Secure LoRa communication device with frequency hopping The invention relates to a device combining the use of the LoRa communication protocol with frequency range hopping techniques. The device thus constituted allows to benefit from the advantages of both approaches. A large post with low power consumption and low detectability thanks to LoRa and resilience to jamming and interception thanks to frequency evasion.
According to an embodiment, there is provided a wireless communication system that transmits data from a transmission device to a reception device by using a plurality of frequency channels, in which the transmission device includes a transfer control unit that performs transfer control to transfer a part of traffic of one or more frequency channels in which a BER reaches a predetermined value to one or more other frequency channels in which a BER does not reach the predetermined value, and a reduction control unit that performs, for traffic remaining after the transfer control unit transfers a part of traffic of the frequency channels in which a BER reaches the predetermined value, reduction control to reduce at least one of a multi-level number of multi-level modulation or a coding rate.
In order to maintain performance during wireless communication, a transmitting electronic device may concurrently and independently communicate redundant information to a receiving electronic device. In particular, information associated with a data stream may be communicated to the receiving electronic device using one or more channels by two radios using one or more wirelesslocal area network communication protocols. The packets transmitted by the radios may preferentially include the same information. Moreover, the transmitting electronic device may attempt to maintain the redundant communication if a performance metric associated with the one or more channels degrades. For example, the transmitting electronic device may transfer communication to a different channel or may compress the information in the packets in the one or more channels if the throughput drops below a threshold value. Furthermore, the concurrent communication may allow the transmitting electronic device determine link quality without disrupting the communication of the information.
Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.
Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) may communicate on a primary carrier using a first antenna port. The UE may communicate on a secondary carrier using a second antenna port. The UE may determine whether to switch the secondary carrier from the second antenna port to the first antenna port based on a channel condition associated with the second antenna port. The UE may switch the secondary carrier from the second antenna port to the first antenna port based on a decision to switch the secondary carrier from the second antenna port to the first antenna port. Numerous other aspects are provided.
To divide an image into blocks, group the blocks into some subsets, and associate signs the blocks in the subsets with digital information to encode the blocks by using an entropy encoding module.SOLUTION: An encoding method includes initializing a state variable of an encoding module for a first block of an image, and generating a data sub-stream representing at least one of subsets of encoded blocks. When the current block is the first block in the subset, a symbol generation probability of the first block is determined on the basis of the symbol generation probability of encoded and decoded predetermined blocks in at least one another subset. When the current block is the last encoded block in the subset, while the block in the subset is encoded, entire digital information related to a symbol is written in the sub-stream representing the subset, and the initialized sub-step is implemented.SELECTED DRAWING: Figure 2B
An antenna array of frequency-independent phase shifters may be configured to provide band-specific beamforming over a plurality of operating bands by determining, based on a first frequency allocation on a first operating band with first angular directions, at least a second frequency allocation on a second operation band with a second angular directions, so that a first set of predefined requirements comprising at least beamforming requirements on frequency allocations and angular directions are met on all operating bands, determining beamforming weights, and configuring the antenna array to apply the beamforming weights.
An apparatus for transmitting a broadcast signal according to one embodiment of the present invention comprises: a first RF BICM unit for generating at least one first RF core layer BICM signal and at least one first RF enhanced layer BICM signal; a second RF BICM unit for generating at least one second RF core layer BICM signal; a layered division modulation unit for generating at least one layered division multiplexed signal by performing layered division multiplexing corresponding to at least a part of the at least one first RF core layer BICM signal and at least a part of the at least one first RF enhanced layer BICM signal; and a transmission signal generation unit for generating at least one first RF transmission signal corresponding to the at least one layered division multiplexed signal and at least one second RF transmission signal generated on the basis of at least a part of the at least one second RF core layer BICM signal.
Disclosed is a controller device (4) for Digitally Controllable Scatterer, DCS, assisted transmit diversity. The controller device (4) comprises a processor (41), configured to: determine (803) an encoding function (C) for encoding one or more information symbols (X, X i ) to encoded symbols (χ i , χ j,i ); and determine (804) a frequency mapping (F) for mapping the encoded symbols (χ i , χ j,i ) to frequency resources (f i ) being based on an allocated frequency (f dcs ) of a DCS (24). The controller device (4) further comprises a control communication interface (42), configured to: transmit (805) the encoding function (C) to a transmitter device (1); transmit (807) the frequency mapping (F) to the transmitter device (1) and the receiver device (3); and transmit (808) the allocated frequency (f dcs ) of the DCS (24) to a DCS device (2). This provides new space frequency coding via joint design of the DCS configuration phasors, the transmitter encoding function and the receiverprocessing, enabling the receiver device (3) to perform diversity combining of the received signal in order to estimate the information symbol without any CSI knowledge requirements at the DCS device (2) and transmitter device (1) and without transmitting data knowledge at the DCS.
This application discloses a signal sending method, a signal receiving method, and a communication apparatus. The method includes: A first device sends a first signal to a second device on a first frequency domain unit, and sends a second signal on a second frequency domain unit. The first frequency domain unit includes a first frequency, and the second frequency unit includes a second frequency. An absolute value of a difference between the first frequency and the second frequency is related to one or more of the following: a first bandwidth, a second bandwidth, or a third bandwidth. The first bandwidth is a bandwidth occupied by the first frequency domain unit in frequency domain. The second bandwidth is a bandwidth occupied by the second frequency domain unit in frequency domain. The third bandwidth is a bandwidth occupied by a third frequency domain unit in frequency domain. The third frequency domain unit is used by the first device to send a third signal to a third device. The first signal, the second signal, and the third signal are in one operating band. According to the method, interference can be suppressed without increasing complexity of a radio frequency filter.
