453 results about "Channel assessment" patented technology

A method of controlling operation of a wireless device configured in a zero intermediate frequency architecture including a DC loop and a gain loop. The method includes processing energy in a wireless medium to generate a corresponding receive signal, monitoring the receive signal via a predetermined measurement window, detecting a changed condition in the channel, holding the gain feedback control loop at a constant gain level, and operating the DC loop in an attempt to search a stable DC value for the receive signal while the gain loop is held constant. A first case is DC saturation, where the gain is held constant until DC is controlled. A second case is clear channel assessment, where a prior stored gain setting is applied to the gain loop after detecting the end of the packet. A third case is preparation for receiving an expected acknowledgement packet after transmitting a packet, where again a prior stored gain setting is applied to the gain loop and DC is searched.

Methods (300) and corresponding systems (100) for adapting a clear channel assessment (CCA) threshold in a node in a wireless network includes determining a first successful transmission rate of the node and neighboring nodes in the wireless network when the node is set to use a first CCA threshold. Next, a second successful transmission rate of the node and the neighboring nodes is determined when the node is set to use a second CCA threshold. Thereafter, one of the first and the second CCA thresholds is selected based upon the first and second successful transmission rates. The determining a successful transmission rate of the node and neighboring nodes can include counting successful packet indications transmitted by the node and received by the node from the neighboring nodes. Transmitted successful packet indications can include transmitted acknowledgement messages.

The present invention relates to a method, device and system for dynamically adapting a clear channel assessment threshold of a wireless communications channel by determining the status of a busy channel indicator for at least a first parameter (105) and dynamically changing the clear channel assessment threshold based on the status of the busy channel indicator (110).

A process, system, and apparatus are disclosed for mitigating access point data rate degradation with respect to a wireless communication between a wireless access point and a wireless client device. A channel assessment module is configured to assess the wireless communications, including interference signals, present on available wireless communications channels. The channel assessment module may establish quality parameters that at least partially describe the wireless communications quality of a given channel. A channel selection module is configured to select a best wireless communications channel based on the communications channel assessment. A channel connection module is configured to facilitate wireless communication between the wireless access point and the wireless client device on the best wireless communications channel.

Provided is a method for transmitting, by a transmitter, a first data having periodicity through a channel of an unlicensed band:The transmitter adjusts at least one of transmission timing of the first data and clear channel assessment (CCA) timing for the channel to occupy the channel. The transmitter determines whether the channel may be occupied by performing a CCA on the channel at the CCA timing. The transmitter transmits the first data through the channel at the transmission timing of the first data, when it is determined that the channel may be occupied.

A system and method for classifying channels in a frequency hopping wireless communication system is provided. A data collection engine operates to obtain channel metrics indicating the level of interference for each channel used by the wireless communication system. A data analysis engine operates to provide a channel map for adaptive frequency hopping (AFH) and / or a channel map for channel avoidance. More specifically, the data analysis engine first operates to filter the channel metrics to remove channel metrics indicative of frequency hopping interference. Next, the channels are divided into a number of channel blocks each including at least two adjacent channels. For each channel block, the channel metrics of the channels within the channel block are combined to provide a metric sum. The data analysis engine then operates to classify each channel as usable or unusable based on the metric sums for each of the channel blocks.

Methods and apparatus for processing Physical layer Protocol Data Unit (PPDU) based on Basic Service Set (BSS) identification information in a High Efficiency WLAN (HEW) are described. An embodiment is a method for processing a PPDU by a station (STA) in a wireless local area network. The method may include determining whether the PPDU is transmitted from a different Basic Service Set (BSS) from a BSS to which the STA belongs or a same BSS as the BSS to which the STA belongs; and processing the PPDU using a first type of Clear Channel Assessment (CCA) threshold when the PPDU is determined to be transmitted from the different BSS, wherein the first type of CCA threshold is greater than a second type of CCA threshold which is used when the PPDU is determined to be transmitted from the same BSS.

