Issc Technologies Corp.

Integrated System Solution Corporation

Pansop Kim

Jeng-Hong Chen

Hsin-Hsiang Liu

Wei-Chung Peng

Hsin-Hsu Chi

Ying-Tsung Lin

Yung-Chen Ting

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.

Simplified acquisition apparatus and method for a Bluetooth receiver

A speech detection method is presented, which includes the following steps. A first voice captured device samples a first signal and a second voice captured device samples a second signal. The first voice captured device is closer to a speech signal source than the second voice captured device. A first energy corresponding to the first signal within an interval is calculated, a second energy corresponding to the second signal within the interval is calculated, and a first ratio is calculated according to the first energy and the second energy. The first ratio is transformed into a second ratio. A threshold value is set. It is determined whether the speech signal source is detected by comparing the second ratio and the threshold value.

Speech detection method using multiple voice capture devices

The present invention discloses a method and apparatus to provide, effectively and robustly, a phase reference in phase-domain for digital phase-modulated signals. Not only the first-order but also higher order PLLs are delineated for robust and fast tracking of frequency errors and time-varying frequency errors between the transmitter and the receiver. This invention can be applied to any phase-modulated signal such as PSK, DPSK, &#x3c0;/4-DPSK, and CPM. The decoders with this invention can achieve close to the performance of coherent detection. Reference [1] D. Divsalar and M. K. Simon, 'Multiple-symbols differential detection of MPSK,'., vol. 38, pp. 300-308, March 1990. [2] Specification of the Bluetooth System, 2.0+EDR, 4 Nov. 2004.

Method and apparatus for phase reference tracking of digital phase modulated signals in the receiver

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.

Receivers and symbol decoders thereof

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.

Apparatus and method for signal quality measurement on GFSK signals

The present invention discloses an effective apparatus and method to measure the received signal quality for digital communication systems by measuring error vector measurement (EVM) with embedded EVM measurement block in receivers. The distinction of the present invention is that the EVMand the EVMare measured in the receiver for the SIGNAL fields and DATA fields, respectively. EVMis a good indicator for one spatial stream and EVMis a good indicator for current multiple streams. The receiver determines the optimum number of spatial data streams for feedback to the transmitter based on the combinations of EVMand EVMwith or without other algorithms such as analysis on periodically requested sounding packet. The receiver also determines the optimum modulation and coding schemes for feedback based on the EVM measurements.

Apparatus and method of error vector measurement for digital and multiple-input multiple output IMO communication systems

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.

System and method for providing 3-dimensional joint interleaver and circulation transmissions

System performance in wireless communication is improved by increasing diversity in time, space and frequency. In OFDM-based MIMO systems in which the number of antennas M is greater then the number of simultaneously transmitted OFDM symbols N, circulation transmissions according to the present invention improve signal diversity. In symbol-based circulation transmission, N antennas are chosen from the M available antennas to transmit the N OFDM symbols. In subcarrier-based circulation transmission, M output OFDM symbols are composed from the QAM-mappled samples of the N input OFDM symbols. These M output OFDM symbols are then transmitted from the M antennas simultaneously.

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Torrance, CA, United States of America

Pansop Kim