A communication apparatus includes: storing means for storing information indicating a first base set including a first base sequence to an N-th base sequence; shifting means for generating a first shift sequence to an N-th shift sequence by determining a shift amount based on transmission data, and cyclic shifting an n-th base sequence (n being an integer from 1 to N) by the shift amount; holding means for holding timing information indicating transmission timings of sequences; and transmitting means for transmitting each shift sequence according to the timing information, wherein the first base sequence to the N-th base sequence satisfy a first condition of: a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is not 0 when a shift amount is 0, and a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is 0 when a shift amount is different from 0 used in data transmission.
The present disclosure relates to techniques for beamforming, in particular for WiFi communication schemes such as IEEE 802.11ax and 802.11be. In particular the disclosure relates to a beamformer device (110) configured to: transmit a request to a beamformee device (120), the request comprising a set of sounding tone indices, the set of sounding tone indices indicating tones for which a report (121) of beamforming information is requested from the beamformee device (120), wherein the tones are defined according to a first WiFi scheme, wherein the set of sounding tone indices is based on a first tone plan (400) defined by the first WiFi scheme for a partial channel bandwidth and on a second tone plan (200) defined by a second WiFi scheme for a full channel bandwidth. The disclosure further relates to a corresponding beamformee device.
The application discloses a sub-carrier space arrangement index method of MIMO-OFDM system. The method groups source bits of a transmitting end, and respectively carries out QAM modulation and index modulation. The bits after index modulation are mapped into a sub-carrier space arrangement matrix, multiplied with a constellation diagram after QAM modulation, and then subjected to space-time mapping to obtain data to be transmitted by sub-carriers of each transmitting antenna. Then, time domain signals to be transmitted by each antenna are generated through IDFT conversion. At a receiving end, the signals are demodulated through a corresponding mode to obtain a sub-carrier space arrangement matrix and a QAM symbol, and the source bit data is obtained through mapping of the sub-carrier space arrangement matrix and index bits, serial-parallel conversion. The method starts from utilization of space resources, can improve frequency spectrumutilization rate, realizes a certain degree of receiving diversity, and is superior to prior art in bit error rate and demodulation complexity, so that communication quality and frequency spectrumutilization rate reach a balance.
The technology of this disclosure relates to a signal modulating method, a signal demodulating method, a device, a storage medium, and a program product. In the signal modulating method according to a first aspect of this disclosure, a sending device modulates a bit sequence onto a plurality of subcarriers through binary phase shift keying (BPSK) constellationpoint mapping, dual carrier modulation (DCM), and a duplication (DUP) operation, where the plurality of subcarriers include a first group of subcarriers and a second group of subcarriers. Then, the sending device changes a phase of first data carried in the first group of subcarriers by 90 degrees or minus 90 degrees, and further generates a modulation signal based on the first data that is carried in the first group of subcarriers and whose phase has been changed and second data carried in the second group of subcarriers.
A wireless communication method and protocol for wirelessRF transmission of data, e.g. audio data, with low latency. The method involves a fixed part (FP) serving as synchronization master, and one or more portable parts (PP) being synchronization slaves. The FP performs scanning between a set of supported channels within one limited frequency band, such as within an ISM band. Further, the FP performs collecting measures of RF interference level on at least a plurality of the supported channels in response to the scanning, preferably using own interference level measurement and by collecting RSSI data from the PP for the supported channels. In response to these measures of RF interference level, the FP executes a selection algorithm for selecting and re-selecting first and second different frequencies for respective first and second duplex RF bearers from the set of supported channels to select the channels with least RF interference. Finally, the FP transmits, in one frame of such as 1 ms to 3 ms length, the same data packet on both of said first and second duplex RF bearer frequencies to the PP. This provides a roboust and low latency wireless interface suitable for Human Interface Devices and audio devices, e.g. for gaming equipment.
A method to transmit data packets includes: in a first transceiver, that includes multiple RF transmitters and an RF receiver, receiving an ACK signal from a second transceiver; determining if a data packet was successfully received, and if so, removing the data packet from the queue. If the queue is empty, the method ends. If not, the method proceeds with the next data packet, determines if the ACK has been received, and if it includes an RF mode with diversity information. If there is no diversity information, the data packet is transmitted conventionally. If there is an RF mode with diversity information, the method transmits the data packet using information from the RF mode. Using the RF mode may include replacing PHY information and activating and setting transmitter frequencies for multiple RF transmitters.
An antenna array of frequency-independent phase shifters may be configured to provide band-specific beamforming over a plurality of operating bands by determining, based on a first frequency allocation on a first operating band with first angular directions, at least a second frequency allocation on a second operating band with a second angular directions, so that a first set of predefined requirements comprising at least beamforming requirements on frequency allocations and angular directions are met on all operating bands, determining beamforming weights, and configuring the antenna array to apply the beamforming weights.
Methods and techniques are described for increasing the reliability of data transmission at a high error performance in wireless transmission. In particular, a group of bits representing the data is split into symbol bits and carrier index bits and one or more component-interleaved symbols are generated. The one or more component-interleaved symbols correspond to complex symbols that are obtained by sequentially forming real and imaginary components of intermediate symbols out of said symbol bits; and interleaving said real and / or imaginary components among the intermediate symbols. A carrier index and a power value is determined for each of the one or more component-interleaved symbols based on the carrier index bits, and each of the one or more component-interleaved symbols is transmitted on a respective carrier given by the determined carrier index and with the determined power value.