A technique for wireless communication of a punctured null data packet with a long training field sequence is disclosed. The long training field (LTF) sequence is generated for the null data packet (NDP) for transmission over a channel having a bandwidth that is an integer multiple of 80 MHz. The LTF sequence is modulated onto a plurality of tones of the channel excluding tones within a punctured subchannel of a plurality of subchannels of the channel. The modulation may be based on a size and location of the punctured subchannel and a symbol duration associated with transmitting the LTF sequence. The NDP is transmitted including the LTF sequence to a second wireless communication device via the channel. A partial bandwidth feedback may be received in response to the LTF in the punctured NDP.

Embodiments of the present disclosure provide a method in a base station for random access preamble detection. The method comprises determining a frequency offset of a received uplink signal and adjusting the received uplink signal with the determined frequency offset. The method also comprises detecting, from the adjusted uplink signal, whether there is a random access preamble with a first false alarm value. Additionally, the method may further comprise detecting from the received uplink signal, whether there is a random access preamble with a second false alarm value, before determining the frequency offset of the received uplink signal. Determining the frequency offset of the received uplink signal may be performed in response that a random access preamble is detected with the second false alarm value, the second false alarm value being higher than the first false alarm value.

A Bluetooth receiver includes a primary circuit path, which can create a first digital IF modulated signal to obtain a Bluetooth load signal at a current Bluetooth frequency point, and an auxiliary circuit path, in parallel with the primary circuit path, which can create a second digital IF modulated signal in a Bluetooth frequency range across multiple Bluetooth frequency points. A signal analysis module of the auxiliary circuit path may evaluate interference levels of the second digital IF modulated signal at the Bluetooth frequency points, by analyzing a Fourier Transformation (FT) spectrum of the second digital IF modulated signal, and to choose a number of working Bluetooth frequency points corresponding to relative low signal strengths in the FT spectrum. This way may efficiently and quickly choose qualified working Bluetooth frequency points for Adaptive Frequency Hopping (AFH) in a single current time slot, without consuming any additional time slots for detection.

Various data transmission detection systems are described. A receiver input through which a wireless data transmission signal is received may be present. A plurality of mixers in communication with the receiver input may be present, which may be digitally implemented. A data transmission detector may be present that receives a mixed wireless data transmission signal from each mixer and creates a plurality of scores. A match detection module may be present that receives the scores and identifies a highest score. The signal mapped to the highest score to be selected for further processing.

The apparatus may be a user equipment (UE). The apparatus receives a transmission of at least one of a plurality of first synchronization signals. The apparatus receives at least one repeat transmission of the at least one of the plurality of first synchronization signals. In an aspect, the transmission and the at least one repeat transmission are received in a same synchronization signal block.

Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication is provided which allows high accuracy estimation of frequency offset, high accuracy estimation of a transmission path fluctuation and high accuracy synchronization/signal detection. Pilot symbol mapping is provided for forming pilot carriers by assigning orthogonal sequences to corresponding subcarriers among OFDM signals which are transmitted at the same time from respective antennas in the time domain. Even when pilot symbols are multiplexed among a plurality of channels (antennas), this allows frequency offset/phase noise to be estimated with high accuracy.

A base station may sense, on a cell using unlicensed spectrum, that the unlicensed spectrum is available for transmission. The base station may transmit, after sensing that the unlicensed spectrum is available, consecutive subframes. Each subframe may include a physical downlink control channel and a physical downlink shared channel.

A wireless device transmits a frame by determining a plurality of Resource Units (RUs) of the frame, providing pilots in a first RU of the frame at a first set of positions, providing pilots in a second RU of the frame at a second set of positions, and transmitting the frame. The first set of positions is different from the second set of positions. A wireless device receives a frame including an RU including pilots and processes the pilots. When an RU for the data symbol includes an odd-numbered lowest subcarrier, the pilots are included at a first set of positions in the resource unit. When the RU includes an even-numbered lowest subcarrier, the pilots are included at a second set of positions in the resource unit. The second set of positions is different from the first set of positions.

A circuit for processing Carrier Aggregation (CA) is provided. The circuit includes a plurality of Component Carrier (CC) processors, each CC processor configured to estimate a frequency offset for a related CC and to compensate the estimated frequency offset, a reference clock generator configured to generate a reference clock using a reference frequency offset as one of frequency offsets output from the plurality of CC processors, a plurality of reception Phase Lock Loop (PLL) units, each reception PLL unit configured to generate a reception carrier frequency for the related CC corresponding to the reference clock, and a plurality of transmission PLL units, each transmission PLL unit configured to generate a transmission carrier frequency for the related CC corresponding to the reference clock.

The Direct Synthesis of a Receiver Clock (DSRC) contributes a method, system and apparatus for reliable and inexpensive synthesis of inherently stable local clock synchronized to a referencing signal received from an external source. Such local clock can be synchronized to a referencing frame or a data signal received from wireless or wired communication link and can be utilized for synchronizing local data transmitter or data receiver. Such DSRC can be particularly useful in OFDM systems such as LTE/WiMAX/WiFI or Powerline/ADSL/VDSL, since it can secure lower power consumption, better noise immunity and much more reliable and faster receiver tuning than those enabled by conventional solutions.