1356results about "Multiplex code generation" patented technology

Carrier Interferometry (CI) provides wideband transmission protocols with frequency-band selectivity to improve interference rejection, reduce multipath fading, and enable operation across non-continuous frequency bands. Direct-sequence protocols, such as DS-CDMA, are provided with CI to greatly improve performance and reduce transceiver complexity. CI introduces families of orthogonal polyphase codes that can be used for channel coding, spreading, and/or multiple access. Unlike conventional DS-CDMA, CI coding is not necessary for energy spreading because a set of CI carriers has an inherently wide aggregate bandwidth. Instead, CI codes are used for channelization, energy smoothing in the frequency domain, and interference suppression. CI-based ultra-wideband protocols are implemented via frequency-domain processing to reduce synchronization problems, transceiver complexity, and poor multipath performance of conventional ultra-wideband systems. CI allows wideband protocols to be implemented with space-frequency processing and other array-processing techniques to provide either or both diversity combining and sub-space processing. CI also enables spatial processing without antenna arrays. Even the bandwidth efficiency of multicarrier protocols is greatly enhanced with CI. CI-based wavelets avoid time and frequency resolution trade-offs associated with conventional wavelet processing. CI-based Fourier transforms eliminate all multiplications, which greatly simplifies multi-frequency processing. The quantum-wave principles of CI improve all types of baseband and radio processing.

A communication system and receiver is provided that facilitates increased message size in a communication system that supports a large number of transmitters sharing a common frequency band. The communication system facilitates increased message size by incorporating a plurality of transmit bit sets in each burst of data. The additional transmit bit sets are incorporated into a plurality of transmit codes that are generated using at least one additional spreading code that is orthogonal to the base spreading code. The plurality of transmit codes are then combined into one composite message and the composite message is spread again using another scrambling sequence. The final composite spread message is transmitted to the receiver in the appropriate message time slot, resulting in CDM/TDMA burst signal that facilitates increased message size.

A method of transmitting a control signal in a wireless communication system is provided. The method includes acquiring a resource index, the number of cyclic shifts (CSs) and a CS interval, wherein the number of CSs is an integer multiple of the CS interval, determining a CS index based on the number of CSs and the CS interval, generating a cyclically shifted sequence by cyclically shifting a base sequence by a CS amount obtained from the CS index, generating a modulated sequence based on the cyclically shifted sequence and a symbol for a control signal and transmitting the modulated sequence after mapping the modulated sequence to a resource block obtained from the resource index.

The present invention relates to a method for generating and apparatus for employing code families having desirable correlation properties. Regardless of code length, maximum autocorrelation of the codes is 4 for any nonzero offset and maximum cross-correlation of any two codes from a code family is 4 for any offset. The codes can be used in impulse radio systems and non-impulse radio systems including CDMA, TDMA, FDMA, OFDM and various other frequency hopping and direct sequence systems. The codes can be used to specify various impulse radio and non-impulse radio signal characteristics including pulse position in time, amplitude, width, type, phase, phase difference, frequency, spreading code, etc. The codes have the unique property that they can specify as many as two components in which a signal is not present. A method of code compression is provided.

A method of generating random access preambles includes receiving information on a source logical index and generating random access preambles in the order of increasing cyclic shift from root ZC sequences with the consecutive logical indexes from the beginning of the source logical index until a predetermined number of the random access preambles are found, wherein the consecutive logical indexes are mapped to root indexes of the root ZC sequences.

The present invention provides methods and apparatus to protect user privacy while accessing information in public places, using both public and personal devices. This is achieved by employing a mechanism that prevents private information from being displayed on public devices. Instead, this type of information is made available only to a user's personal device(s) that the user carries and/or trusts. An example embodiment of the invention shows relevant parts of the information content, referred to also as information documents or simply documents, to multiple devices based on privacy level and user preferences. Embodiments of the present invention also provide personalized services based on privacy levels defined by users. These users can for example be customers of a retail store. The service provided is sometimes also based on user history of accessing information documents. It permits personalized information to be sent to a customer's personal device.

Systems (400, 500, 600) and methods (300) for generating a chaotic amplitude modulated signal absent of cyclostationary features by preserving a constant variance. The methods involve: generating a PAM signal including pulse amplitude modulation having a periodically changing amplitude; generating a first part of a constant power envelope signal (FPCPES) by dividing the PAM signal by a square root of a magnitude of the PAM signal; generating a second part of the constant power envelope signal (SPCPES) having a magnitude equal to a square root of one minus the magnitude of the PAM signal; and generating first and second spreading sequences (FSS and SSS). The methods also involve combining the FPCPES with the FSS to generate a first product signal (FPS) and combining the SPCPES with the SSS to generate a second product signal (SPS). A constant power envelope signal is generated using the FPS and SPS.

Transmissions on the dedicated channel are encoded using a set of paramaters that are picked from a large selection of potential parameters. If the remote station does not know the particular set of parameters that were used by a base station, then the remote station would have to attempt to decode the transmission using every set of parameters, until the transmission is decoded correctly. This is an inefficient methodology. Hence, transmission format information is typically transmitted on a broadcast channel so that a remote station could receive the transmission format information. However, the broadcast channel has reliability problems. New methods and apparatus are presented to allow a base station to determine an overlapping set of Walsh code sequences that can be used to send the transmission format information on the dedicated channel, rather than a broadcast channel. Using the overlapping set allows the remote station to decode the information.

