Method for Reception of Dvb-H Signals and Dvb-H Receiver

• US 20080212688A1
• Filed: 07/10/2006
• Published: 09/04/2008
• Est. Priority Date: 07/20/2005
• Status: Active Grant

• Current Assignee: MaxLinear Communications, LLC (f/k/a Entropic Communications, LLC) (Maxlinear Incorporated)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Aue, Volker
• Granted Patent: US 8,279,943 B2
• Time in Patent Office: Days
• US Class Current: 375/240.26
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The invention relates to a Method for reception of DVB-H signals wherein a MPEG transport stream (MPEG-TS) is grouped into packets belonging to a certain IP data stream and forming bursts in time slices, the MPEG-TS is modulated into OFDM symbols, these symbols are grouped in frames, the frames themselves are grouped in superframes. A receiver is notified about a relative time from a first burst to transmission of the next burst and the receiver is switched off between the first and the next burst. The invention further relates to a DVB-H receiver. The invention solves the problem is to reduce the power consumption of DVB-H receivers by reducing the switch on time of the receiver by providing the receiver with means for maintaining accurate course symbol timing within the symbol with an accuracy better than 25 ppm and by switching on the receiver exactly at the superframe boundary.

Claims

1. Method for reception of DVB-H signals wherein a MPEG transport stream is grouped into packets belonging to a certain IP data stream and forming bursts in time slices, the MPEG-TS is modulated into OFDM symbols, these symbols are grouped in frames, the frames themselves are grouped in superframes and symbols, frames and superframes are provided with numbers, whereas a transmitter does not change the transmission parameters (FFT mode, guard interval, code rate, modulation format) between successive bursts and a receiver is notified about a relative time from a first burst to transmission of the next burst and the receiver is switched off between the first and the next burst comprising the steps:

accurately calculating the receive time of the next burst from the DVB-H delta-t time received in the first burst;

setting a wake up timer and powering down the receiver;

powering up the receiver for reception of the next burst exactly at the superframe boundary;

executing signal acquisition

calculating the symbol number and frame number of the first symbol that contains relevant data to be modulated within the actual superframe;

calculation the number of bis to be discarded from the MPEG-TS to align with a boundary of a MPEG-TS-packet

discarding the bits starting demodulation at the boundary of the MPEG-TS-packet.

2. Method according to claim 1, whereas the accuracy of the receive time of the next burst is better than 25 ppm.

3. Method according to claim 1 whereas the DVB-T based steps in the receiver

Detection of the channel bandwidth (8,7,6, or 5 MHz)

Detection of the guard interval duration

Detection of the FFT mode (8k, 4k, or 2k)

Detection of the modulation format

Detection of the code rate

Detection of hierarchical transmission

Detection of the frame and super frame boundaries are skipped.

4. Method to claim 1 whereas the number of bits to be discarded after convolutional decocoding in the viterbi processor is calculated as the remainder of the integer division of the bits contained in all the symbols between the last super frame boundary and the demodulation start, and the number of bits contained in one MPEG-TS packet.

5. DVB-H receiver consisting of a RF module, a DVB-T baseband receiver, an analog-to-digital converter, a clock and a protocol processor, is provided with means for maintaining accurate course symbol timing within the symbol with an accuracy better than 25 ppm.

6. DVB-H receiver according to claim 5, wherein the receiver is provided with an accurate standby clock.

7. DVB-H receiver according to claim 5, wherein the protocol processor is provided with an accurate standby clock.

8. DVB-H receiver according to claim 5—

wherein the protocol processor is enabled for

MPEG-TS filtering

DVB-H time-slice control

DVB-H IP decapsulation

System standby and power down control

Receive control to DVB-T receiver

Interface to host processor.

9. DVB-H receiver according to claim 5 wherein the local timer is adjusted according to the time recovered from the received signal.

10. DVB-H receiver according to claim 5—

wherein the DVB-T receiver is provided with the ability to skip

Detection of the channel bandwidth (8,7,6 or 5 MHz)

Detection of the guard interval duration

Detection of the FFT mode (8k, 4k, or 2k)

Detection of the modulation format

Detection of the code rate

Detection of hierarchical transmission

Detection of the frame and super frame boundaries.

11. DVB-H receiver according to claim 10 wherein the receiver has the ability to start demodulation at a timing instant given by the protocol processor.

12. DVB-H receiver according to claim 10 wherein the protocol processor calculates the timing instance for demodulation start and/or acquisition or synchronisation start and the number of bits to be discarded.