JP2011024012A

JP2011024012A - Ofdm modulation apparatus

Info

Publication number: JP2011024012A
Application number: JP2009167895A
Authority: JP
Inventors: Kenichi Uyama; 健一宇山
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2009-07-16
Filing date: 2009-07-16
Publication date: 2011-02-03

Abstract

<P>PROBLEM TO BE SOLVED: To provide an orthogonal frequency division multiplexing (OFDM) modulation apparatus capable of matching phases of a plurality of transport streams (TSs) in simple configuration. <P>SOLUTION: In an OFDM apparatus, a plurality of systems of TSs with arbitrary phases are connected and OFDM modulation is performed thereon. The OFDM apparatus comprises: an Fsync generation section 1a for generating a frame synchronizing signal from one system of TS among the plurality of systems of TSs; delay sections 2-1 to 2-n each for delaying the plurality of systems of TSs by a delay amount predetermined for each system; and phase adjusting sections 2a-2 to 2a-n each for detecting a phase difference between the one system of TS and the other systems of TSs based on the frame synchronizing signal generated by the Fsync generation section 1a and adjusting the delay amount of the other system based on the phase difference. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

この発明は、複数系統のトランスポートストリーム（ＴＳ：Transport Stream）を連結送信するための直交周波数分割多重（ＯＦＤＭ：Orthogonal Frequency Division Multiplexing）変調装置に関する。 The present invention relates to an Orthogonal Frequency Division Multiplexing (OFDM) modulation apparatus for concatenating and transmitting a plurality of transport streams (TS).

複数系統の放送ＴＳが入力され、放送ＴＳを連結送信するＯＦＤＭ変調器において、放送ＴＳは機器内で位相合わせを行う必要がある。通常は、前段機器とＯＦＤＭ変調器間に放送ＴＳとともにフレーム同期信号（Ｆｓｙｎｃ信号）を接続したり、外部に基準信号発生器等（Ｆｓｙｎｃ発生器）を準備して各機器に入力し、事前に位相合わせを行うことにより、ＯＦＤＭ変調器に入力する段階でほぼ位相を合わせた状態とし、ＯＦＤＭ変調器内では小さな位相合わせを行う構成とするだけであった（例えば、特許文献１及び２を参照。）。 In an OFDM modulator that receives a broadcast TS of a plurality of systems and transmits the broadcast TS in a connected manner, the broadcast TS needs to be phase-matched within the device. Usually, a frame synchronization signal (Fsync signal) is connected with the broadcast TS between the upstream device and the OFDM modulator, or a reference signal generator (Fsync generator) is prepared outside and input to each device in advance. By performing phase matching, the phase is almost matched at the stage of input to the OFDM modulator, and only a small phase matching is performed in the OFDM modulator (see, for example, Patent Documents 1 and 2). .)

特開２００８−７８９１７公報JP 2008-78917 A 特開２００７−２７４１２８公報JP 2007-274128 A

ところが、上述したような方法では、機器間の配線が多くなったり、基準信号発生器が必要となり、構成が複雑化する。また、ＯＦＤＭ変調器では調整可能な位相差の制約がある（任意の位相差に対応していない）という問題があった。 However, the above-described method requires more wiring between devices and requires a reference signal generator, which complicates the configuration. In addition, there is a problem in the OFDM modulator that there is an adjustable phase difference restriction (it does not support arbitrary phase differences).

この発明は上記事情に着目してなされたもので、その目的とするところは、簡易な構成で複数のＴＳ間の位相を合わせることができるＯＦＤＭ変調装置を提供することにある。 The present invention has been made paying attention to the above circumstances, and an object of the present invention is to provide an OFDM modulation apparatus capable of matching phases between a plurality of TSs with a simple configuration.

上記目的を達成するためにこの発明に係るＯＦＤＭ変調装置は、任意の位相の複数系統のＴトランスポートストリーム（ＴＳ：Transport Stream）を連結して直交周波数分割多重（ＯＦＤＭ：Orthogonal Frequency Division Multiplexing）変調するＯＦＤＭ装置であって、前記複数系統のＴＳのうち１系統のＴＳからフレーム同期信号を生成する生成部と、前記複数系統のＴＳを、系統毎に予め決められた遅延量で遅延する遅延部と、前記生成部で生成されたフレーム同期信号に基づいて前記１系統のＴＳと他の系統のＴＳとの間の位相差を検出し、前記位相差をもとに前記他の系統の前記遅延量を調整する調整部とを具備するものである。 In order to achieve the above object, an OFDM modulation apparatus according to the present invention concatenates a plurality of T transport streams (TSs) having arbitrary phases to perform orthogonal frequency division multiplexing (OFDM) modulation. An OFDM apparatus that generates a frame synchronization signal from one TS among the plurality of TSs, and a delay unit that delays the plurality of TSs by a predetermined delay amount for each system And detecting a phase difference between the one system TS and another system TS based on the frame synchronization signal generated by the generating unit, and based on the phase difference, the delay of the other system And an adjusting unit that adjusts the amount.

