Re: assignment #3 - 5.13

Ed Casas (edc@ece.ubc.ca) Wed, 9 Feb 2000 13:09:01 -0800 

Date: Wed, 9 Feb 2000 13:09:01 -0800
From: Ed Casas <edc@ece.ubc.ca>
Subject: Re: assignment #3 - 5.13



On Tue, Feb 08, 2000 at 09:45:46PM -0500, Anita Lei wrote:

> Does anyone know if channel spectral efficiency is same as
> channel capacity?  If not, then what is channel spectral
> efficiency?

Unfortunately, the author is inconsistent with his terminology
"spectral efficiency" is what he calls "bandwidth efficiency in
section 5.4.1.

Channel capacity is the theoretical limit to spectral efficiency
and is given by Shannon's capacity formula (equation 5.37).

The four modulation schemes in question 5.13 are described in
detail in Chapter 10.  The channel spacings and data rates are
summarized below:

IS-54   30 kHz           48.6 kbps      (Table 10.2)
GSM    200 kHz          279.8 kbps      (Table 10.3)
PDC     25 kHz           42.0 kbps      (section 10.8)
IS-95 1.25 MHz          (variable, maximum per user is 14.4 kbps, 
                                chip rate is 1.2288 Mchips/s)
-- 
Ed Casas   edc@ece.ubc.ca   http://casas.ece.ubc.ca   +1 604 822-2592