acknowledgment and / or data rate control (DRC) information with respect to data packets conveyed on a plurality of active forward link (FL) carriers. The number of reverse link (RL) carriers employed for the acknowledgment and / or DRC information may be less than the number of active FL carriers, and may be a single carrier, even when the signaling protocol is, in the limit, consistent with presently-supported standardized CDMA protocols. Code multiplexing techniques are employed inventively to convey information for up to fifteen FL carriers on a single, standard CDMA channel designed to provide such signaling for only a single FL carrier at a time.

The invention discloses a mine laneway uplink time frequency coded cooperation MC-CDMA channel estimation method. The method comprises the steps that firstly, a mine laneway uplink time frequency coded cooperation MC-CDMA data transmission frame with pilot frequency is formed, and the pilot frequency sequences of users are different time delay ectypes of the same pilot frequency sequence. According to the pilot frequency design method, the pilot frequency sequences of the users can be staggered by the length of an MC-CDMA symbol cyclic prefix on the time domain, interference among the users is avoided, and the pilot frequency MC-CDMA symbols of the users can be arranged at the same position in one frame; then, channel estimation is carried out through the received pilot frequency sequences of the users on a base station or a collaborative partnership side, and the estimated value of the gains of a channel corresponding to a subcarrier of each user is obtained. Through the algorithm, the interference among the users can be avoided, and meanwhile the pilot frequency resource utilization ratio can be improved as much as possible.

System and method are provided for redirecting a communication device between a macro network and a femtocell network using a service redirection message (SRDM). In an embodiment, the communication device registers with the network which then determines the subscription status of the communication device to a femtocell network. If the subscription is confirmed, using the SRDM the system redirects the communication device to a communication frequency used by the femtocell network. Upon receipt of the SRDM, the communication devices tunes to a communication frequency specified in the SRDM. The system may segregate the CDMA channels used by the macro network, one set containing channels exclusive to the macro network and the other containing channel or channels used by both the macro network and the femtocell network. In this way, the communication device is prevented from entering a frequency re-hashing loop.

A method and device of sending and receiving encoded media over a CDMA channel. A plurality of speech frames are output by a media codec, and the plurality of encoded media frames are encapsulated into a packet of a first type. The packet of the first type is encapsulated into a datagram of a second type. The datagram of the second type is encapsulated into a datagram of a third type. The datagram of the third type is divided into a plurality of equal-sized pieces, such that each of the equal-sized pieces fits to a specific CDMA channel frame. Each of the CDMA channel frames is sent over a CDMA air interface, and received at a receive end over the CDMA air interface.

Aspects of a method and system for servicing a plurality of users via a plurality of femtocells are provided. In this regard, a cellular enabled communication device may receive portions of a datastream from a plurality of femtocells, reconstruct the datastream from the received portions of the datastream, and process the reconstructed datastream for presentation to a user of the cellular enabled communication device. The received portions may be buffered in the cellular enabled communication device. The portions of the datastream may be associated with a plurality of CDMA channel access codes. The portions of the datastream may be received via a plurality of cellular frequencies. The portions of the datastream may be received during a plurality of TDMA timeslots. Portions of the datastream may be received from a cellular base station. Portions of the datastream may be received from a WiMAX base station.

A method is provided for reduced interference between S / CDMA channels (chips) by selecting a first sequence of spreader functions for a first channel, and selecting a second sequence of spreader functions for a second channel, wherein said second sequence is non-overlapping with and spaced from first said sequence.