したがってこの発明によれば、簡易な構成で複数のＴＳ間の位相を合わせることができるＯＦＤＭ変調装置を提供することができる。 Therefore, according to the present invention, it is possible to provide an OFDM modulation apparatus capable of matching phases between a plurality of TSs with a simple configuration.

本発明に係るＯＦＤＭ変調装置の一実施形態を示す構成図。The block diagram which shows one Embodiment of the OFDM modulation apparatus which concerns on this invention.

以下、図面を参照しながら本発明の実施の形態を詳細に説明する。
図１は、本発明に係るＯＦＤＭ変調装置の一実施形態を示す構成図である。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of an OFDM modulation apparatus according to the present invention.

ＯＦＤＭ変調装置１００には、前段機器＃１〜ｎから任意の位相の複数系統の放送トランスポートストリーム（ＴＳ：Transport Stream）＃１〜ｎが入力される。これらの放送ＴＳ＃１〜ｎを連結送信するために、ＯＦＤＭ変調装置１００において、系統間の放送ＴＳの位相を合わせる必要がある。本実施形態では、一例として、＃１系統を基準とする場合について説明するが、いずれの系統を基準として構成しても良い。 The OFDM modulation apparatus 100 receives a plurality of broadcast transport streams (TSs) # 1 to n having arbitrary phases from the preceding devices # 1 to #n. In order to link and transmit these broadcast TS # 1 to n, it is necessary to match the phase of the broadcast TS between systems in the OFDM modulation apparatus 100. In this embodiment, as an example, a case where the # 1 system is used as a reference will be described. However, any system may be used as a reference.

同期部１−１〜ｎには所定のシステムクロック（図示せず）が与えられ、入力された放送ＴＳ＃１〜ｎは、このシステムクロックに同期制御される。＃１系統の同期部１−１のＦｓｙｎｃ生成部１ａは、放送ＴＳ＃１のＦｂｉｔ（frame_head_packet_flag）に基づいてフレーム同期信号（Ｆｓｙｎｃ）を生成する。Ｆｓｙｎｃ生成部１ａで生成されたＦｓｙｎｃは、基準信号として、その他の系統＃２〜ｎの遅延部２−２〜ｎに与えられる。 A predetermined system clock (not shown) is given to the synchronization units 1-1 to n, and the input broadcast TS # 1 to n are synchronously controlled by this system clock. The Fsync generation unit 1a of the # 1 system synchronization unit 1-1 generates a frame synchronization signal (Fsync) based on the Fbit (frame_head_packet_flag) of the broadcast TS # 1. The Fsync generated by the Fsync generation unit 1a is provided as a reference signal to the delay units 2-2 to n of the other systems # 2 to #n.

遅延部２−１〜ｎには、系統間の遅延差を吸収するように予め決められた遅延量が設定された遅延メモリ（図示せず）を有する。＃１系統の遅延部２−１は、放送ＴＳ＃１に対し、上記予め決められた遅延量で遅延処理を行ないＯＦＤＭ部３に入力する。 The delay units 2-1 to n have a delay memory (not shown) in which a predetermined delay amount is set so as to absorb the delay difference between the systems. The # 1 delay unit 2-1 performs delay processing on the broadcast TS # 1 with the predetermined delay amount, and inputs the result to the OFDM unit 3.

