581results about How to "Improve demodulation performance" patented technology

A method for receiving a downlink signal from a base station (BS) in a multicast broadcast single frequency network (MBSFN) subframe is disclosed. The method is performed by a user equipment (UE) and includes receiving information indicating an MBSFN subframe configured as an almost blank subframe (ABS) (ABS MBSFN subframe) among MBSFN subframes of which a data region is allocated a reduced transmission power lower than a transmission power in a data region of a normal subframe, and demodulating the downlink signal received in the data region of the ABS MBSFN subframe based on a cell-specific reference signal (CRS) in a control region of the ABS MBSFN subframe according to the information.

The invention discloses a transmitting method and device for a downlink control channel. The method comprises the steps of: sending a first signalling to user equipment (UE) by a base station, and informing the UE of whether to remove partial resource elements (REs) in a control domain; and when the first signalling indicates to remove the partial REs in the control domain, mapping the downlink control channel to a physical resource by the base station according to the control domain in which the partial REs are removed, and sending to the UE. According to the invention, the demodulating performance of the UE to the downlink control channel can be increased.

The invention discloses a co-channel full-duplex system based on MPPSK modulation. After the system isolates receiving and sending signals at the radio-frequency head normally, cancellation conducted on leakage self-interference signals is finished on a digital baseband; the cancellation method is conducted after conducting shock filter on MPPSK receiving and sending aliasing signals, extracting and multiplying by coherent carrier, band-pass filtering and digitizing, the result of initial channels of all self-interference channels between the output end of a modulator and a receiver ADC is estimated before formal communication, self-interference offset signals are rebuilt by the adoption of the estimated result, further residual errors are filtered out with the combination of methods of coding rate filtering and double matched filtering of a method of shock filtering-multiplying by the coherent carrier-band-pass filtering-coherent demodulation, and MPPSK receiving signals are demodulated reliably. The co-channel full-duplex system based on MPPSK modulation is free of radio-frequency self-interference cancellation, has low requirements for the dynamic range and sampling rate of the ADC, has high isolation degree for the self-interference signals, and is simple in structure, low in complexity, high in spectrum efficiency and good in demodulation performance.

The invention discloses a multiplexing system, method, and receiving device of multi-carrier communication system sharing control channel resources. The method consists of the steps: A. the control signal of different users in the district divided into at least two groups, the frequency resources of the sharing control channel is divided into at least two frequency resources blocks, the frequency resource blocks are sorted according to certain sequence, and the frequency resources of the first position quadrates with the first position frequency resources of at least one neighboring district; B. a frequency resources block is distributed to each control signal group. The invention distributes the frequency resources of the sharing control signal in the same district to the different control signal groups, so according to the actual situation the different users in the district can be managed effectively, the order of priority of the resource distribution can be determined, the users who has need can get the resource of relatively high priority, and flexible communication management can be realized.

A decision directed phase locked loop (DD-PLL) is efficiently implemented in a communication receiver. The phase locked loop includes an enhanced block decoder inside a phase detector which takes in the baseband complex samples and the current channel phase estimate (or the tracked phase) and generates a feedback phase error term. A loop filter filters the phase error terms and a phase accumulator updates the tracked phase estimate on each iteration of the loop.

The invention proposes an incoherent frequency compensation and demodulation method and a demodulation device which have low power consumption, high performance and use the pseudo-randomness of the received signal phase and the PN code to realize the wireless digital communication data demodulation which has short distance, low power consumption and low packet loss rate through the carrier frequency error compensation and data recovery; the demodulation device is composed of a digital low-converter, a channel filter, a phase arithmetic unit, a phase differentiator, a frequency compensator and a PN code de-spreading correlator; the intermediate signal is converted into the plural baseband signals which are processed with channel outer band noise filtration so that the amplitude-time signal is converted into the phase-time signal; the phase differentiator is adopted to differentiate the phase-time signal; the frequency compensation circuit compensate the carrier frequency according to the phase difference signal and the phase average signal; the carrier frequency and the phase recovery circuit are avoided; the PN code correlator group processes the matching demodulation towards the semi-cosine shaping OQPSK and MSK signals of the DSSS directly to recover the baseband data; the incoherent frequency compensation and demodulation method and the demodulation device has the advantages of simple circuit, less quantity of hardware, easy low power consumption integration, good demodulation performance and being applicable to the wireless satellite navigation and the short-range wireless communication device with batteries as the power supply.

The invention provides a method and a system for processing signals of multiple antennas of a downlink system. The method includes that a base station determines a code word set for cyclic pre-coding according to long channel information of a downlink channel when transmission signals are processed; and the transmission data and demodulation reference signals (DMRS) are subjected to pre-coding according to a cyclic pre-coding mode and the determined code word set for cyclic pre-coding. The method and the system have the advantage that the signal transmission performance can be effectively improved for high-speed user equipment (UE).

