Embodiments discloses a transmitter for transmitting a Bluetooth packet in an enhanced data rate format. The Bluetooth packet includes a GFSK modulated segment, a Guard segment and a DPSK modulated segment. The transmitter comprises a first multiplexer configured to select a phase signal from a Guard phase signal, a received GFSK phase signal and a received DPSK phase signal based on time; a second multiplexer configured to select a amplitude signal from a Guard amplitude signal, a received GFSK amplitude signal and a received DPSK amplitude signal based on time, a phase to frequency converter communicatively coupled to the first multiplexer and configured to convert the selected phase signal into converted frequency signal. The transmitter further comprises a phase lock loop, a digital to analog converter and a power amplifier.

A radio transmitter (4) comprises an encoder (5) that receives one or more variable message bits, and encodes each message bit that has a first value as a predetermined first binary chip sequence and encodes each message bit that has the opposite value as a predetermined second binary chip sequence. The radio transmitter (4) transmits data packets, each comprising (i) a predetermined synchronization portion, comprising one or more instances of the first binary chip sequence, and (ii) a variable data portion, comprising one or more encoded message bits output by the encoder. A radio receiver (9) receives such data packets. It uses the synchronization portion of a received data packet to perform a frequency and/or timing synchronization operation, and then decodes message bits from the data portion of the data packet.

Systems and methods for efficient estimation of a most likely sequence are provided. In one embodiment, an electronic device includes most likely receiver circuitry that receives a convolutional encoded signal, generates a linearized representation of the convolutional encoded Gaussian minimum-shift keying signal, resulting in a pseudo-symbol stream, estimates a most likely sequence for the pseudo-symbol stream, and decodes the pseudo-symbol stream based upon the most likely sequence.

A system for automatically detecting the PHY mode based on the incoming preamble is disclosed. The system includes a multimode demodulator, which includes a preamble detector and a demodulator. The preamble detector is used to determine when the preamble has been received and the PHY mode being used by the sending node. An indication of the PHY mode is supplied to the demodulator, which then decides the incoming bit stream in accordance with the detected PHY mode. In some embodiments, one demodulator, capable of decoding the bit stream in accordance with a plurality of PHY modes is employed. In other embodiments, the system includes a plurality of demodulators, where each is dedicated to one PHY mode.

Embodiments of the present invention provide a reference signal sending method, a reference signal receiving method, and an apparatus. A reference signal sending method includes: obtaining a reference signal sequence, where the reference signal sequence includes multiple bits and exclusive OR of every two bits separated by one bit in the multiple bits is 1; performing Gaussian Minimum Shift Keying GMSK modulation on the reference signal sequence; and sending a modulated reference signal sequence. In the embodiments of the present invention, a reference signal sequence is designed as a sequence in which exclusive OR of every two bits separated by one bit is 1, GMSK modulation is performed on the reference signal sequence, and the same reference signal sequence is used to perform channel estimation during GMSK demodulation. Compared with a case in which a pseudo random sequence is used as a pilot symbol, channel estimation accuracy is improved.

A multimode receiving device configured to receive a standard Bluetooth data packet and a physical layer data packet with enhanced performance, can include: a receiving circuit configured to convert a received radio frequency signal to a baseband modulated signal; a demodulation circuit configured to select a demodulation scheme that conforms to a Bluetooth standard or one of a plurality of despread demodulation schemes, in order to demodulate the baseband modulated signal; and the plurality of despread demodulation schemes being configured to correspond to a plurality of predetermined spread-spectrum modulation schemes.

A C/N ratio detection circuit includes a voltage detector, an averaging section, a time variation range calculator, and a C/N ratio calculator. The voltage detector measures an input voltage of a signal. The averaging section calculates an average of the input voltage over a predetermined time. The time variation range calculator calculates a time variation range of the input voltage over the predetermined time. The C/N ratio calculator calculates a C/N ratio of the signal by using the average and time variation range of the input voltage.

An apparatus and a method are provided for selecting a receiver in a user equipment (UE). The method includes receiving, at the UE, a signal; determining, at the UE, a switch metric based on correlation metrics of a training sequence of the signal; comparing, at the UE, the switch metric with a threshold; and selecting, at the UE, one of a voice services over adaptive multi-user channels on one slot (VAMOS) receiver and a non-VAMOS receiver based on the comparing result.

Digital mobile communications devices and methods for processing, modulation and demodulation, transmission and reception of spread spectrum signals, Orthogonal Frequency Division Multiplexed (OFDM) signals and conversion of spread spectrum signals into OFDM signals. Received spread spectrum signals from 3G cellular systems are converted into OFDM signals and transmitted in a Wi-Fi network. Received OFDM signals, received in a cellular system in a first RF frequency band, are demodulated and in a repeater mode are re-transmitted in a cellular system in a second OFDM radio frequency band. One or more receivers and demodulators for receiving demodulating and processing received signals into location finder information. A video camera in mobile device generates video signal and transmits video signal with location finder information signal.

Mobile Networks using Orthogonal Frequency Division Multiplex (OFDM) and or spread spectrum modulation and demodulation techniques process in mobile devices spread spectrum signals into OFDM signals. A first mobile device receives and demodulates a spread spectrum modulated signal into a baseband spread spectrum signal and processes the baseband spread spectrum signal into a first OFDM signal. The first OFDM signal is transmitted to a second mobile device. In the second mobile device the received first OFDM signal is demodulated and processed into a second OFDM signal. The second OFDM signal is transmitted in the mobile network. Alternatively, the first mobile device receives, instead of a spread spectrum signal a modulated OFDM signal. The mobile device has a motion detector which generates a motion detector signal for control of the mobile device. The mobile device has a heart rate sensor and measures the heart rate.