Abstract:
A receiver baseband processor and method for performing preamble detection and Time-of-Arrival, ToA, estimation for a single-tone frequency hopping random access preamble. The processor FFT processes a received signal and identifies logical tones. For each logical tone, the processor reads received symbols; determines a ToA estimate; forms a statistic based on the ToA estimate; compares the statistic to a preamble threshold; and when the statistic is greater than or equal to the threshold, determines a preamble is present and utilizes the ToA estimate for a timing advance command.
Abstract:
The estimation and mitigation of swept-tone interferers includes receiving a composite signal comprising a signal of interest and a swept-tone interferer over an observation bandwidth or a hop bandwidth in a frequency-hopping system. The estimation of the interfering signal may be based on modeling the interferer as a magnitude periodic signal comprising non-overlapping, contiguous epochs, where each epoch may comprise a common pulse shape and a distinct phase rotation. The modeling may be based over the observation bandwidth, the hop bandwidth, or after combining the signal over all the frequency hop bandwidths. The period of the magnitude-periodic signal may be initially determined, and the common pulse shape and each of the distinct phase rotations may then be estimated. These estimates may be used to reconstruct an estimate of the swept-tone interferer, which may be subtracted from the composite signal to generate an interference-mitigated signal of interest.
Abstract:
The estimation and mitigation of swept-tone interferers includes receiving a composite signal comprising a signal of interest and a swept-tone interferer over an observation bandwidth or a hop bandwidth in a frequency-hopping system. The estimation of the interfering signal may be based on modeling the interferer as a magnitude periodic signal comprising non-overlapping, contiguous epochs, where each epoch may comprise a common pulse shape and a distinct phase rotation. The modeling may be based over the observation bandwidth, the hop bandwidth, or after combining the signal over all the frequency hop bandwidths. The period of the magnitude-periodic signal may be initially determined, and the common pulse shape and each of the distinct phase rotations may then be estimated. These estimates may be used to reconstruct an estimate of the swept-tone interferer, which may be subtracted from the composite signal to generate an interference-mitigated signal of interest.
Abstract:
A fast frequency hopping implementation in a phase lock loop (PLL) circuit achieves a PLL lock to a new frequency in a very short period of time. In one instant, frequency allocation at a transceiver is changed. In response, a local oscillator frequency hops to a new center frequency based on the changed frequency allocation. The hopping to the new center frequency is based on two-point modulation of a phase locked loop.
Abstract:
Provided is an apparatus for signal transmission in a Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (FFH-OFDM) communication system which divides all of the available frequency bands into a plurality of sub-carrier bands and includes a plurality of sub-channels each including at least one sub-carrier band. The apparatus includes: a Fast Frequency Hopping (FFH) unit for allocating input data to a number of selected sub-carriers from among the plurality of sub-carriers and for performing fast frequency hopping in accordance with a fast frequency hopping pattern to generate FFH signals, wherein one or more pieces of data comprise the input data and each of the one or more pieces of data is allocated to one of the selected sub-carriers; a Fast Fourier Transform (FFT) unit for performing FFT on FFH signals; a controller for inserting null data into remaining sub-carriers, the remaining sub-carriers comprising sub-carriers other than the selected sub-carriers; a first Inverse Fast Fourier Transform (IFFT) unit for performing IFFT on both the selected sub-carriers comprising the input data and the remaining sub-carriers comprising the inserted null data to generate first IFFT signals; and a transmitter for transmitting the first IFFT signals.
Abstract:
Multiple transmit and receive channels in a communication transceiver may be dynamically configured using corresponding channel registers. In order to support fast frequency hopping, arbitrary sample rate change or profile switching, the present disclosure proposes a profile-based direct memory access (PDMA) that can be used to transfer data from a memory and program specific profile registers in a randomly accessed addressing manner. PDMAs can offload the system processor from reprogramming many system registers based on external or internal events in a multi channels communication system. Furthermore, a PDMA based DMA controller is proposed to configure the fast frequency hopping registers of the transceiver based on PDMA.
Abstract:
A fast frequency hopping implementation in a phase lock loop (PLL) circuit achieves a PLL lock to a new frequency in a very short period of time. In one instant, frequency allocation at a transceiver is changed. In response, a local oscillator frequency hops to a new center frequency based on the changed frequency allocation. The hopping to the new center frequency is based on two-point modulation of a phase locked loop.
Abstract:
Provided is an apparatus for signal transmission in a Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (FFH-OFDM) communication system which divides all of the available frequency bands into a plurality of sub-carrier bands and includes a plurality of sub-channels each including at least one sub-carrier band. The apparatus includes: a Fast Frequency Hopping (FFH) unit for allocating input data to a number of selected sub-carriers from among the plurality of sub-carriers and for performing fast frequency hopping in accordance with a fast frequency hopping pattern to generate FFH signals, wherein one or more pieces of data comprise the input data and each of the one or more pieces of data is allocated to one of the selected sub-carriers; a Fast Fourier Transform (FFT) unit for performing FFT on FFH signals; a controller for inserting null data into remaining sub-carriers, the remaining sub-carriers comprising sub-carriers other than the selected sub-carriers; a first Inverse Fast Fourier Transform (IFFT) unit for performing IFFT on both the selected sub-carriers comprising the input data and the remaining sub-carriers comprising the inserted null data to generate first IFFT signals; and a transmitter for transmitting the first IFFT signals.