The disclosure relates to a transmission device for transmitting a radio signal over a radio channel. The transmission device includes: a radio signal generator, configured to generate a radio signal in time-frequency domain; a channel state information (CSI) interface, configured to receive CSI of the radio channel; a pilot generator, configured to compose a pilot signal from at least one pre-defined pilot signal, wherein a number and a location of the at least one pre-defined pilot signal in the composed pilot signal is determined based on at least one of a latency requirement and/or the received CSI; a pilot insertion unit, configured to insert the composed pilot signal into the radio signal; and a transmission unit configured to transmit the radio signal comprising the inserted composed pilot signal. The disclosure further relates to a reception device for receiving a radio signal over a radio channel.

A method performed by radio network node for enabling channel handling of a channel between a wireless device and the radio network node in a wireless communication network. The channel is defined in continuous time and a sampling rate of the channel is non-uniform. The radio network node predicts a channel gain using a first sampling descriptor indicating a first momentary sampling frequency and a second sampling descriptor indicating a second momentary sampling frequency, wherein the first sampling descriptor operates on a different segment of continuous time than the second sampling descriptor. The predicted channel gain enables channel handling such as channel estimation and link adaptation.

A system and method for estimating clock drift in underwater instruments is provided. The method can include transmitting a signal from a source to a plurality of underwater receivers or a single receiver. Upon recovery of the underwater receivers, an initial sampling frequency value can be used to generate received data waveforms from data stored on each underwater device. The generated received waveforms can be used to generate a channel estimate for each receiver, and the channel estimates can be used to provide an estimate of the source motion during the transmission. The estimated source motion can then be used to estimate the clock drift.

Provided is a data decoding method of a wireless communication device. The method includes receiving a plurality of sub-frames. The method further includes accumulating data signals respectively included in each of the plurality of sub-frames. The method further includes updating a channel estimation value based on reference signals included in a most recent sub-frame of the plurality of sub-frames. The method further includes calculating a log likelihood ratio (LLR) based on the accumulated data signals and the updated channel estimation value. Furthermore, the method includes decoding data based on the LLR.

A method for estimating a signal to interference and noise ratio of a communication link between a fist node and a second node of a wireless communication network, the network comprising a number of further communication links between said first node and a number of further nodes. The method comprises, at the first node, providing first estimates of useful signal powers on all the links; providing second estimates of the signal powers on the link and on the further communication links on the basis of, jointly, the first estimate of the signal power on the link and the first estimates of the signal powers on the further links; estimating the signal to interference and noise ratio as a ratio between the second estimate of the signal power on the link and a power term comprising a sum of the second estimates of the signal powers on the further links.

A communication device is provided that includes a receiver configured to receive a signal. The communication device further includes a determination circuit configured to determine an interference estimation signal of the received signal based on a first signal sample of the received signal and on an interference signal model. The communication device further includes a correction circuit configured to determine a corrected interference estimation signal based on the determined interference estimation signal and on a second signal sample of the received signal. The communication device further includes a subtraction circuit configured to subtract the corrected interference estimation signal from the received signal.

A carrier frequency offset (CFO) tracking circuit includes: a CFO estimation circuit, generating an estimated CFO signal; a loop filter, coupled to the CFO estimation circuit, performing a loop filter operation on the estimated CFO signal according to an initial value to generate a loop filtered result; and an averaging circuit, coupled to the CFO estimation circuit and the loop filter, performing an average operation on the estimated CFO signal to generate the initial value as an average of the estimated CFO signal.

A method of estimating a channel for mobile systems with insufficient cyclic prefix length, wherein the channel comprises a plurality of multipath components (,), includes: receiving a signal (y.sub.n) comprising a plurality of contributions of a transmit signal (x.sub.n[k], x.sub.n-1[k]) transmitted during a plurality of transmission time intervals (n, n1) on a plurality of sub-carriers of known pilots (kP.sub.b) and a plurality of sub-carriers of unknown data (k.Math.P.sub.b); determining an estimate of the plurality of multipath components (,) based on a probabilistic relation between the plurality of first contributions (x.sub.n[k], x.sub.n-1[k]) of the transmit signal, wherein the plurality of first contributions are transmitted during adjacent transmission time intervals (n, n1), and an observation of the received signal (y.sub.n[k]) at a subcarrier (kP.sub.b) of the known pilots, wherein the probabilistic relation is based on statistical properties of the plurality of first contributions (x.sub.n[k], x.sub.n-1[k]) of the transmit signal.

In various embodiments, techniques are provided to determine channel characteristics of various communication systems such as OFDM systems or systems using a plurality of transmit antennas by using various sets of training symbols that produce zero cross-correlation energy. Channel communication can accordingly be simplified as the zero cross-correlation property allows for channel estimation without a matrix inversion.

The present disclosure relates to a 5G or pre-5G communication system to be provided to support a higher data transmission rate beyond the 4G communication system, such as LTE. The present invention provides a method for estimating a downlink channel by a receiver in a wireless communication system, the method comprising: estimating the downlink channel on the basis of a reference signal to recover an information bit, and checking whether the information bit recovery has succeeded; and when the information bit recovery has not succeeded, selecting at least one of the received signals as a virtual reference signal on the basis of the accuracy of the data reconstructed at a related resource location and the correlation between the related resource location and a resource location related to the reference signal, and estimating the downlink channel on the basis of at least one virtual reference signal.