The invention discloses sending method and equipment of a multicast control channel. The method comprises the following steps of: independently mapping MCCH (Main Control Channel) onto a corresponding transmission channel; independently mapping the transmission channel onto a corresponding physical channel; and sending the MCCH based on a set repetition period and a set revision period and notifying user equipment a subframe position where the MCCH is located as well as the repetition period and the revision period of the MCCH through broadcast information. The invention also discloses receiving method and equipment of the multicast control channel. By utilizing the invention, UE (User Equipment) can obtain combination gains of the MCCH, and the demodulation performance of the MCCH is enhanced.

Hierarchical modulation preferably uses a 16-ary quadrature amplitude modulation (QAM) modulator with a convolutional encoder that combine to effectively provide unequal protection to two different segments of streaming input data, with improved power efficiency with the same bandwidth efficiency, by encoding the first segment as coded data as LSBs as the second segment remains uncoded as uncoded MSBs, with the MSBs used for QAM constellation modest reliability interquadrant demodulation and detection, and with the LSBs used for low reliability intraquadrant detection, but with the LSBs subject to convolutional encoding and decoding rendering the LSBs with high reliability detection, such that, the two segments have unequal coding and modulation for providing unequal levels of reliability detection.

The invention provides a low-power MSK non-coherent digital demodulating method by adopting the phase axis detection and a demodulator which consists of a phase axis generator, a quantizer, a phase detector, a judgment former, correlator groups, a sign judgment device and a clock selection circuit; wherein, the demodulator does not need an independent carrier frequency and a phase restoration circuit or a data restoration clock circuit; DSSS signals can directly de-spread by adopting the correlator groups without a clock and bit restoration circuit; the algorithm of the slopes of phase changes of base-band signals of PN code sequence is adopted in relative judgments, which can overcome the phase cumulative errors caused by the random clock skew of a sending terminal; in addition, the demodulator has a better compensation ability for frequency errors without special frequency compensation circuits; furthermore, the demodulating performance is unrelated with carrier phases and the synchronization performance of DSSS frequency spread and frames and signs is good. The MSK demodulator is characterized by simple demodulating method, low packet loss rate, few hardware expenses, strong anti-noise ability, low power, easy integration, and the like, and can be applied to modern high-end communication terminals.

The present invention proposes an LTE eNodeB receiver channel estimation technique that is referred to as reduced complexity minimum mean squared error (MMSE) technique for channel estimation. From the invention's assumptions, estimations and modified calculations, the present invention generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates H_LS is as follows: (Formula I) which generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates. As a second aspect of the present invention, it is desired that the SNR be estimated within −3 dB of the actual channel SNR. As a third aspect of the invention, an adaptive method of data channel interpolation from RS channel is being proposed in this invention.

The invention discloses a method and a device for frequency offset compensation. The method includes that when user equipment (UE) is connected in a base station, frequency offset values of input signals of the UE are estimated to obtain Doppler frequency offset values so as to judge whether the Doppler frequency offset values exceed a preset threshold, if yes, the frequency offset compensation is performed on the input signals according to self-adaptive frequency offset correction algorithm, otherwise the frequency offset compensation is performed on the input signals according to unlink double-pilot-frequency frequency offset estimation algorithm. The method and the device for the frequency offset compensation can detect a variation range of frequency in real time, correct baseband signal phase deviation caused by frequency offset, and further improve demodulation performance of a baseband and system throughput.

The invention provides a transmission method for uplink control information and user equipment. The method is used for transmitting uplink control information through a PUSCH (Physical Uplink Shared Channel). The method comprises the following steps: the user equipment acquires the uplink control information; the user equipment acquires a feedback sub-frame corresponding to the uplink control information; the user equipment maps at least one parameter included in the uplink control information onto an uplink control information resource meta-area of the feedback sub-frame respectively according a priority sequence, wherein the uplink control information resource meta-area is determined at least based on a demodulation reference signal (DM-RS) resource meta-area, and the demodulation reference signal (DM-RS) is positioned on a time slot in the feedback subframe; the user equipment transmits the uplink control information on the feedback sub-frame.

The invention discloses a method and a device for processing frequency deviation. The method comprises the following steps that: a terminal performs frequency deviation estimation according to a signal channel value to determine a first frequency deviation estimated value; the terminal performs the frequency deviation estimation according to demodulation data to determine a second frequency deviation estimated value; and the terminal calculates the frequency deviation difference value between the first frequency deviation estimated value and the second frequency deviation estimated value, compares the frequency deviation difference value with a frequency deviation difference threshold valve, and regulates the receiving frequency according to a compared result. According to the method and the device for processing the frequency deviation, the receiving frequency is regulated by combining estimated results of the demodulation data frequency deviation estimation and the signal channel frequency deviation estimation, and the demodulation performance can be effectively improved by giving consideration to the advantages and the disadvantages of both estimation methods when the frequencydeviation is estimated and combining the advantages of demodulation data frequency deviation estimation and the signal channel frequency deviation estimation.