Dynamic wireless channel selection and protocol control for streaming video utilizing transmission delay / packet loss information and channel utilization statistics. A transmission delay and packet loss monitor generates transmission delay information during the transmission of a video stream to remote wireless device(s) over a first wireless channel by timestamping and monitoring video packet(s) and associated transmission acknowledgement(s). The transmission delay information is compared to a predetermined threshold (e.g., a maximum tolerated delay threshold and / or total packet loss threshold) and, if the threshold is exceeded, a second wireless channel is selected for continued transmission of the video stream. In one mode, channel utilization statistics are likewise examined prior to a channel relocation event. Selection of the second wireless channel may be accomplished through a random or semi-random channel selection process, or through active scanning to collect clear channel assessment statistics for candidate channels. In another mode, at least one transmission protocol parameter is altered in response to a violation of one or more of the predetermined thresholds.

Disclosed are operation method of station in wireless local area network. An operation method comprises setting transmission power of a frame; setting a clear channel assessment (CCA) threshold based on a difference between the set transmission power and a default value of the transmission power; and performing a CCA operation based on the set CCA threshold. Therefore, performance of WLAN can be enhanced.

A communication device of a wireless communication system for handling a random access procedure includes a processing means and a storage unit. The processing means is used for executing a program. The storage unit, coupled to the processing means, is used for storing the program which instructs the processing means to perform the following steps: receiving a configuration message for the random access procedure from a network of the wireless communication system, wherein the configuration message configures the communication device to transmit a first random access preamble; performing a clear channel assessment (CCA) or listen before talk (LBT) operation before transmitting the first random access preamble; and increasing a preamble transmission counter of the first random access preamble by 1 when performing the CCA or LBT operation.

System and method for performing clear channel assessment for simultaneous transmission in a device implementing multiple wireless protocols. The system may include first and second wireless protocol circuitry configured to generate first and second signals, respectively, for wireless transmission according to first and second wireless protocols, respectively. A first in-band signal strength threshold and a second in-band signal strength threshold may be maintained by the first wireless protocol circuitry. It may be determined whether the first or second in-band signal strength threshold should be used in performing the clear channel assessment. Clear channel assessment may be performed using the determined in-band signal strength threshold. Performing clear channel assessment may include comparing an ambient signal strength on a channel with the determined in-band signal strength threshold. The first wireless protocol circuitry may be configured to determine whether to wirelessly transmit first signals based on the clear channel assessment.

The invention provides a data transmission method and device. The method comprises that a base station sends a configuration signaling to user equipment UE, and the configuration signaling carries a clear channel assessment (CCA) parameter of the UE as well as an uplink transmission parameter of the UE; and the base station receives uplink data which is sent by the UE according to the configuration signaling. According to the invention, the problems in carrying out LBT and realizing multiplication of multiple user frequencies when an LTE system carries out operation in a non-authorized carrier frequency range in the related art are solved, and the efficiency of frequency spectrum is improved.

A method to adjust either the detection sensitivity threshold (e.g., the clear channel assessment (CCA) for an 802.11 complaint wireless transceiver) and / or the receiver communication sensitivity threshold (e.g., the start of packet (SOP) for an 802.11 complaint wireless transceiver) to improve performance in a wireless networking environment, such as a high density environment. Both the detection cell and the communication cell can be set equal to each other or the detection cell and communication cell can be independently set. There are also described herein techniques for determining detection cell. Also described herein are techniques for determining communication cell. The present invention includes apparatuses configured to implement a method and / or technique described herein.

Disclosed is a 5G or pre-5G communication system for supporting a data transmission rate higher than that of a 4G communication system such as LTE. Disclosed are: a method for transmitting a signal in an unlicensed band channel on the basis of a counter reduction in the unlicensed band channel of a mobile communication system and a clear channel assessment (CCA) of the channel; and a mobile communication system, and according to an embodiment of the present disclosure, the method for transmitting a signal in an unlicensed band channel on the basis of a counter reduction in the unlicensed band channel of a mobile communication system and a clear channel assessment (CCA) of the channel comprises the steps of: reducing the counter and performing a CCA for the channel, during a first period of transmitting a discovery signal and data; storing the reduced counter when a second period of transmitting only the discovery signal without the data is started; reducing the counter by using the stored counter and performing the CCA for the channel when a third period of transmitting the discovery signal and the data is started; and transmitting the discovery signal or the data on the channel on the basis of the counter value.

