Acoustic规范和测试

合集下载
  1. 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
  2. 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
  3. 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
• The Receiving Loudness Rating (RLR) is a means of expressing the receiving frequency response based on objective single tone measurements in a way which relates to how a speech signal would be perceived by a listener. 单音信号测量基础上的接收频率响应,测量涉及到语音信号是 如何被收听者接收到的。 1) The nominal Receiving Loudness Rating (RLR) shall be 2 +/3 dB. If a user controlled receive volume control is provided the equipment shall meet this nominal value for at least one setting of the control. 2) If a user controlled receive volume control is provided the Receive Loudness Rating (RLR) shall not be less than -13 dB when the control is set to maximum. Initial conditions:The DAI of the MS is connected to the SS and is set to the operating mode "Test of acoustic devices and A/D & D/A".
Frequency (Hz) Upper Limit(dB) 100 200 300 500 1000 3000 3400 4000 -12 0 2 * 0 2 2 2
Lower Limit (dB)
-7 -5 -5 -5 -10
4 Receiving loudness rating(RLR) (接收声音响度等级)
3 Receiving sensitivity/frequency response
• The receiving sensitivity frequency response is, as a function of the input test tone frequency, the ratio expressed in dB between the output sound pressure in the artificial ear and the input level, represented by the PCM bit stream at the Digital Audio Interface (DAI), required to obtain this. • 人工耳处的输出声压和DAI处用PCM比特流描述的输 入等级的比值,用dB来表示。(ERP/DAI) • 测试目的和要求是符合GSM规范,如下表:
5.2 Listener Side Tone Rating (LSTR) • 背景侧音等级是在仿真量测电话在吵杂 环境中使用时由送话端回到受话端的量。 • The value of the Listener Sidetone Rating (LSTR) shall not be less than 15 dB.
Acoustic规范和测试
有关声音的基本知识
• 声音的定义:声音是很多振动波的组合而成 , 此振动波的频率能 被人耳接收到的范围就是声音。 • 声音的单位:声音的单位是用分贝(dB)来量测计算的。声压指针 ( SOUND PRESSURE LEVEL) 的定义是指单位面积所受到的压力 ( N/M2 ) 。N: 牛顿, M2:米平方。 • 标准音源:标准音源是标准麦克丰后量测到 1 Vrms 的电压信号,此1KHZ的发 音源必须为94dBspl。 • 1 Pa = 94 dBspl • 1 Pa = 0 dBpa SPL = 20 log 10 ( X / 20 exp –6 pa ) If x = 1 pa • SPL = 94 dB
• The Sending Loudness Rating (SLR) is a means of expressing the sending frequency response based on objective single tone measurements in a way which relates to how a speech signal would be perceived by a listener. • 单音信号测量基础上的发射频率响应,测量涉及到语音信号是如 何被收听者接收到的。 • The Sending Loudness Rating (SLR) shall be 8 +/- 3 dB. • Initial conditions:The DAI of the MS is connected to the SS and is set to the operating mode "Test of acoustic devices and A/D & D/A".
6 Telephone Acoustic coupling Loss (TAL) 6.1 Echo Loss (EL)
• The echo loss is the path loss from the input of the reference speech encoder of the SS to the output of the reference speech decoder of the SS. • SS:system simulator • SS参考语音编码的输入与SS参考语音解码的比值。 • shall be at least 46 dB. • Initial conditions:The DAI of the MS is connected to the SS and is set to the operating mode "Normal operation". • The SS sets up a speech call according to the generic call set up procedure.
6.2 Stability margin
• 目的: 测试手机的听筒放置在光滑面时是否会 产生哨叫不安定的现象。 • 测试方法: 将手机之音量调到最大的位置,受 话器面朝下,然后放置在光滑面的木卓上。由 仪器端来回注入一音源到受话器之使其产生回 授振动效应。 • 规格: The stability margin shall be at least 6 dB.
5 Side tones 5.1 Side Tone Masking Rating(STMR) (侧音屏蔽等级)
• expressing the path loss from the artificial mouth to the artificial ear based on objective single tone measurements in a way that relates to how a speaker will perceive his own voice when speaking or how a listener will perceive the background noise picked up by the microphone. • 表示从人工嘴到人工耳的路径损耗,对单音信号的测量,并涉及 到说话者怎样接收到自己的声音或麦克风接收到背景噪音。 • The nominal value of the Side Tone Masking Rating (STMR) shall be 13 +/- 5 dB. Where a user controlled receiving volume control is provided the STMR shall meet the requirement at the setting where the RLR is equal to the nominal value.
Frequency (Hz)) Upper Limit (dB Lower Limit (dB)
100 200 300 1000 2000 3000 3400 4000 -12 0 0 0 4 4 4 0
-12 -6 -6 -6 -9
2 Sending loudness rating(SLR) (发送声音响度等级)
GSM ACOUSTIC测试设备
• • • • • 1. 测试固定架 ( Telephone Test Head ) : B&K 4602B 2. 仿真耳 ( Ear Simulator ) : B&K 4185 ( type 1) 3. 人工嘴 ( Artificial Mouth ) : B&K 4227 4. 标准音源校正器 ( Acoustic Calibrator ) B&K 4231 5. 仿真耳之电源供应器 ( Microphone Power Supply ) B&K 2690A0S2 6. 音频功率放大器 ( Audio Power Amplifier ) WQ1105 7. GSM音频分析仪 ( GSM Audio Analyzer ) R&S UPL- 16 with B8 OR B&K 3108 8. 数字模拟转换接口 ( DAI Interface Box ) GSM solution vendor must supply. 9. 个人计算机 ( Personal Computer ) PC-486 10. GSM 射频分析仪 ( Air Interface for GSM ) R&S CMD55/65 with option CMD-B5. 11. GSM Acoustic 测试专用软体 ( 配合厂商提供 )。 50 db(A) 的隔音室 ( Acoustic Shield Room )
• •

• •
• •
1 Sending sensitivity/frequency response
• The sending sensitivity frequency response is, as a function of the input test tone frequency, the ratio expressed in dB between the output level, represented by the PCM bit stream at the Digital Audio Interface (DAI) and the input sound pressure in the artificial mouth required to obtain this. • 有关语音输入频率的测试,用PCM比特流来描述的在 DAI处的输出与人工嘴处的输入的比值,单位是dB。 (DAI/MRP) • 测试目的和要求是符合GSM规范,如下表:
7 Distortion(失真) 7.1 Sending
• The transmit signal to total distortion ratio is a measure of the linearity of the transmitter equipment • 发送信号对总失真的比值,测量手机发射设备 的线性度。 • 测试方法: 先在人工嘴的MRP 处产生1KHz音 频使其在DAI 的输入端呈现0dBm0 的信号。此 信号被校正为0dB ARP( Acoustic Reference Point )。然后依照下例表格规定,其送话失真 度不得小于其要求。
相关文档
最新文档