Transmission architecture of transmitter

• US 8,238,507 B2
• Filed: 06/03/2008
• Issued: 08/07/2012
• Est. Priority Date: 03/04/2008
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Industrial Technology Research Institute
• Inventors: Sheu, Chorng-Ren, Tseng, Ming-Chien, Chen, Ching-Yung
• Primary Examiner(s): Payne, David C.
• Assistant Examiner(s): Cadeau, Wednel
• Application Number:
  US12/131,930
• Publication Number:
  US 20090225895A1
• Time in Patent Office: 1,526 Days
• Field of Search: 370/344, 370/208, 370/204, 370/465
• US Class Current: 375/376
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2614 Peak power aspects

Abstract

This invention provides a transmission architecture of transmitter which includes a forestage module, a pilot insertion, a scramble selector, and a backstage module. A frequency domain data symbol is transmitted by the forestage module. A pilot signal is inserted in the frequency domain data symbol by the pilot insertion, and a frequency domain pilot symbol is produced. The frequency domain pilot symbol performed a scramble operation and a select operation with certain scramble patterns by the scramble selector, and a requirement symbol is produced. The requirement symbol is converted into the transmitted signal by the backstage module. Because the use of the scramble operation and the select operation from the scramble selector, the transmission architecture of transmitter provided by this invention can both reduce the PAPR and increase the multi-cell diversity gain in an OFDM single frequency network system.

Claims

1. A transmission architecture of a transmitter, for reducing Peak to Average Power Ratio (PAPR) of the transmitted signals and increasing multi-cell diversity gain without requiring descramble operation in a corresponding receiver, the architecture comprising:

a forestage module transmitting a frequency domain data symbol;

a pilot insertion, connected to the forestage module, receiving the frequency domain data symbol, and inserting a pilot signal in the frequency domain data symbol to produce a frequency domain pilot symbol, so as to only estimate the channel effect;

a scramble selector, connected to the pilot insertion, generating a plurality of scramble patterns for every frequency domain pilot symbol so as to perform a scramble operation with the frequency domain pilot symbol, and then performing a select operation from among the plurality of scrambled frequency domain pilot symbols to select a scrambled frequency domain pilot symbol with minimum PAPR to produce a requirement symbol, wherein the plurality of the scramble patterns generated by the scramble selector are irrelevant to each other, but a part of the scramble parameters in each of the scramble patterns are relevant to one another as long as there is a little randomness; and

a backstage module, connected to the scramble selector, for processing and transmitting the requirement symbol out of the transmitter so as to provide a corresponding receiver with the transmitted requirement symbol which can be recovered by the receiver without any corresponding descramble operation.

2. The transmission architecture of a transmitter according to claim 1, wherein the forestage module comprises:

a data source bit stream generator, for generating a frequency domain data bit stream to be transmitted;

a channel encoder, coupled to the data source bit stream generator, for receiving the frequency domain data bit stream, and performing channel encoding on the frequency domain data bit stream to produce an encoded frequency domain data bit stream;

an interleaver, coupled to the channel encoder, for interleaving the encoded frequency domain data bit stream to produce an interleaved encoded frequency domain data bit stream; and

a mapper, coupled between the interleaver and the pilot insertion, for mapping the interleaved encoded frequency domain data bit stream into the frequency domain data symbol, and transmitting the frequency domain data symbol to the pilot insertion.

3. The transmission architecture of a transmitter according to claim 1, wherein the backstage module comprises:

a guard interval (GI) insertion, coupled to the scramble selector, for receiving the requirement symbol, and inserting a guard interval (GI) into the requirement symbol; and

an antenna unit, coupled to the GI insertion, for transmitting the requirement symbol with the GI out of the transmitter in the form of electromagnetic waves.

4. The transmission architecture of a transmitter according to claim 1, wherein the scramble selector comprises:

a scrambler, coupled to the pilot insertion, for generating the scramble patterns, and performing the scramble operation between the scramble patterns and the frequency domain pilot symbol to produce a plurality of time domain scramble symbols; and

a selector, coupled between the scrambler and the backstage module, for performing the select operation to select one of the time domain scramble symbols outputted from the scrambler to produce the requirement symbol, and then transmitting the requirement symbol to the backstage module.

