Abstract:
A modulator with polarization marking comprising two input ports for receiving two optical signals at one wavelength, and exhibiting essentially perpendicular optical polarization states, capable of phase-modulating those signals with data signals and of combining them with polarization, characterized in that it comprises a source of phase overmodulation for overmodulating the phase of one of said two optical signals, said phase overmodulation exhibiting a modulation frequency substantially lower than the modulation frequency of said data signals. A method and a coherent receiver are also disclosed.
Abstract:
A system for transmitting a wireless countermeasure signal to disrupt third party communications is disclosed that include an antenna configured to receive wireless signals and transmit wireless counter measure signals such that the wireless countermeasure signals are responsive to the received wireless signals. A receiver processes the received wireless signals to create processed received signal data while a spectrum control module subtracts known source signal data from the processed received signal data to generate unknown source signal data. The unknown source signal data is based on unknown wireless signals, such as enemy signals. A transmitter is configured to process the unknown source signal data to create countermeasure signals and transmit a wireless countermeasure signal over the first antenna or a second antenna to thereby interfere with the unknown wireless signals.
Abstract:
This disclosure provides systems, methods and apparatus for finite rate of innovation channel estimation. In one aspect an apparatus for equalizing received signals is provided. The apparatus comprises a signal per-processing unit configured to process received pilot signals transmitted through a sparse channel into at least one composite signal. The at least one composite signal further includes a plurality of signal peaks. The apparatus further comprises a Fourier transform unit configured to transform the at least one composite signal into frequency-domain data and a channel estimation unit configured to estimate at least one delay value and at least one peak value from the frequency-domain data.
Abstract:
A modulator with polarization marking comprising two input ports for receiving two optical signals at one wavelength, and exhibiting essentially perpendicular optical polarization states, capable of phase-modulating those signals with data signals and of combining them with polarization, characterized in that it comprises a source of phase overmodulation for overmodulating the phase of one of said two optical signals, said phase overmodulation exhibiting a modulation frequency substantially lower than the modulation frequency of said data signals. A method and a coherent receiver are also disclosed.
Abstract:
An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters.
Abstract:
An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters.
Abstract:
An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmited signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters.
Abstract:
The present invention relates to a fast fourier transform apparatus and method for multiple input output orthogonal frequency division multiplexing (MIMO-OFDM) system which can reduce the complexity of a hardware without the yield of the system to change as the minimum nontrivial multiplication uses the variable-length operation of 64~512 point while it supports the multiple channel input. The Institute of Electrical and Electronics Engineers (IEEE) 802 which can minimize the hardware complexity even when it's completely supporting 64/128/256/512 point variable-length operation through the mixed-radix (MR) algorithm, the twiddle factor (TF) nontrivial multiplication optimization, and a simplified data mapping, it can also support the variable band width of 20MHz, 40MHz, 80MHz, 160MHz while having data path of 8.@11ac. It has an effect that the performing apparatus of 11ac wireless LAN-system can be implemented in line with the optimum efficiency. [Reference numerals] (110) Data mapping module;(120) Butterfly module [R4BM];(130) Butterfly module [R2BM];(140) Butterfly module [R8BM1];(150) Butterfly module [R8BM2];(160) Data rearrangement module