Channel state indication signals are transmitted to communication stations via wireless channels and SINR (Signal to Interference and Noise Ratio) values of the channel state indications signals or channel environment parameters according to the SINR values are received from the communication stations as feedback signals. A channel estimation apparatus includes: an average measurement unit for measuring average values of the feedback signals over a period of time, each of the average values being an average value of feedback signals received from an identical communication station during the period of time; and a channel evaluation unit for estimating wireless channel quality of each communication station according to a geographical environment thereof based on the average values measured by the average measurement unit.

A communication system is disclosed in which a communication device communicates with communication apparatus that operates a cell within which the communication device is located. The cell is operated as a licensed assisted access (LAA) cell and has an associated physical uplink control channel (PUCCH). The communication device has a controller that is adapted to: generate a control signal for transmitting to said communication apparatus; perform a clear channel assessment (CCA) on said PUCCH before the control signal is transmitted; and block transmission of the control signal on said PUCCH when said CCA indicates that said channel is not clear. The communication device is further adapted, when said controller has not blocked said transmission of the control signal, to transmit the control signal to said communication apparatus in said PUCCH.

A method for transmitting and receiving a wireless signal in a wireless communication system and an apparatus therefor are disclosed. Specifically, a method for transmitting and receiving a wireless signal in an unlicensed band by a wireless communication device in a wireless communication system comprises the steps of: performing a clear channel assessment (CCA) during a predetermined time interval in the unlicensed band; and transmitting a wireless signal in the unlicensed band when it is determined that the unlicensed band is in an idle state where the unlicensed band is not occupied by other wireless communication devices, wherein when the wireless communication device uses a directional antenna, a first difference between a CCA range and an interference range when the wireless signal is transmitted and received using the directional antenna may be adjusted to be equal to a second difference between the CCA range and the interference range when the wireless signal is transmitted and received using an omni-directional antenna.

The invention discloses a carrier sense method and a system. According to the method, a transmitting terminal sends an idle channel to assess clear channel assessment (CCA) request frames on a main channel of a transmission channel which needs to be detected; the transmitting terminal sends request to send (RTS) frames on the transmission channel which needs to be detected after sending a point coordination function inter-frame space (PIFS) subsequent to transmission of the CCA request frame; and the transmitting terminal performs data transmission on the transmission channel transmitting clear to send (CTS) frames after receiving an indication that CTS frames are permitted to send. The invention also discloses the carrier sense system, which comprises a transmitting terminal and a receiving terminal. According to the method and the system, the power consumption of the receiving terminal is reduced and reliable CCA results of all transmission channels are provided.

A system and method of reducing interference in a wireless communication network is disclosed. The method comprises adapting a transmission power of a signal of a wireless communication device when a clear channel assessment threshold equals a predetermined limit and a packet error rate exceeds a predetermined packet error rate threshold. In particular, the method includes increasing the transmission power of the signal when the clear channel assessment threshold equals a lower limit and the packet error rate exceeds an upper packet error rate threshold and decreasing the transmission power of the signal when the clear channel assessment threshold equals an upper limit and the packet error rate falls below a lower packet error rate threshold.

An apparatus and method for down-link multiple-antenna transmission in a wireless communication system is provided wherein a base station section comprises: a down-link specific physical channel unit, a second common pilot channel unit, a beam weighting unit of common pilot channels, a multiplexing and summing unit, a down-link specific physical channel weighting unit, a specific physical channel and second common pilot channel multiplexing unit, an antenna array unit, a multiple-beam weight vector set unit, up-link specific physical channels, and a feedback bit information unit; and a service cell section or mobile station section comprises: an antenna unit, a channel evaluating unit, a beam selection unit, and a beam quantizing unit. The space characteristics of the physical channels are utilized reasonably. Accordingly, a beam gain is obtained, interference is suppressed effectively, and the apparatus is easy to operate.