5. The transmission architecture of a transmitter according to claim 4, wherein the scrambler comprises:

a scramble parameter generator, for generating the scramble patterns;

a multiplier, coupled to the scramble parameter generator and the pilot insertion, for multiplying the scramble patterns with the frequency domain pilot symbol, so as to produce a plurality of frequency domain scramble symbols; and

an inverse fast Fourier transformer, coupled to the multiplier, for converting the frequency domain scramble symbols into the time domain scramble symbols.

6. The transmission architecture of a transmitter according to claim 4, wherein the selector comprises:

a peak-to-average power ratio (PAPR) calculator, coupled to the scrambler, for calculating and then outputting the PAPRs of the time domain scramble symbols;

a minimum selector, coupled to the PAPR calculator, for selecting and then outputting an index number of a scramble pattern with a relative minimum PAPR according to the output values of the PAPR calculator; and

a switch, coupled between the scrambler, the minimum selector, and the backstage module, for receiving the time domain scramble symbols, then selecting one of the time domain scramble symbols as the requirement symbol according to the index number of the scramble pattern from the output of the minimum selector, and then transmitting the requirement symbol to the backstage module.

7. The transmission architecture of a transmitter according to claim 4, wherein the scramble operation comprises multiplying the frequency domain pilot symbol with the scramble patterns and then performing an inverse fast Fourier transformation operation.

8. The transmission architecture of a transmitter according to claim 1, wherein the scramble selector comprises:

a scrambler, coupled to the pilot insertion, for generating the scramble patterns, and performing the scramble operation between the scramble patterns and the frequency domain pilot symbol to produce a plurality of frequency domain scramble symbols; and

a selector, coupled to the scrambler and the backstage module, for selecting one of the frequency domain scramble symbols outputted from the scrambler as a frequency domain requirement symbol, and performing an inverse fast Fourier transformation operation to form the requirement symbol for being output to the backstage module.

9. The transmission architecture of a transmitter according to claim 8, wherein the scrambler comprises:

a scramble parameter generator, for generating the scramble patterns; and

a multiplier, coupled to the scramble parameter generator and the pilot insertion, for multiplying the scramble patterns with the frequency domain pilot symbol, so as to produce the frequency domain scramble symbols.

10. The transmission architecture of a transmitter according to claim 8, wherein the selector comprises:

a requirement selector, coupled to the scrambler, for selecting one of the frequency domain scramble symbols as the frequency domain requirement symbol; and

an inverse fast Fourier transformer, coupled between the requirement selector and the backstage module, for performing the inverse fast Fourier transformation operation to convert the frequency domain requirement symbol into the requirement symbol.

11. The transmission architecture of a transmitter according to claim 8, wherein the scramble operation comprises multiplying the frequency domain pilot symbol with the scramble patterns.

12. The transmission architecture of a transmitter according to claim 4, wherein the select operation comprises selecting one time domain scramble symbol with a relative minimum PAPR from the time domain scramble symbols to serve as the requirement symbol.

13. The transmission architecture of a transmitter according to claim 1, wherein the scramble patterns generated by the scramble selector are irrelevant to each other.

14. The transmission architecture of a transmitter according to claim 1, wherein the scramble operation comprises a scramble mode of frequency domain.

15. The transmission architecture of a transmitter according to claim 1, wherein the scramble operation comprises a scramble mode of both the frequency domain and time domain.

16. The transmission architecture of a transmitter according to claim 1, wherein the transmitter is an orthogonal frequency division multiplexing (OFDM) transmitter.

17. The transmission architecture of a transmitter according to claim 16, wherein the OFDM transmitter is applied in a single frequency network (SFN) system.

18. The transmission architecture of a transmitter according to claim 17, wherein the scramble patterns generated by the scramble selectors in the transmitters of different cells in the SFN system are irrelevant to each other.