The embodiment of the invention relates to a method for transmitting data, user equipment, and a network side device. The method comprises: first data and a first demodulation reference signal that are sent by a first network side device through n antenna ports as well as second data and a second demodulation reference signal that are sent by a second network side device through m antenna ports are received in a sub frame, wherein time-frequency resources occupied by the first demodulation reference signal are different from the time-frequency resources occupied by the second demodulation reference signal and at least parts of the time-frequency resources occupied by the first data and the second data are overlapped; and the data are demodulated based on the first demodulation reference signal and the second demodulation reference signal. The data transmission method, the user equipment, and the network side device can be applied to multi-point cooperative transmission of simultaneous data sending to user equipment by a plurality of network side devices in a non-quasi-co-address state, thereby guaranteeing orthogonality of demodulation reference signals of the plurality of network side devices.

A method for acquiring scheduling control information in a high speed grouping interface is disclosed in the present invention, comprising steps: to obtain this time scheduling control information through processing the scheduling control information acquired by one time scheduling on the uplink and downlink channels in the system according to the scheduling user service kind, and sending this time scheduling control information by the uplink and downlink channels. A base station is also disclosed in the present invention, comprising a base station acquiring scheduling control information unit, and a user terminal, comprising the terminal acquiring scheduling control information unit. The present invention leads the user applying the HSDPA or HSUPA service to be able to acquire scheduling control information without DPCH companion, reduces effectively physical resource spending brought by companion DPCH, leads the HSDPA/HSUPA speciality to be able to realize.

In a demodulation process of a first modulated signal and a second modulated signal, phase adjustment is automatically performed by generating, in response to demodulation results, an optimum phase value of a second internal reference wave for demodulating the second modulated signal. A phase of a second internal reference wave for demodulating the first modulated signal is also adjusted using the optimum phase value for the automatic adjustment.

The invention discloses a multivariate position random polar MCP-EBPSK (Multivariate Continuous Phase-Extended Binary Phase Shift Keying) modulation and demodulation method, which is based on a corrected random polar continuous phase-extended binary phase shift keying modulation mode. The method involves a multivariate position random polar MCP-EBPSK modulator and a multivariate position random polar MCP-EBPSK signal demodulator. The multivariate position random polar MCP-EBPSK modulator is used for carrying out corrected random polar continuous phase keying to different phase modulation periods of sine wave carriers according to multivariate information symbols; and the multivariate position random polar MCP-EBPSK signal demodulator comprises an impulse filter used for highlighting the phase modulation information of received signals and eliminating the polar change of the received signals so that the demodulation performance is not influenced by the modulation of the multivariate position random polar. In the invention, the transmission rate and the spectrum utilization rate of a random polar CP-EBPSK communication system are multiplied by modulation signals, and the system has narrow occupied bandwidth, wide code rate application range, good demodulation performance and good flexibility for use.

The invention discloses a composite modulation system compatible with medium-wave analogue amplitude modulation (AM) broadcast. According to the system, a low-sideband m-ary position phase keying (MPPSK) signal with modulated high-speed data is adopted to replace a sinusoidal carrier; carrier-retained double sideband amplitude modulation is performed with an analogue audio signal; after a receiver performs up-conversion and impacting filter on the received composite modulation signal and extracts a coherent carrier to multiply, an analogue audio signal is separated by using spectral distribution difference, and MPPSK modulated data is demodulated by using correlation matching. According to the system, the frequency resource and the 9 kHz bandwidth division of the conventional medium-wave amplitude modulation broadcast band, the infrastructures of an amplitude modulation broadcast transmitter, the broadcast system of DSB-AM (Double Sideband Amplitude Modulation) transmission and a mature product of a medium-wave amplitude modulation radio are directly used to realize that the original analogue sound signal and a new digital code stream are really broadcast at the same bandwidth on the same channel at the same time, so that the spectrum utilization efficiency and the energy utilization rate of the digital AM broadcast system are greatly improved.

The present invention provides an interference cancellation apparatus and receiver. The apparatus comprises: an interference cancellation unit configured to, based on preset granularities, seriatim perform interference cancellation on interference on common reference signals (CRSs) of interfering cells in each granularity; wherein in performing interference cancellation on the interference on the CRSs of the interfering cells in each granularity, the interference cancellation is performed based on metric values of the interfering cells and/or a predetermined order of interference cancellation. By using frequency selectivity of inter-cell interference, interference cancellation is performed on interference on CRSs of interfering cells in each granularity based on metric values of the interfering cells and/or a predetermined order of interference cancellation, thereby effectively performing interference cancellation, and increasing the accuracy of UE channel estimation and improving demodulation performance, even if the bandwidths of the cells are different.

An apparatus for time synchronization of an orthogonal frequency division multiplexing (OFDM) system oversamples a received signal using a master clock having a frequency at least four times higher than a minimum sampling frequency in a transmission apparatus, sets one of a plurality of oversampled signals to an on-time signal, and shifts each of the remaining oversampled signals by a predetermined time on the basis of the on-time signal. The apparatus for time synchronization calculates a correlation value by correlating each of the shifted signals and the on-time signal with a previously known signal, detects a maximum energy value among the calculated correlation values, and detects a start point of a frame by comparing the maximum energy value with a predetermined threshold value.