1829results about "Multiplex code allocation" 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.

With the addition of high-speed data traffic to traditional CDMA cellular networks, there is a need to efficiently utilize system capacity so that the quality of service of existing voice and low-speed data users is maintained while new high-speed data users are added to the network. Methods and systems are presented that control allocation of power to users, quality of service requirements, and / or user activity levels to enhance capacity utilization. These methods and systems are based on a method for estimating the capacity of a CDMA carrier with both voice and data users using an interference-based analysis of the reverse link. In particular, the methods enhance capacity utilization in a multi-code CDMA network architecture, in which several codes are allocated to a single high-speed data user for parallel transmission.

Methods and apparatus are provided for improved long preamble formats in a multiple antenna communication system having N antennas. According to one aspect of the invention, a preamble having a legacy portion and a high throughput portion is transmitted (or received) on each of the N transmit antennas, wherein the legacy portion comprises a legacy long training field and the high throughput portion comprises at least N high throughput long training fields, wherein the N high throughput long training fields are transmitted in N time slots using an N×N orthogonal matrix. The orthogonal matrix can be, for example, one or more of a Walsh matrix and a Fourier matrix. The N time slots can optionally comprise a single symbol.

A novel and useful method and system for resource allocation in OFDM communication systems. The mechanism reduces inter-cell interference by randomizing the inter-cell interference experienced in each cell. The mechanism effectively spreads the resource allocation in each cell in a random manner resulting in statistical-like inter-cell interference behavior. In many cases, use of the mechanism is sufficient to obviate the need for frequency planning between cells. A formula or hardware permutation machine is used to generate a random list of indices. The indices are then used to assign user data to the system resources. One or more parameters defining the random index generator at the transmitter are forwarded to the receiver to enable the local generation of an exact copy of the list of indices generated at the transmitter, thus enabling the DL and UL at the receiver while minimizing the required control channel signaling.

A reference signal sequence assignment method and device are provided by which the influence of inter-cell interference can be reduced and the number of usable cyclic shifted sequences per sector can be increased. In a mobile communications system with a structure including multiple cells each including multiple sectors, a sequence assignment method is employed by which pseudo-orthogonal sequences used for reference signals are assigned to cells or sectors. According to this method, the multiple pseudo-orthogonal sequences are assigned to cells or sectors by using multiple repetition patterns.

An apparatus and method for adaptive broadcast transmission. A broadcast transmission can be received. Insufficiency of a broadcast channel quality can be determined. A negative acknowledgement signal can be sent on a common uplink channel in response to determining the broadcast channel quality is insufficient. The negative acknowledgement signal can be received on the common uplink channel at another location, the negative acknowledgement signal indicating broadcast channel quality is insufficient. The broadcast channel quality can be adjusted in response to receiving the negative acknowledgement signal.

A CDMA modem includes a modem transmitter having: a code generator which provides an associated pilot code signal and which generates a plurality of message code signals: a spreading circuit which produces a spread-spectrum message signal by combining each of the information signals with a respective one of the message code signals; and a global pilot code generator that provides a global pilot code signal to which the message code signals are synchronized. The CDMA modem also includes a modem receiver having an associated pilot code generator and a group of associated pilot code correlators for correlating code-phase delayed versions of the associated pilot signal with a receive CDM signal to produce a despread associated pilot signal. The code phase of the associated pilot signal is changed responsive to an acquisition signal value until a pilot signal is received. The associated pilot code tracking logic adjusts the associated pilot code signal in phase responsive to the acquisition signal so that the signal power level of the despread associated pilot code signal is maximized. Finally, the CDMA modem receiver includes a group of message signal acquisition circuits, each including a plurality of receive message signal correlators which correlate respective local received message code signal to the CDM signal to produce a respective despread received message signal.

An apparatus, system and method can be arranged for coding and / or decoding with a phase invariant coding scheme that is useful for short burst signaling devices. 10-bit data is mapped into a 12-bit data with a non-coherent burst code mapper. A parity generator creates a 12-bit parity data to form a 24-bit extended binary Golay code from the 12-bit data. The values for selected bit fields in the 12-bit data and 12-bit parity data are swapped to generate I and Q data such that sensitivity to changes in rotational phase is removed. I and Q data can be used by a transmitter to transmit a rotationally-invariant signal. On receipt, I and Q signals can be recovered, reverse swapped to generate the parity and data signals, and remapped to recover the transmitted 10-bit data. The receiver can also be arranged to use a soft decoding method for improved signal integrity.

The multicarrier transfer system employing the OFDM / CDMA modulation system comprises a transmitter having an S / P converter which two-dimensionally arranges spread signals for a transmission data array on a frequency and time axes system and then rearrange the spread signals for one transmission data array arranged two-dimensionally. The transmitter transmits the signals generated in the S / P converter. A receiver receives the signals transmitted by the transmitter and demodulates the signal to reconstruct the transmission data array.

A method and apparatus are provided for allocating code resources to ACK / NACK channel indexes, when UEs need ACK / NACK transmission in a wireless communication system in which a predetermined number of orthogonal cover Walsh codes is selected from among available orthogonal cover Walsh codes, at least one subset is formed, having the selected orthogonal cover Walsh codes arranged in an ascending order of cross interference, subsets are selected for use in first and second slots of a subframe, and the orthogonal cover Walsh codes of the subset selected for each slot and ZC sequence cyclic shift values are allocated to the ACK / NACK channel indexes.

A handover method in wireless telecommunication system supporting USTS is disclosed. The method for performing a handover of a mobile station in an asynchronous wireless telecommunication system supporting an uplink synchronous transmission scheme (USTS) mode, includes the steps of: a) performing a mode conversion of the mobile station from the USTS mode to a non-USTS mode based on a first signal measurement result from the mobile station; and b) performing a handover for the mobile station. In another embodiment of the present invention, the method further includes the step of: c) performing a mode conversion from the non-USTS mode to the USTS mode based on a second signal measurement result from the mobile station.