Abstract:
The present invention discloses an effective apparatus and method to measure the received signal quality for a GFSK modulated signal with (or without) an unknown modulation index. The signal quality measurements are based on the decoded (unknown or known) bits and the trellis of the frequency discriminator output. This trellis is pre-calibrated with a reference Rx. The transmitted modulation index is also accurately estimated in this invention.
Abstract:
This invention describes a programmable, digital implementation to shift an arbitrary frequency, or various frequencies in various communication systems of the original signal in the frequency domain. The correspondent phase accumulation to perform the desired frequency shift per sampling instant is perfectly tracked by counting up or down a simple integer. Several arbitrary frequency shifters with different mathematical models are provided. The correspondent implementations with Look-Up-Tables (LUT) are derived for high-speed implementations without further calculations of the values of the sine and cosine functions every sampling instant. Furthermore, a simple shift-and-add phase rotation is described to replace the four required real multiplications. If the original complex signal contains only one-bit each from real part and imaginary part, a surprisingly simple implementation is derived and disclosed for the overall arbitrary frequency shift operation. Further simplifications are also disclosed to make this invention feasible for high sampling frequencies and small frequency drifts.
Abstract:
A method is provided for mitigating the multipath interference experienced by a present CCK symbol. This method first obtains a set of initial candidates for the present CCK symbol and a set of initial candidates for the next CCK symbol based on the ICI-corrected correlation outputs for the present and next CCK symbols, respectively. The method then obtains, for each of the candidates for the present CCK symbol, first ISI-mitigated correlation outputs where both the ICI due to the present CCK symbol and the ISI due to the next CCK symbol have been corrected. Thereafter, for each of the candidates for the present CCK symbol, and based on the first ISI-mitigated correlation outputs, the method obtains second ISI-mitigated correlation outputs where the ISI due to the previous CCK symbol has also been corrected. The present CCK symbol is then decoded based on the second ISI-mitigated correlation outputs.
Abstract:
System performance in wireless communication is improved by increasing diversity in time, space and frequency. Information to be transmitted is processed by a convolution encoder to produce encoded bits. The encoded bits are interleaved and mapped to subcarriers. Symbols are created from the subcarriers and the symbols are transmitted so as to increase diversity in time, space and frequency. Circulation transmission in addition to interleaving is used to increase diversity. For example, circulation transmission can be symbol based or subcarrier based.
Abstract:
An acquisition scheme is provided for receiving a Bluetooth basic data rate (BDR) or enhanced data rate (EDR) packet. An acquisition apparatus for a Bluetooth receiver includes: a phase differentiator; a plurality of basic building blocks; a plurality of 1-bit switches; and a correlation computation equation. It features an acquisition circuit implementation with 1-bit correlator hardware shared by access code and EDR synchronization sequence correlation computations.
Abstract:
The present invention relates to an adaptive, high cost-performance efficient, and power-saving receiving method used for wireless communication systems, such as but not limited to Bluetooth (BT) system, in particular to a method which can detect the presence or absence of the adjacent channel interference (ACT) before the scheduled starting time for receiving a Bluetooth packet, and accordingly set the receiver configurations including the filter's pass-band bandwidth (BW), filter's order, the sampling rate or the number of analog-to-digital-converter (ADC) output bits, and the automatic-gain-control (AGC) algorithm to determine the low noise amplifier (LNA) and variable gain amplifier (VGA) settings.
Abstract:
The present invention discloses apparatus and method for fast and robust automatic gain control (AGC). By using the power statistics and/or the amplitude statistics of multiple pairs of signed ADC outputs, the additional gain control can be determined and included in a statistics-aided AGC to successfully complete the AGC function for a received signal having a dynamic range up to 100 dB within a few micro-seconds.
Abstract:
A receiver capable of decoding a symbol based on information on a previous symbol, the symbol and a next symbol in a Gaussian frequency shift keying (GFSK) communication system is provided. The receiver includes a discriminator to generate a symbol for each bit in a bit sequence, a first lookup table (LUT) to store a number of bit patterns and mapping patterns, wherein each of the bit patterns is in the form of a set of consecutive bits in the bit sequence and corresponds to a respective one of the mapping patterns, and wherein each of the mapping patterns includes a set of entries and each of the entries results from an operation of attribute values at a sample time in the waveform of a symbol, a calculator to receive a set of consecutive symbols from the discriminator and calculate a distance value between the set of consecutive symbols and each of the mapping patterns, and a comparator to identify one of the mapping patterns with a minimum distance value by comparing among the distance values from the calculator.
Abstract:
A display device includes a display module, an outer housing, a glass cover and a strength-enhanced member. The display module is installed within the outer housing, and the outer housing has a support portion. The glass cover is attached to the support portion. The strength-enhanced member is located within the outer housing, and the strength-enhanced member is disposed closer to a corresponding corner of the outer housing than a corresponding corner of the glass cover is.
Abstract:
The present invention discloses an effective apparatus and method to measure the received signal quality for a GFSK modulated signal with (or without) an unknown modulation index. The signal quality measurements are based on the decoded (unknown or known) bits and the trellis of the frequency discriminator output. This trellis is pre-calibrated with a reference Rx. The transmitted modulation index is also accurately estimated in this invention.