There is provided a method, comprising: setting, by a radio device, length for a channel reservation window such that the channel reservation window comprises a plurality of subframes; dividing the channel reservation window at least into a downlink part and an uplink part, wherein the downlink part comprises at least one or more subframes of the plurality of subframes and the uplink part comprises at least one or more other subframes of the plurality of subframes; determine a timing offset between the start of the downlink part and the start of the uplink part, wherein the timing offset is based at least partly on applied timing advance; and defining timings, within the channel reservation window, for at least one of a downlink clear channel assessment—process and an uplink clear channel assessment—process at least partly on the basis of the timing offset.

A method and an apparatus for transmitting a resource, and a method for the HARQ retransmission using an unlicensed band include an operation of performing clear channel assessment (CCA) for the unlicensed band; and an operation of occupying a channel of the unlicensed band according to the CCA and determining whether or not the resource is transmitted based on a position of a transmission time interval (TTI) within a channel occupancy time (COT) for the channel.

A system, method, and signal are disclosed for line probing. The invention provides an improved signal for line probing having desirable characteristics. In various embodiments the signal comprises a periodic sequence having good autocorrelation characteristics. The periodic sequence of the invention provides a faster and more accurate evaluation of the channel. Another embodiment of the invention comprises processing of the received sequence to determine a desired or maximum data rate for the line or channel. The invention also provides an evaluation and calculation of the noise on the line or channel.

Techniques for and apparatus capable of implementing packet detection and signal recognition in wireless communications systems are disclosed. In particular, the disclosed techniques and apparatus incorporate at least one of relative energy detection operable on assessment of a relative energy threshold for an inbound signal borne across an RF channel, carrier sense operable upon on assessment of at least one of a peak-to-sidelobe ratio and peak-to-peak distance defined by the inbound signal, and comparison operable upon demodulated data corresponding to the inbound signal as compared to predetermined preamble data. Clear channel assessment is performed based on determinations undertaken by one or more of the aforementioned relative energy detection, carrier sense and comparison operations.

A method of controlling operation of a wireless device configured in a zero intermediate frequency architecture including a DC loop and a gain loop. The method includes processing energy in a wireless medium to generate a corresponding receive signal, monitoring the receive signal via a predetermined measurement window, detecting a changed condition in the channel, holding the gain feedback control loop at a constant gain level, and operating the DC loop in an attempt to search a stable DC value for the receive signal while the gain loop is held constant. A first case is DC saturation, where the gain is held constant until DC is controlled. A second case is clear channel assessment, where a prior stored gain setting is applied to the gain loop after detecting the end of the packet. A third case is preparation for receiving an expected acknowledgement packet after transmitting a packet, where again a prior stored gain setting is applied to the gain loop and DC is searched.

Uplink control channel management is disclosed for LTE / LTE-A communication systems with unlicensed spectrum in which two or more physical resource blocks (PRBs) are allocated for uplink control channel transmission. The uplink control information (UCI) payload may be determined based on clear channel assessment (CCA) information associated with carriers scheduled for transmission of the UCI data. With the UCI payload determined, two or more uplink control channel messages may be generated according to at least one control channel format, wherein uplink control channel messages include the UCI payload. These generated uplink control channel messages may then be transmitted over the allocated PRBs.

The invention provides a method, transmitting equipment and receiving equipment for controlling sub-channel CCA (Clear Channel Assessment). The method comprises the following steps of: receiving a corresponding RTS (Ready To Send) frame which is transmitted by a transmitting terminal before data are transmitted, carrying out CCA measurement on a sub-channel and transmitting a CTS (Clear To Send) frame to the transmitting terminal on a main channel, wherein the CTS frame is a response to the RTS frame; determining transmission bandwidth after receiving the CTS frame on the transmitting terminal; and receiving the transmitting terminal data transmitted on the transmission bandwidth, and stopping the CCA measurement on the sub-channel after finishing the data transmission. According to the embodiment of the invention, power consumption can be reduced.

Provided are a method and an apparatus for controlling transmission power in a wireless communication system. A wireless device is connected to a first serving cell utilizing a licensed band and a second serving cell utilizing a non-licensed band. The transmission power from the second serving cell is determined by considering the clear channel assessment (CCA) coverage of the wireless device or the second serving cell.