Patent classifications
H04L25/0236
Transmission and receiving method in a wireless communication system
A method and a device for transmitting and receiving data in a wireless communication system are disclosed. In an embodiment the method includes receiving transmission data, dividing the received transmission data into K>1 data streams, where K is a positive integer, feeding each data stream into its associated parallel processing path so as to obtain K modulated data packets j=1, . . . , K from the parallel processing paths, wherein in each processing path the method further includes segmenting the data stream, encoding the segmented data stream with a first error detection code and modulating the error detection encoded segmented data stream so as to obtain a modulated data packet j comprising a plurality of modulated symbols. The method further includes multiplexing the K modulated data packets so that at least one modulated symbol of each modulated data packet j are placed in proximity to each other in time and/or frequency.
METHOD FOR TRANSMITTING OR RECEIVING SIGNAL IN WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR
In an aspect of the present invention, provided is a method for receiving an uplink signal by a base station (BS) in a wireless communication system where a reference signal is not used, including: obtaining information bits by demodulating and decoding a signal of a first user equipment (UE) that is modulated through a differential modulation scheme; estimating a channel between the first UE and the BS using the information bits; and performing successive interference cancellation (SIC) using the signal of the first UE restored through the channel estimation results and the information bits. In this case, the BS may estimate the channel between the first UE and the BS by assuming that an Nth modulation symbol among modulation symbols of the information bits modulated through the differential modulation scheme is fixed to a predetermined constellation point.
DATA DETECTION IN MIMO SYSTEMS WITH DEMODULATION AND TRACKING REFERENCE SIGNALS
What is disclosed is a method for wireless communication comprising receiving a wireless communication via a receiver of the mobile communication device, deriving a demodulation reference signal from a first plurality of symbols of the wireless communication; creating a channel estimation matrix using the demodulation reference signal; inverting the channel estimation matrix to obtain a channel pseudo-inverse matrix; deriving a tracking reference signal from a second plurality of symbols of the wireless communication; calculating a phase shift for one or more additional symbols based on the tracking reference signal; determining a corrected channel pseudo-inverse matrix for the one or more additional symbols by adjusting the channel pseudo-inverse matrix according to the calculated phase shift; and controlling the receiver to accomplish data detection using the corrected channel pseudo-inverse matrix on one or more orthogonal frequency division multiplexing subcarriers.
WIRELESS COMMUNICATION SYSTEMS AND METHODS OF OPERATING THE SAME
Provided are methods of operating a wireless communication system. The methods include determining first resource mapping patterns of a first physical channel used to generate virtual pilot signals so as to perform downlink channel estimation, based on state information of user equipment (UE) in every first period. The first physical channel is mapped onto resource elements adjacent to resource elements onto which pilot signals are mapped, in a time-frequency resource area (TFRA) of a downlink signal based on the determined first resource mapping patterns. A downlink signal of which resource mapping is completed is then transmitted to the UE.
Channel parameter recovery
A system may comprise a finite impulse response circuit configured to receive one or more samples of a first signal and generate an equalized signal based on the plurality of samples of the input signal and one or more updatable tap coefficients. The system may include an adaptation circuit configured to update the one or more updatable tap coefficients based on the plurality of samples of the input signal. The system may further comprise a recovery circuit configured to accumulate one or more retuning values based on the plurality of samples of the input signal and, in response to an error condition, generate one or more retuned tap coefficients for the finite impulse response circuit based on the one or more retuning values and replace the one or more updatable parameters with the one or more retuned parameters.
Channel estimation for FBMC modulation
Channel estimation with reduced overhead in a filter bank multi-carrier (FBMC) system is enabled by use of frequency-time blocks each comprising a pilot field with two pilot symbols and data symbols outside the pilot field. In embodiments, nearest neighbors of the pilot field are populated with data symbols which fulfill one or more symmetry relations enabling approximate interference cancellation. In a first embodiment, the pilot field consists of two frequency-consecutive and time-coinciding positions; the pilot field may be time-initial in a transmission or may be located in the interior of the transmission. In a second embodiment, a block comprises two frequency-coinciding and time-consecutive pilot symbols; the pilot field may be frequency-initial in a transmission or may be located in the interior of the transmission.
NON-STAGGERED REFERENCE SIGNALS AND REPEATED PILOTS IN ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXING
Methods, systems, and devices for wireless communication are described. A wireless communications system may support techniques for using non-staggered reference signals to increase the efficiency of the system and reduce the complexity of channel estimation. A base station may schedule a transmission to a user equipment (UE) including pilot tones mapped to a first symbol and a second symbol. In some cases, the pilot tones on the first and second symbols may be non-contiguous, and the base station may scramble the pilot tones on the first and second symbols according to the same scrambling sequence. In other cases, the pilot tones on the first and second symbols may be contiguous, and the pilot tones may be scrambled according to the same or different scrambling sequences. These techniques may result in reduced complexity for interference estimation and channel estimation at a UE.
System and method for blind channel estimation and coherent differential equalization in an orthogonal frequency division multiplexing (OFDM) receiver
In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive and convert a plurality of orthogonal frequency division multiplexing (OFDM) samples into a plurality of frequency carriers; a detector coupled to the FFT engine to determine a channel estimate for a first frequency carrier using a first channel estimate for the first frequency carrier and a plurality of other channel estimates, each of the plurality of other channel estimates for one of a plurality of neighboring frequency carriers within an evaluation window, and determine a log likelihood ratio (LLR) for the first frequency carrier using the channel estimate for the first frequency carrier; and a decoder coupled to the detector to decode a first OFDM symbol comprising the first frequency carrier using the LLR for the first frequency carrier.
Systems and methods for advanced iterative decoding and channel estimation of concatenated coding systems
Systems and methods for decoding block and concatenated codes are provided, including channel state information estimation such as by using optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics, including HD Radio receivers and systems.
Techniques for improving channel estimation and tracking in a wireless communication system
A technique for performing channel tracking and/or channel estimation in a wireless communication device includes receiving a reference signal and one or more non-error propagation physical channel signals. In general, the one or more non-error propagation physical channel signals must be correctly decoded before a data channel can be decoded. Channel tracking and/or channel estimation are/is then performed based on the reference signal and at least one of the one or more non-error propagation physical channel signals.