Abstract

A system and method for a radio controlled clock receiver adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using a modulation scheme that adds phase modulation to legacy pulse width modulated/amplitude modulation that allows for greatly improved performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error-correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation scheme is based on a form of phase modulation, such as binary-phase-shift- keying (BPSK) or phase reversal keying (PRK). A superframe comprising multiple frames with repeated information allows for the accumulation of received energy over multiple frames to provide for a corresponding gain in the receiver.

IPC Classes  ?

• H04L 25/40 - Transmitting circuitsReceiving circuits
• H04L 7/04 - Speed or phase control by synchronisation signals
• H04L 27/00 - Modulated-carrier systems

Abstract

A novel and useful system and method for extracting timing, time and additional information from a broadcast received in a radio controlled clock (RCC) receiver. The RCC receiver extracts timing information represented by a known synchronization sequence that is used for acquisition and tracking purposes. The RCC receiver extracts time information as a merged 26-bit time information word linearly coded into 31 bits comprising the number of minutes (or hours) since the turn of the current century. A minute counter representing the 26 bits is converted into the date, hour, and minute. The RCC extracts additional information including the schedule for the next daylight saving time transition and for an imminent leap second. The communications protocol optionally employs error correcting codes to provide protection for data fields in the frame, which the RCC may use to enhance reception reliability in the presence of noise and interference.

IPC Classes  ?

• G04G 9/00 - Visual time or date indication means

Abstract

A configurable system and method for a radio controlled clock (RCC) receiver adapted to apply different strategies for extracting timing and time information from a phase modulated signal depending on the type of application the RCC is used in and on the reception conditions. The official time signal is broadcast from a central location using a modulation scheme which includes phase modulation that alternates between different information rates, allowing for multiple alternative reception modes that are suited for different ranges of signal-to-interference-and-noise-ratio (STNR). The operation of the RCC is configured by the application that hosts it, such that the reception performance and the energy consumption best suit that application. The reception mode used by the RCC at a given time may be selected automatically, i.e. without user intervention, based on the device's profile of operation and the reception conditions.

IPC Classes  ?

• H04L 7/04 - Speed or phase control by synchronisation signals

Abstract

A novel and useful system and method for leap second and daylight saving time (DST) correction for use in a radio controlled clock (RCC) receiver. The RCC receiver extracts schedule information from the frame, including the time for the DST transition and whether a leap second needs to be added at the end of this half-year. Linear error correcting coding is used for the leap second and the DST on/off indications, while non-linear error correcting coding (e.g., a look up table) is used for the DST schedule to enhance reception reliability in the presence of noise and interference. The one second/one hour corrections are scheduled to occur when they should take place and the correction is applied exactly when DST or leap second is to go into effect, without having to receive anything around the time of the correction.

IPC Classes  ?

• G04G 9/00 - Visual time or date indication means
• G04G 5/00 - Setting, i.e. correcting or changing, the time-indication

Abstract

A system and method for a radio controlled clock (RCC) receiver adapted to receive phase modulation over a pulse width modulated/amplitude modulated signal. The RCC adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using a modified modulation scheme, which adds phase modulation over the legacy amplitude modulation, such as the legacy WWVB modulation, thus improving performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error- correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation is based on phase modulation, such as binary-phase-shift-keying (BPSK) or phase reversal keying (PRK). The reception of multiple frames with repeated or sequential information allows for the accumulation of received energy over multiple frames to provide for a corresponding gain in the receiver.

IPC Classes  ?

• G04G 7/02 - by radio

Abstract

An integrated circuit (IC), a method of operating the IC and devices incorporating the IC. In one embodiment, the IC includes: (1) a monolithic substrate and (2) a time code receiver supported by the monolithic substrate and configured to receive a timing signal and employ the timing signal to adjust a local oscillator of a real time clock (RTC).

IPC Classes  ?

• G04R 20/10 - Tuning or receivingCircuits therefor

Abstract

A system-on-a-chip (SoC), a method of serving a Stratum- 1 clock signal from an SoC and a device including the SoC. In one embodiment, the SoC includes: (1) a monolithic substrate, (2) a time code receiver clock source supported by the monolithic substrate and configured to receive a timing signal and generate a clock signal for the SoC and (3) at least one of a processor, memory and other SoC circuitry supported by the monolithic substrate and configured to receive the clock signal from the time code receiver clock source.

IPC Classes  ?

• G06F 1/04 - Generating or distributing clock signals or signals derived directly therefrom
• G06F 1/14 - Time supervision arrangements, e.g. real time clock

Abstract

A timekeeping device that tracks the time provided by a digital broadcast and the protocol of that broadcast, defined by its data frame structure and modulation scheme, are adapted to allow for superior performance of the timekeeping devices in terms of range of operation, immunity to interference, ability to operate with lower cost antennas due to enhanced link robustness, and reduced energy consumption. The timekeeping device operates with infrequent receptions of the broadcast by relying on independent self-compensation. This alleviates the need for frequent receptions to ensure timing accuracy while also reducing energy consumption. The mean and variability of successive measurements of drift are evaluated in the device and an estimated upper bound for the drift-estimation error is set. Based on this bound, the device employs a reception strategy than works with less frequent receptions, corresponding to the error in estimating the drift rather than to the magnitude of the drift itself.

IPC Classes  ?

• H04L 7/027 - Speed or phase control by the received code signals, the signals containing no special synchronisation information extracting the synchronising or clock signal from the received signal spectrum, e.g. by using a resonant or bandpass circuit
• H04B 1/12 - Neutralising, balancing, or compensation arrangements
• H04W 56/00 - Synchronisation arrangements