一方、その他の系統の遅延部２−２〜ｎの位相調整部２ａ−２〜ｎでは、Ｆｓｙｎｃ生成部１ａから与えられたＦｓｙｎｃに基づいて、＃１系統のＴＳと＃２〜ｎ系統のＴＳとの間の位相差を検出し、この位相差をもとに＃２〜ｎ系統の遅延量を調整する。すなわち、位相調整部２ａ−２〜ｎは、＃１系統のＴＳから生成されたＦｓｙｎｃと、該系統のＴＳ＃２〜ｎのＦｂｉｔからそれぞれ抽出したＦｓｙｎｃとの位相比較を行い、この位相差を上記予め決められた遅延量から差し引いて（または遅延量に足して）位相合わせを行う。遅延部２−２〜ｎは、放送ＴＳ＃２〜ｎに対し、上記位相調整部２ａ−２〜ｎでそれぞれ調整された遅延量で遅延処理を行ないＯＦＤＭ部３に入力する。 On the other hand, in the phase adjustment units 2a-2 to n of the delay units 2-2 to n of other systems, the TS of # 1 system and the TS of # 2 to n system are based on Fsync given from the Fsync generation unit 1a. And the delay amount of the # 2 to n systems is adjusted based on this phase difference. That is, the phase adjustment units 2a-2 to n perform a phase comparison between the Fsync generated from the # 1 system TS and the Fsync extracted from the Fbits of the TS # 2 to n of the system, respectively. Phase adjustment is performed by subtracting (or adding to the delay amount) from the predetermined delay amount. The delay units 2-2 to n perform delay processing on the broadcast TS # 2 to n with the delay amounts adjusted by the phase adjusting units 2a-2 to n, respectively, and input to the OFDM unit 3.

ＯＦＤＭ部３には、系統間の位相が揃った放送ＴＳ＃１〜ｎが入力される。ＯＦＤＭ部３は、位相が揃った放送ＴＳ＃１〜ｎをＯＦＤＭ変調し、ＯＦＤＭ信号を出力する。このように複数系統の放送ＴＳの位相合わせを行うことで、連結送信が可能となる。 Broadcast units TS # 1 to TS n having the same phase between the systems are input to the OFDM unit 3. The OFDM unit 3 performs OFDM modulation on the broadcast TS # 1 to n having the same phase and outputs an OFDM signal. In this way, linked transmission is possible by performing phase alignment of a plurality of broadcast TSs.

以上述べたように、上記実施形態では、基準系統のＴＳからＦｓｙｎｃを生成し、このＦｓｙｎｃに基づいて、その他の系統のＴＳを基準系統のＴＳと位相を合わせるようにする。このようにすることで、ＯＦＤＭ変調装置に入力する複数の放送ＴＳ間の位相関係が任意であっても、放送ＴＳとともにＦｓｙｎｃを入力したり、基準信号発生器を設けたりすること無く、簡易な構成で複数の放送ＴＳ間の位相合わせを容易に行うことができる。 As described above, in the above-described embodiment, Fsync is generated from the TS of the reference system, and the TSs of the other systems are matched in phase with the TS of the reference system based on this Fsync. In this way, even if the phase relationship between a plurality of broadcast TSs input to the OFDM modulation device is arbitrary, it is easy to input Fsync together with the broadcast TS or to provide a reference signal generator. With the configuration, phase alignment between a plurality of broadcast TSs can be easily performed.

なお、この発明は、上記実施形態そのままに限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で構成要素を変形して具体化できる。また、上記実施形態に開示されている複数の構成要素の適宜な組み合せにより種々の発明を形成できる。例えば、実施形態に示される全構成要素から幾つかの構成要素を削除してもよい。さらに、異なる実施形態に亘る構成要素を適宜組み合せてもよい。 Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

１００…ＯＦＤＭ変調装置、１−１〜ｎ…同期部、１ａ…Ｆｓｙｎｃ生成部、２−１〜ｎ…遅延部、２ａ−２〜ｎ…位相調整部、３…ＯＦＤＭ部。 DESCRIPTION OF SYMBOLS 100 ... OFDM modulation apparatus, 1-1 to n ... Synchronizing part, 1a ... Fsync production | generation part, 2-1 to n ... Delay part, 2a-2-n ... Phase adjustment part, 3 ... OFDM part.

Claims

An OFDM apparatus that performs orthogonal frequency division multiplexing (OFDM) modulation by concatenating a plurality of transport streams (TS: Transport Stream) of an arbitrary phase,
A generating unit that generates a frame synchronization signal from one TS among the plurality of TSs;
A delay unit that delays the TS of the plurality of systems by a predetermined delay amount for each system;
Based on the frame synchronization signal generated by the generation unit, a phase difference between the one system TS and another system TS is detected, and the delay amount of the other system is determined based on the phase difference. An OFDM modulation apparatus comprising: an adjustment unit for adjustment.

2. The OFDM modulation apparatus according to claim 1, wherein the generation unit generates the frame synchronization signal based on Fbit (frame_head_packet_flag) of the one system TS.