A wireless local area network (WLAN) communicatively couples together a group of mobile wireless terminals configured to operate in a wireless wide area network (WWAN). A network-management operator processes WWAN-control messages used by the mobile wireless terminals and the WWAN. One or more of the mobile wireless terminals may function as the network-management operator.

A method and apparatus for code multiplexing one or more control signals onto a shared control channel. According to the present invention, a control signal for transmission from a base station to a mobile station terminal is repeated in each slot of a predetermined time interval. The control signal in each slot is spread using a bit-level spreading sequence, where the bit-level spreading sequence varies from slot to slot according to a predefined sequence-hopping pattern. The spread control signals generated for transmission to each mobile station terminal are then combined and spread using a common channelization code.

A method is provided of a base station for wireless telecommunications changing scrambling code to be applied to pilot signals for transmission. The method comprises automatically:

• • identifying a need to change scrambling code,
  • selecting a new scrambling code for use,
  • reprogramming the base station to use the scrambling code, and
  • using the new scrambling code for subsequent pilot signal transmissions.

An apparatus and method for transmitting a processing result on a received data frame in an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system. The method includes selecting an orthogonal codeword corresponding to the processing result among predetermined orthogonal codewords, and transmitting the selected orthogonal codeword through at least one subcarrier group assigned for transmitting the processing result. A length of the orthogonal codeword is determined according to a number of symbol units included in the subcarrier group, and the predetermined orthogonal codewords are orthogonal with each other.

Techniques to improve the acquisition process in a spread spectrum environment. The signals from different CDMA systems are spread with different sets of PN sequences, with the PN sequences in each set being uncorrelated to the PN sequences in the other sets. By using uncorrelated PN sequences, the likelihood of detecting a pilot signal from an undesired system is reduced or minimized, and the mean time to acquisition of the pilot signal from the desired system is improved. The mobile station can attempt to acquire the pilot signal by processing the received signal with a first set of PN sequences corresponding to a first hypothesis of the particular signal being acquired. If acquisition of the pilot signal fails, a second set of PN sequences corresponding to a second hypothesis is selected and used to process the received signal. The PN sequences in the second set are uncorrelated to the PN sequences in the first set. The PN sequences for the first set can be generated based on the characteristic polynomials defined by IS-95-A, and the PN sequences for the second set can be the reverse of the PN sequences for the first set.

A method is provided for generating a coherent chaotic sequence spread spectrum communications system. The method includes phase modulating a carrier with information symbols. The method also includes generating a string of discrete time chaotic samples. The method further includes modulating the carrier in a chaotic manner using the string of discrete time chaotic samples. Each of the discrete time chaotic samples has a shorter sample time interval than the duration of the information symbols. The generating step includes selecting a plurality of polynomial equations. The generating step also includes using residue number system (RNS) arithmetic operations to respectively determine solutions for the polynomial equations. The solutions are iteratively computed and expressed as RNS residue values. The generating step further includes determining a series of digits in the weighted number system based on the RNS residue values. The method further includes synchronizing the chaos generated at the receiver with that generated at the transmitter without periodic transfer of state update information.

The invention relates to a network device, and a report transfer method based on multi-core processor. Wherein, said network device comprises: classifying unit and transfer processor with multi-core unit; the classifying unit receives report at any port of network device, selects core unit from the transfer processor, and sends received report to selected core unit; one core unit of transfer processor transfers report when receives report. The invention can use classifying unit to select core unit to balance the load between core units, to make them parallel transfer reports, to improve the report transfer ability of network device.

A multiple access, spread-spectrum communication system processes a plurality of information signals received by a Radio Carrier Station (RCS) over telecommunication lines for simultaneous transmission over a radio frequency (RF) channel as a code-division-multiplexed (CDM) signal to a group of Subscriber Units (SUs). The RCS receives a call request signal that corresponds to a telecommunication line information signal, and a user identification signal that identifies a user to receive the call. The RCS includes a plurality of Code Division Multiple Access (CDMA) modems, one of which provides a global pilot code signal. The modems provide message code signals synchronized to the global pilot signal. Each modem combines an information signal with a message code signal to provide a CDM processed signal. The RCS includes a system channel controller is coupled to receive a remote call. An RF transmitter is connected to all of the modems to combine the CDM processed signals with the global pilot code signal to generate a CDM signal. The RF transmitter also modulates a carrier signal with the CDM signal and transmits the modulated carrier signal through an RF communication channel to the SUs. Each SU includes a CDMA modem which is also synchronized to the global pilot signal. The CDMA modem despreads the CDM signal and provides a despread information signal to the user. The system includes a closed loop power control system for maintaining a minimum system transmit power level for the RCS and the SUs, and system capacity management for maintaining a maximum number of active SUs for improved system performance.

A method, system and apparatus for spreading physical channels using partly orthogonal multiple code trees. A portion of a first code tree is used to spread the physical channels. This first code tree is a combination of a channelization code sequence and a first scrambling code sequence. A portion of a second code tree is used to spread the physical channels that are remaining and were not spread using the first code tree. This second code tree is a combination of the channelization code sequence and a second scrambling code formed by modifying the first scrambling code. The portion of the second code tree used to spread the channels is orthogonal to the portion of the first code tree used. A plurality of other code trees could be formed using scrambling codes based on the modification of the first scrambling code.